JOURNAL OF PHILOSOPHY Volume 30, Issue 2 2016

Special issue: New Developments in Philosophy of Time Guest edited by Florian Fischer

Florian Fischer: Philosophy of time: A slightly opinionated intro- duction ...... 3

Jesse M. Mulder: Defining Original Presentism ...... 29

Florian Fischer: Carnap’s Logic of Science and Reference to the Present Moment ...... 61

Cord Friebe: Time Order, Time Direction, and the Presentist’s View on Spacetime ...... 91

Sonja Deppe: The Mind-Dependence of the Relational Structure of Time (or: What Henri Bergson Would Say to B-theorists) . . . . 107

Pamela Zinn: Lucretius On Time and Its Perception ...... 125 EDITORIAL KRITERION – Journal of Philosophy is a forum for contributions in any field of analytic philosophy. We welcome submissions of previously unpublished papers, not under consideration for publication anywhere else. Submissions are reviewed in double-blind peer review mode. Con- tributions should meet the following conditions: (1) The content must be philosophical. (2) The language must be intelligible to a broader readership. (3) The contribution must contain a traceable argumentation. The length should be between 4000 and 8000 words. Only contributions in English (preferred) and German are accepted.

IMPRESSUM

Editors-in-Chief: Christian J. Feldbacher-Escamilla, Alexander Gebharter Editorial Board: Albert J. J. Anglberger, Laurenz Hudetz, Christine Schurz, Christian Wallmann Address: Franziskanergasse 1, 5020 Salzburg, Austria. E-Mail: [email protected] Web: http://www.kriterion-journal-of-philosophy.org Indexing: KRITERION – Journal of Philosophy is indexed and abstracted by The Philosopher’s Index and EBSCOhost Humanities Source. Infor- mation about the journal’s ranking is available at SJR. The journal was also approved of satisfying the ERIH (European Reference Index for the Humanities) criteria: ERIH PLUS. Copyright: The copyright remains with the authors. ISSN: 1019-8288 Preface

Florian Fischer

The idea to make this special issue was born during the Tensed vs Tense- less Theory symposium (http://tense-less.weebly.com) at the SOPhiA conference in Salzburg 2014. There, also, the Society for Philoso- phy of Time (SPoT - http://s-p-o-t.weebly.com) was founded. During the subsequent SPoT discussion groups and workshops (http://s-p-o- t.weebly.com/events.html) some of the papers of this volume have been presented, in one form or other. As this special issue corporealised the SPoT was growing. I’m grateful to everybody who was part of this exiting journey, but especially I want to thank Christian J. Feldbacher- Escamilla and Alexander Gebharter from KRITERION — Journal of Philosophy to make this special issue possible. As the SPoT is set up very broadly, this special issue aims at de- picting philosophy of time in all of its varieties. After ‘A Slightly Opin- ionated Introduction’ into philosophy of time, Jesse Mulder questions the set up of the eternalism/presentism debate in his ‘Defining Original Presentism’. His paper reflects the cutting edge of contemporary debate about the nature of time. Then, my paper touches upon the intersection of philosophy of time and philosophy of science, investigating the rela- tion between ‘Carnap’s Logic of Science and Reference to the Present Moment’. Cord Friebe’s ‘Time Order, Time Direction, and the Presen- tist’s View on Spacetime’ covers the intersection between philosophy of physics and philosophy of time. The last part of the special issue has a more historical twist – albeit still being systematic. Sonja Deppe’s ‘The Mind-Dependence of the Relational Structure of Time’ is concerned with more recent history (Henri Bergson), while Pamela Zinn’s ‘Lucretius On Time and Its Perception’ examines more ancient history.

Florian Fischer University of Bonn Institut f¨urPhilosophie Am Hof 3 - 5 53113 Bonn Kriterion – Journal of Philosophy, 2016, 30(2):1–2. http://www.kriterion-journal-of-philosophy.org c 2016 The author

Philosophy of time: A slightly opinionated introduction

Florian Fischer

There are several intertwined debates in the area of contemporary philos- ophy of time. One field of inquiry is the nature of time itself. Presentists think that only the present moment exists whereas eternalists believe that all of (space-)time exists on a par. The second main field of inquiry is the question of how objects persist through time. The endurantist claims that objects are three-dimensional wholes, which persist by being wholly1 present, whereas the perdurantist thinks that objects are four- dimensional and that their temporal parts are the bearers of properties. The third debate in the field of contemporary philosophy of time is about tense- versus tenseless theory. Tensers are at odds with detensers about the status of the linguistic reference to the present moment. These are only very crude characterizations and it is even disputed by some ad- vocates of the corresponding positions that they are accurate. However this very sketchy picture already reveals a fundamental difference: The eternalism/presentism and endurance/perdurance discussions belong to the field of metaphysics, whereas tense is in the first instance a linguistic phenomenon.

Among the many fields of philosophy, there are two that are more intimately interconnected than most but whose practi- tioners have too long pursued relatively independent paths. On the one hand, there are philosophers of language, who have devoted much attention to indexicals (‘now’, etc.), tem- poral operators (‘it has been the case that’, etc.), and tensed sentences. On the other hand, there are the philosophers of tensed and tenseless time (also called A-time or B-time, dynamic time or static time, etc.). [27, p. 1]

Jokic and Smith’s claim can be generalized for philosophy of time as a whole: There are prima facie distinct debates about the nature of time, the persistence of objects and the reference to the present moment. However these debates are interrelated and the position held regarding one of them may have implications upon the options for the other debates.

Kriterion – Journal of Philosophy, 2016, 30(2):3–28. http://www.kriterion-journal-of-philosophy.org c 2016 The author 4 KRITERION – Journal of Philosophy, 2016, 30(2):3–28

And even if systematic links between the debates have to be rejected, the choices in one debate often de facto mirror the choices in the others: ‘the line between philosophy of language and metaphysics is blurred and, one is tempted to view them instead as a continuum’ [27, p. 3–4]. This introduction proceeds as follows: In section1 the debate between eternalists and presentists is depicted. Section2 then introduces the problem of change and the alleged solutions by the perdurantist and endurantist. The positions of the tense and tenseless theoreticians are presented in section3. Lastly some inter-theoretical links and various package-deals are presented in section4.

1 Eternalism/Presentism

Eternalists and presentists debate about the nature of time.2 While presentists think that the present is ontologically outstanding, eternalists hold that the whole (space-)time3 is ontologically on a par or, put differ- ently, ‘according to the presentist, only present entities exist; according to the eternalist, past and future entities also exist’[63, p. 256]. Main works of eternalists include David Lewis’s On the Plurality of Worlds [32], Willard Van Orman Quine’s Word & Object [57] and Ted Sider’s Four-Dimensionalism [59]. Seminal contributions to the debate by pre- sentists include Bigelow’s Presentism and Properties [5], Ned Markosian’s A Defence of Presentism [35], Trenton Merricks’ Persistence, Parts, and Presentism [43] and Dean Zimmerman’s Temporary Intrinsics and Presentism [67]. Eternalism and presentism come in different kinds of formulations. They can be formulated concerning time itself or the occupants of time. I will not discuss here whether these formulations are equivalent since for our introductory purpose it suffices to sketch the big picture. In the time-formulation, Ted Sider, an eternalist, characterises presentism as ‘the doctrine that only the present is real’ [60, p. 325]. Here he is talking about time itself, so according to Sider’s presentist every non-present time is not real. The future is not yet real and the past not anymore, one might want to add. When formulated with the occupants in mind, the debate is about ‘what there is’ or ‘about the range of things to which we’re ontologically committed’ [11, p. 211]. Sider writes: ‘A presentist thinks that everything is present; more generally, that, necessarily, it is always true that everything is (then) present’ [60, p. 326]. Here the contrasting class does not consist of the other times (future and past times), but of the non-present objects. Dinosaurs do not belong to ‘everything’ since Florian Fischer: Introduction 5

they are not present, according to Sider’s presentist. Phrasing it in slightly more formal terms, the ‘everything’ suggests a general quantifier ∀. Together with the mantra that ‘to be is to be the value of a bound variable’ [56][54] we can characterise presentism in the way Ned Markosian did: ‘According to Presentism, if we were to make an accurate list of all the things that exist – i. e. a list of all the things that our most unrestricted quantifiers range over – there would be not a single non-present object on the list’ [36]. As some have argued that the presentist cannot even articulate her own view consistently4, formulations matter a great deal here. Note that Sider speaks of ‘real’ while Markosian uses ‘exists’. Asked whether Socrates exists, the presentist could give the (plausible) answer ‘No, he existed’. The presentist thus could acknowledge that Socrates is presently not existing. However this denial does not imply that Socrates is on a par with Santa according to the presentist. In contrast to Santa, Socrates, as far as we know, existed. ‘Socates exists’ used to be true, while ‘Santa exists’ was never true. The presentist thus neither has to bulldoze the difference between Socrates and Angela Merkel nor the difference between Socrates and Santa. In contrast to this, it sounds much more implausible to say that Socrates is not real, just because he is not present. We leave the matter be and turn to the presentist’s antagonist eternalism. Eternalism states that ‘there are such things as merely past and future5 entities’ [60, p. 326]. You may have noticed that this is the occupants-formulation and that with ‘there is’ we have an existential quantifier ∃. Sider’s formulation is quite careful. The ‘merely’ excludes entities which are also present, entities with which the presentist (in Sider’s fashion) would not have a problem. Furthermore, the existential quantifier is very modest: One (merely) past entity suffices to make ‘there are such things as merely past and future entities’ true. Thus even at the last moment of time, where there are no future entities, Sider’s formulation could still differentiate presentism from eternalism. Trenton Merricks supplies a time-formulation of eternalism: ‘Eter- nalism says that all times are equally real.’ [42, p. 103]. The presentist could actually agree in wording to this, if not in spirit, of course. For the presentist the ‘all’ will range over the present only. It is thus trivially true for her that all times are equally real, as there is only one time. The idea behind the time-formulation of eternalism is clear however. There are times other than the present and these are as real as the present. It is not the case that the future and the past subsist, while only the present exists. Even my earlier formulation that the eternalists believe ‘that all of 6 KRITERION – Journal of Philosophy, 2016, 30(2):3–28

(space-)time exists on a par’ is not enough to define eternalism, since all of (space-)time could be unreal. Then it would be ‘on a par’ but not in the way the eternalist wants. The formulation may suffice to distinguish presentism from eternalism, however. Merricks also offers a different characterisation of eternalism: ‘Objects existing at past times and objects existing at future times are just as real as objects existing at the present.’ [42, p. 103]. This is the occupants formulation, obviously. Once again I would query that the presentist must not deny the reality of (merely – which Merricks doesn’t mention) past and future objects but maybe non-existing real entities seem strange. Let’s fight squalidness with abundance and hear another characterisation of eternalism, this time from David Lewis:

‘There is nothing so far away from us as not to be part of our world. Anything at any distance at all is to be included. Likewise the world is inclusive in time. No long-gone ancient Romans, no long-gone peterodactyls, no long-gone primordial clouds of plasma are too far in the past, nor are the dead dark stars too far in the future to be part of this same world.’ [32, p. 1]

Lewis’, admittedly rhetorically brilliant, quote nicely captures the egalitarian tendencies of the eternalist. All times are part of ‘this same world’ and time is like space. The former we have heard before, while the latter offers a new aspect of eternalism. Eternalists often overemphasize that time is just one dimension of space-time and thus hold that time and space are alike, or at least that ‘time is very much like the dimensions of space’ [36]. They believe that ‘x is later then y’ is just another transitive, irreflexive, asymmetrical relation, like ‘x is left of y’. Eternalists ‘would like to stand in thought outside the whole temporal process and describe the world from a point which has no temporal perspective at all, but surveys all temporal positions at a single glance. [. . . ] The different points of time have a relation of temporal precedence between themselves, but no temporal relation to the viewpoint of the description.’ [14, p. 369]. Dummett’s quote hints at the fear of the eternalist that the presentist’s ontological prioritisation of the present as the point of view of description deprives presentism of objectivity. Perhaps this fear is justified, perhaps not.6 Of course we cannot end the (eternal?) battle of presentists and eternalists in this meagre introduction. Let us listen to some allegedly soothing tunes instead: ‘These two ways of thinking, the way of time and Florian Fischer: Introduction 7

history and the way of eternity and of timelessness, are both part of man’s effort to comprehend the world in which he lives. Neither is comprehended in the other nor reducible to it.’ [49, p. 69]. This quote by Oppenheimer can be used to challenge the very foundation of the eternalist/presentist debate. Maybe they are not two mutually exclusive alternatives. Maybe they could even be combined: ‘Hybrid views acknowledge that the world may be thought of as an existent four-dimensional entity, [. . . ] but retain the idea that there is something special about present times’ [10, p. 590] – with this, Craig Callender hints at a possible combination of eternalsim and presentism. Another way to question the classical eternalism/presentism distinc- tion is to say that it is not exhaustive. Presentists hold the present dear, while eternalists believe all of (space-)time to be ontologically homoge- neous. What of the people who want to distinguish between the past and the future? You believe the past to be settled, while the future holds a variety of possible developments? Maybe then the ‘growing block’ theory is something for you. According to its proponents ‘only objects that are either past or present – but not objects that are future – exist.’ [36]. According to this theory, the past and present are on a par while the future is differentiated from them. The present just happens to be the ‘edge of existence’, i. e. the border of the block. And this block is growing, because ‘the universe is always increasing in size, as more and more things are added on to the front end (temporally speaking)’ [36]. This growing of the block is supposed to be the reason why the present always differs in content. We can distinguish the question whether the present is ontologically special or not from the question whether what exists changes over time or not. Following Cord Friebe’s [23, p. 43] terminology, we call a view according to which existence is time relative ‘dynamic’ and one where this is not the case ‘static’. Classic eternalism is static, as neither the present is distinguished nor what there is changes over time. On the other end of the spectrum we have classic presentism where the present is so special that all there is, is present. One might think that presentism is the only dynamic theory but the recently mentioned ‘growing block’ is dynamic as well, at least according to Friebe [23, p. 44]. A static theory besides classical eternalism is the so-called ‘moving spotlight’ theory. According to the moving spotlight theory, the present is like a spotlight (hence the name) which ‘sheds its light’ on the present point in time. It moves (yes!) alongside the time line, thus always rendering a different time present. You may be wondering now with which speed the present moves, 8 KRITERION – Journal of Philosophy, 2016, 30(2):3–28

or how it moves at all, if the ‘time line’ is supposed to be time. Well, of course the spotlight-present moves in meta-time. If you find ‘meta-time’ suspicious and suspect that ‘movement in meta-time’ needs ‘meta-meta- time’ to be explicated, then you are in the midst of McTaggart’s argument [37]: ‘Tense realism is the tenet that tensed determinations, such as being past, present, or future, are among the ingredients of temporal reality. Famously, McTaggart maintained that the reality of time implies tense realism, but argued that tense realism is incoherent’ [66, p. 281]. The literature on McTaggart’s alleged [34] proof of the ‘unreality of time’ is legion, and we can’t go into it here, but note that his contradiction charge is alive and kicking. These problems of a relatively moving present hint at why the presen- tist cannot take the whole of (space-)time as ontologically prior and then distinguish the present: this would lead right into the contradictory arms of McTaggart! The presentist must think of the present as ontologically prior and of the (space-)time as derivative (Cf. [22]). This does not imply a denial of the reality of the non-present parts of (space-)time, like the presentist must not deny the reality of dinosaurs. Be that as it may, we now have to go on and turn to the question of persistence.

2 Endurance/Perdurance

The endurance/perdurance debate is about the persistence of objects through (space-)time.7 It revolves around the so-called ‘problem of identity through time’ [32, p. 202]: There is an imminent contradiction with Leibniz’ Law for changing objects. To see this, we must first get a grip on the concept ‘change’. A theory of change is necessarily concerned with the persistence of objects or systems through time and thus a criterion for change is that something persists through the change. It is a different situation whether a red ball is replaced with a blue one, or whether a red ball turns blue. So, one benchmark for a theory of change is to distinguish change from exchange.8 Call this ‘continuity’.9 A second benchmark for a theory of change is – which sounds almost trivial – that there needs to be a change. I call this, neutrally, ‘difference’ as it may consist in a something else. For example, for Kant a persisting substance changes by exchanging (‘Wechsel’) its properties, meaning that the change of one entity can consist in the ceasing and beginning of other entities [29, A187 B231]. However, there is more to ‘difference’: The properties which are exchanged must also be incompatible in order for Florian Fischer: Introduction 9

there be change. If something is first red and then square, it does not amount to change.10 As we have sketched out, ‘change needs identity as well as differ- ence’ [41, p. 89]. On the face of it, incompatible properties account for the difference, while the continuity is ensured by the (numerical) identity of the persisting object, but here the problem of persistence has its systematic roots. According to Leibniz’ Law of indiscernibil- ity of identicals11, things which are identical have the same properties: ∀x∀y[x = y → ∀F (F x → F y)]. This is in tension with the very idea of change, according to which one and the same persisting object is supposed to have different, even incompatible, properties.

2.1 The problem of persistence During the rise of the new analytical metaphysics the question of the nature of change was formulated anew by David Lewis. The possible solutions to the problem of change he discusses are, till today, the base for the accounts of persistence. These modern accounts fall into two camps, which have their own ways of dealing with the imminent contradiction with Leibniz’ Law.12

Let us say that something persists iff, somehow or other, it exists at various times; this is the neutral word. Something perdures iff it persists by having different temporal parts, or stages, at different times, though no one part of it is wholly present at more than one time; whereas it endures iff it persists by being wholly present at more than one time [32, p. 202]

Figure 1: Endurantism Figure 2: Perdurantism 10 KRITERION – Journal of Philosophy, 2016, 30(2):3–28

Perdurantism: One possible solution is perdurantism, which de- scribes objects as extended in time. Perduring objects do not only have spatial extension, but also temporal extension. The things we interact with in our everyday life are, according to perdurantism, three- dimensional parts of actually four-dimensional objects. This is a dissolu- tion of the contradiction, as the properties are instantiated by different temporal parts. A ball which is first red and then blue thus changes by having a red and a blue temporal part. The red temporal part is not identical to the blue temporal part and hence the incompatible properties can be instantiated without contradiction. This alleged solution of the problem of change comes with the price that, contrary to our intuitions, objects are four-dimensional space-time entities. ‘We perdure; we are made up of temporal parts, and our temporary intrinsics are properties of these parts, wherein they differ one from another. There is no problem at all about how different things can differ in their intrinsic properties.’ [32, p. 204]. What constitutes continuity for the perdurantist? If there are just different objects instantiating different properties, how can the perduran- tist distinguish change from exchange? The obvious answer is that the objects in question are temporal parts. Thus, there is a whole of which they are part, so that the continuity is supplied by the parthood relation. Ted Sider endorses a variant of perdurantism called the stage view, ‘which identifies continuants with the stages themselves’ [61, p. 84] and not the four-dimensional whole. Here the three dimensional entities, located at their respective moments of time, are called stages and not temporal parts, precisely because they are not parts of a four-dimensional whole. ‘Strictly speaking, the stages [. . . ] are only momentary entities but they are nevertheless said to persist through time by having counterparts at other times’ [4, p. 91]. In contrast to enduring objects the stages are not multi-located. Identity cannot be the continuity-maker, since the ‘counterpart of something [. . . ] is never identical with the thing itself’ [30, p. 45]. The stages do not persist themselves, as they are confided to their respective temporal location but the stage view is nevertheless an account of persistence, since the counterpart relation establishes continuity.13 One could launch a version of the famous Humphrey objection14 against ‘PerdurantismCounterpart’: If the ‘continuants of our everyday ontology’ [61, p. 84] are stages and these only have the temporal properties of their respective points in time, then it is hard to see how I can have any non-present properties. Sider answers to this with a variant of Lewis’ reply to the original Humphrey objection: ‘I do have various tensed Florian Fischer: Introduction 11

properties, such as the property of futurely being not straight. But this is no more a lack of straightness than is being possibly not straight’ [61, p. 85]. Notably, David Lewis, who holds a counterpart theory for cross-world identification, does not posit a counterpart relation between the three- dimensional one-time located perdurantistic property bearers. Without arguments, however, it would be ad hominem to ignore it as a possible unifier. Lewis states: ‘Perdurance, which I favour for the temporal case, is closer to the counterpart theory which I favour for the modal case.’ [32, p. 203] - and, sure, perdurance is closer than endurance, but counterparts would be even closer. Lewis gives us a hint of why he rejects counterpart-perdurantism: ‘counterpart theory concentrates on the parts and ignores the [. . . ] individual composed of them.’ [32, p. 203]. Thus it is questionable whether the inner-world-counterpart account in spirit really is a perdurantistic solution or if it should better be pigeon-holed as an endurantistic account. Let’s have a closer look at endurantism, then. Endurantism: Endurantism respects the every day intuition that objects are three-dimensional entities. Thus, enduring objects are multi- located, as they are located at every time of their existence. The en- durantist takes the, allegedly, more intuitive route of three-dimensional objects, therefore the solution of the perdurantist is not possible for him. Perdurantism can be understood as time-indexing the object. Parallel to this the alleged solution of the endurantist can be depicted as temporally indexing the predicates. Call this view indexicalism. Object o being F at t1 is reinterpreted by the indexicalist as ‘o is Ft1’ or ‘Ft1(o)’. This is not satisfactory, because an object which remains red would always instantiate different properties (redt1, redt2, redt3, . . . ). In light of this criticism adverbialism was invented. Here the copula ‘is’ is amended with a temporal index, or a temporal adverb (hence the name adverbialism) is added to the sentence. So either ‘The ball ist1 red’ or ‘The ball is t1-ly red’. In the debate the name ‘adverbialism’ is used for both versions, but sometimes the temporal-adverb-variant is taken to be the stronger one. Without taking a stance on this, I will name the indexed-copula-variant ‘copularism’. It may turn out that metaphysically there is no difference between the two or that copularism is a subspecies of adverbialism; still, it helps to have the conceptual resources to distinguish them. Lewis depicts endurantism differently: Contrary to the surface appear- ance, intrinsic properties, like shapes are not really properties. They are ‘disguised relations’ [32, p. 204]. Object o stands, say, in the F-relation to time t1 and in the G-relation to time t2. I call this variant ‘relationalism’ 12 KRITERION – Journal of Philosophy, 2016, 30(2):3–28

and add it to our lists of solution candidates for the ‘problem of change’. An additional alleged solution – in fact one that Lewis discusses in [32, p. 203] – is presentism. Presentism is in so much a solution, as there is ever only one moment of time (i. e. the present) and thus never are any incompatible properties instantiated. As Presentism is not on a par with the other options – it’s an account about the nature of time and not the persistence through time – it is hard to depict it in the same fashion as the other alleged solutions.15 One way to presentists represent change is with temporal operators: when the object o is G ‘G(o)’ it was the case that it was F: ‘P F(o)’16, because ‘[w]hile the eternalist can give the truth conditions [. . . ] in terms of quantification over past objects [. . . ] the presentist has to resort to irreducible tensed operators, which she does not take to commit her to the existence of past objects’ [65, p. 2062]. According to Lewis, however, presentism ‘rejects endurance; because it rejects persistence altogether’ [32, p. 203]. Lewis thinks that for a presentist other times are on a par with fictions and that she thus does not give an account of persistence. But, at least according to her own claim, the presentist can distinguish between dinosaurs and unicorns. Only the former have been present, while the latter – sadly – will never have been present. True, ’[o]pponents of presentism have often argued that the presentist has difficulty in accounting for what makes (presently) true past-tensed propositions [. . . ] true in a way that is compatible with her metaphysical view of time and reality’ [65, p. 2047]. So, I merely want to note that Lewis’ argument is a non sequitur: From the presentists denial that the present is on a par with other times, it just doesn’t follow that other times are on a par with fictions. A further possibility is to take the relation of property exemplification (E) as dependent on time: Et1(o, f). This solution takes shapes to be (index-free) properties and accepts the existence of points in time besides the present – just like Lewis’ own solution. It is in no need, however, of temporal parts. It goes back to a proposal by Uwe Meixner [39, p. 95]. Actually Meixner presents a slightly different version with a three-place relation of property exemplification E3 which relates an object, a time 3 and a property: E (o, t1, f). I call this proposals in honour of their – as 3 far as I know – inventor ‘MeixnerismEtn ’ and ‘MeixnerismE ’. For both versions the relation can either be one of second order logic, if its relatum is a property (like ‘F’ or ‘G’) or it can also be formalized in first order logic taking the corresponding singular terminus (‘redness’ corrseponding to the property of ‘being red’ – so, ‘f’ or ‘g’). I take no sides here. Maybe the choice is between logical simplicity and metaphysical Florian Fischer: Introduction 13

dubiousness, maybe it doesn’t matter. Note that Meixner himself takes ‘f’ as a proper name for an universal. Let us sum up: Name Account Continuity Perdurantism F(ot1) ∧ G(ot2) Parthood PerdurantismCounterpart F(st1) ∧ G(st2) Counterpart Indexicalism Ft1(o) ∧ Gt2(o) Multi location Copularism O ist1 F and O ist2 G Multi location Adverbialism O is t1-ly F and O is t2-ly G Multi location Relationism F(o, t1) ∧ G(o, t2) Multi location Presentism PF(o) ∧ G(o) Identity

MeixnerismEtn Et1(o, f) ∧ Et2(o, g) Identity 3 3 MeixnerismE3 E (o, t1, f) ∧ E (o, t2, g) Identity

3 Tense/Tenseless

Now we turn to the controversy about the status of tense.17 This debate started out within the philosophy of language. The old B-theoreticians contested the relevance of the reference to the present moment. They thought linguistic phenomena like tense and aspect and words like ‘now’ or ‘tomorrow’ belong only to the surface structure of sentences and ‘in fashioning canonical notations it is usual to drop tense distinctions.’ [57, p. 170]. The idea is that our messy language obstructs the access to its own semantical or logical structure and deviation from the surface structure helps to clear things up. Thus, the core of the old B-theory is the ‘enterprise of paraphrasing statements so as to isolate their logical structures’ [55, p. 44].

3.1 The old B-theory and the belief in unrestricted translatability Eternalism denies an objective reference to the present moment and thus tensed sentences must have tenseless truth conditions. According to the eternalist the surface structure of a tensed sentence does not correspond to an objective feature in the world. The simple correspondence theory of truth states that a sentence like ‘Paris is the capital of France’ is true just in case the corresponding state of affairs holds true, i. e. Paris really is the capital of France. Likewise ‘It is raining now’ should be true just in case it is raining now.18 An objective reference to the present moment (now) leads to an objective truth value. As the eternalist drops this objective reference to the present moment, she must come up with 14 KRITERION – Journal of Philosophy, 2016, 30(2):3–28

an ersatz truth-maker, otherwise he would have to deny that tensed sentences have a truth value at all. The old B-theoreticians19 believed in translatability: All tensed sen- tences are translatable without a loss of meaning into tenseless sentences. There were different accounts on the market of how this translation should look like in detail. Gottlob Frege [21, p. 297] voted for a date indication analysis: a tensed sentence like (S1) ‘It is raining now’ actually means something along the lines of ‘it is raining at Thursday the 13th May 2014’. Bertrand Russell’s token-reflexive analysis [58, p. 108] in contrast states that the sentence should be translated into ‘It is raining at the point in time that is co-temporal with this utterance’.

3.2 Prior and Perry on now Arthur Prior has famously argued for the irreducibility of tense. Tensed sentences and beliefs are not translatable into tenseless ones, according to Prior. However, they are important for our actions. In [53] Prior’s example is the joy we feel after an important test is over. Sentences we utter at such occasion cannot be understood tenselessly and only tensed beliefs explain our actions and change of emotions (i. e. from stressed to relieved).

One says, e.g. “Thank goodness that’s over!”, and not only is this, when said, quite clear without any date appended, but it says something which it is impossible that any use of a tenseless copula with a date should convey.’ [53, p. 17].

Prior was very explicit about the non-translatability of tensed sen- tences and claimed that the attempt of the old B-theoreticians to substi- tute indexicals like ‘now’ with a date and time indication failed. What causes our joy after the important test is not that the test is over at, say, 4 pm. We would have known that before hand. Also the tenseless relation of earlier/later does not help in this case. It is tenslessly true that 4.15 pm is later than 4 pm (on the same day). Neither the tenseless fact that the test lasts till 4 pm, nor the tenseless fact that 4.15 pm is later than 4 pm explains our joy and even both together are not sufficient. It is the fact that it is 4.15 pm now that gives meaning to the sentence ‘Thank goodness that’s over!’ and that explains our feelings of joy and our actions (celebrating). ‘Thank goodness that’s over!’ has an implicit reference to the present moment and stands for ‘Thank goodness that’s over now!’: Florian Fischer: Introduction 15

It certainly doesn’t mean the same as, e. g. “Thank goodness the date of the conclusion of that thing is Friday, June 15, I954”, even if it be said then. (Nor, for that matter, does it mean ‘Thank goodness the conclusion of that thing is contemporaneous with this utterance”. Why should anyone thank goodness for that?). [53, p. 17] Neither the translation strategy of the old B-theory nor the token reflexive strategy were able to capture the meaning of the tensed sentence “Thank goodness that’s over!” according to Prior. Prior was chiefly concerned with matters of time and thus his paper focused on the indexical ‘now’, which is also our topic here. John Perry made a more general claim concerning indexicals. Perry’s 1979 paper [50] featured three examples of which I would like to introduce the one starring the tardy professor: [A] professor, who desires to attend the department meeting on time, and believes correctly that it begins at noon, sits motionless in his office at that time. Suddenly he begins to move. What explains his action? A change in belief. He believed all along that the department meeting starts at noon; he came to believe, as he would have put it, that it starts now.[50, p. 4] Perry called beliefs which contain indexicals like ‘I’, ‘here’ and ‘now’ locating beliefs. Locating beliefs are necessary for actions, since the corresponding tenseless beliefs do not explain the sudden movement of the tardy professor. Perry’s conclusion was that we believe the same thing, but in different ways: As time passes, I go from the state corresponding to ‘The meeting will begin’ to the one corresponding to ‘The meeting is beginning’ and finally to ‘The meeting has begun’. All along I believe of noon that it is when the meeting begins. But I believe it in different ways. And to these different ways of believing the same thing, different actions are appropriate: preparation, movement, apology. [50, p. 19] Since we are not concerned with beliefs here the details of Perry’s account do not matter. We can, however, state that Perry puts forward a strong argument against the translatability of tensed sentences into tenseless ones. After Prior and Perry it has generally been accepted that tensed sentences and beliefs are necessary for our actions and that they cannot be translated without a loss of meaning into tenseless ones. 16 KRITERION – Journal of Philosophy, 2016, 30(2):3–28

3.3 The New Tenseless Theory of Time

The New Tenseless Theory of Time (NTT) differs from the old B-theories by acknowledging the irreducibility of tensed sentences. So even B- theories accept that there are sentences whose truth values depend on time. The NTT thus incorporates more dynamics, as one would expect. But still the NTT is an eternalistic theory, i. e. every point in time is ontologically on a par and there is no objective reference to the present moment. So, how does a non-tensed world view go alongside with irreducible tensed sentences? The NTT exploits the fact that the surface structure of a sentence can deviate from the structure of the truth-maker of this sentence.20 According to the old B-theory, tensed sentences could, or even should, be translated into tenseless ones, but after Prior and Perry this thesis must be dropped. ‘[R]ecent defenders of the tenseless view have come to embrace the thesis that tensed sentences cannot be translated by tenseless ones without loss of meaning.’ [48, p. 58]. The new B-theoreticians still call their view tenseless, but this tenselessness now concerns the structure of the world.21 With the NTT the link between metaphysics and language became much tighter. One can only truly be called a B-theoretician nowadays if one holds a tenseless world view.22 ‘Tensed discourse is indeed necessary for timely action, but tensed facts are not’ [48, p. 58]. Tensed beliefs can vary in their truth value but tenseless ones do not change their truth value.23 Tenseless truth conditions can be given for every tensed belief, according to the NTT. Tensed sentences may have different truth values and thus must have different truth conditions. This is at odds with the plausible claim that any sentence, and thus also a tensed sentence, has the same meaning in every context. The champion of the NTT, David Hugh Mellor himself, agrees that ‘truth conditions must surely supervene on meanings’ [41, p. 6]. A sentence like ‘it is raining now’ has the same meaning always and everywhere. But it seems that according to the NTT the sentence must change its truth conditions, since it must be made true by different tenseless facts at every time. Only a tensed theoretician can maintain that ‘it is raining now’ has the same tensed truth conditions in every context, namely that it is true if the tensed fact that it is raining now occurs. At first glance it seemed that the B-theoretician could just posit a different reduction strategy to acknowledge Prior’s and Perry’s arguments. Instead of translating the tensed sentence she claims that there are Florian Fischer: Introduction 17

different tenseless truth conditions for every token of the sentence. As we have seen, however, this contradicts the claim that a sentence has the same meaning at every time and that truth conditions supervene on meaning. Mellor’s NTT from Real Time II is supposed to solve this problem. Mellor claims that a token of a tensed sentence is tenselessly true and has only one truth condition. This acknowledges the variability of the truth value on the type level. If a token of a tensed sentence is true, then it is a-temporally true, made true by a tenseless fact. With this distinction between type and token in place, Mellor can account for the stable meaning of a tensed sentence. In his first attempt, Real Time [40], Mellor understood the meaning of a tensed sentence as a function from utterances to truth conditions. Due to strong critique [48] he changed his position and in Real Time II [41] he understands the meaning of a tensed sentence as a function from ‘B-times to B-truth conditions’ [41, p. 59]. Meaning is concerned with sentence types, according to Mellor. Tenseless sentences have constant functions as their meaning, while the functions of tensed sentences can be non-constant. The possibility of variation in the truth conditions (the co-domain of the function) allows for the variability in the truth value.24

4 Packages

We have introduced the dynamic/static distinction in the context of the presentism/eternalism debate (sec.1). A quick reminder: a view is ‘dynamic’ iff existence is time relative, otherwise ‘static’. In section3 we have introduced the distinction between A- and B-theory.25 Combining both leads to four time-reality combinations:

time reality 1. B-theory static 2. B-theory dynamic 3. A-theory static 4. A-theory dynamic Classical eternalism is a static B-theory and classical presentism is a dynamic A-theory. The moving spotlight theory states that existence is not time relative, but the present is nevertheless ontologically distin- guished and thus it’s a static A-theory, while the ‘growing block’ theory is – at least allegedly – a dynamic B-theory. Presentists are virtually always endurantists. Many may even think 18 KRITERION – Journal of Philosophy, 2016, 30(2):3–28

that presentism and perdurantism are inconsistent. At least Sider holds that ‘no contemporary philosopher defends the combination of presentism and perdurance.’ [59, p. 68]. Contrary to that, Berit Brogaard does not only think that presentism and perdurantism are compatible, but develops a Presentist Four-Dimensionalism in [7]. Jorgen Hansen builds his Stage View Presentism on this which he claims to be ‘an appealing alternative for presentists who remain impartial to both the endurantist and the worm theories of persistence’ [26]. In the debate about persistence, eternalism is (often) presupposed. This hints at a prima facie compatibility of both endurantism and per- durantism with eternalism. This is plausible. Given eternalism the disagreement is about what the world-line represents: perdurantist think this is the whole object, whereas endurantists believe the world-line to represent the history of the object. Figure1 shows the object O e multilocated, while in figure2 the object O p is the whole world-line and at each point in space-time there is ‘only’ a part (like TP1, TP2, . . . ). So, perdurantism seems to come pack and parcel with eternalism: ‘It is certainly true that most if not all four-dimensionalists presuppose eternalism.’ [59, p. 71]. The endurantist is, at least prima facie, free to choose, however. The combination of eternalism and perdurantism is called ‘manifold theory’ [59, p. 69]. The deal might be even more inclusive for the perdurantist, as it may include the tenseless theory (see section 3.3). The other way around is quite inclusive as well: ‘Reductionists about tense, then, are invariably eternalists.’ [59, p. 14]. So, If you are a de- tenser, you almost have to be an eternalist. Most probably you are then also a perdurantist, but this is not necessary: You may be a de-tensing, eternalistic endurantist – for whatever reason. Arthur Prior compiled the other ‘one-click-bundle’ available on the market: He advocates the combination of tensed theory, endurantism and presentism. Besides arguing for presentism [59, p. 18], Prior states: ‘it is not the case that one part of me was a boy in New Zealand while another part of me is a man in England; it is I who was that boy, and I - the same I - who am the man’ [51, p.183] - hence endurantism. He further believes that ‘It is raining’ actually means ‘It is raining now’ [46, p. 23]. There seems to be a tendency here: On the one hand, the perduran- tism/tenseless theory/eternalism package fits well and is often bought in one. Endurantism, tensed theory, and presentism, on the other hand, are not so tightly interwoven. The mentioned packages offer only a glimpse Florian Fischer: Introduction 19

at the various links between the debates. So, even if the three debates – about the nature of time, the persistence through time, and the reference to the present moment – start out independently, a satisfactory account in the philosophy of time may very well need to take all three fields26 and their prerequisites into consideration.27

Acknowledgements

I would like to thank the audience at the 2016 Time and Change workshop in Bonn, where I presented the persistence part of this introduction, for a useful and at the same time pleasant discussion. The way I see the philosophy of time – which might be in some areas non-standard; hence ‘A slightly opinionated introduction’ – has developed over the last couple of years. I cannot list all the people with which I had talked about the topic during this period, but you know who you are (you are all self- identical). I would like to thank the members of the SPoT (at least those, with which I am not self-identical) for the incredible time. Especially I want to thank Dan Deasy, Sonja Deppe, Jesse Mulder, Thorben Petersen, Alastair Wilson and Pamela Zinn who have read this text and helped to improve it a great deal.

Notes

1 Objects endure, if they persist by being wholly present. ‘Thus to say that Socrates persists is just to say that the whole of him is present at each times of existence.’ [8, p. 883]. Numerically one object can be completely present at t1 and t2. When it is present at t1, however, it can neither be present at t2 nor can a part of it be present at t2. The worldline of an enduring object represents its history through space and time (or space-time). This suffices as a rough characterization but it is quite controversial how to capture ‘wholly present’ exactly. ‘[W]hat is it for something to be “wholly present” at a time? It’s surprisingly difficult to say’ [12, p. 318]. 2 Kit Fine distinguishes between ontic and factive presentism: ‘Ontic presentism is an ontological position; it is a view about what there is. Factive presentism, on the other hand, is a metaphysical rather than an ontological position; it is view about how things are, quite apart from what there is’ [16, p. 299]. Ontic presentism can be associated with what I will call the occupants-formulation of presentism. The, in my terminology, time-formulation does not correspond to Fine’s factive presentism, however. The time-formulation and the occupants-formulation may turn out to be equivalent, while Fine argues for a substantial difference between factive and ontic presentism, as, for example, ‘[i]t is readily possible for a factive presentist not to be an ontic presentist’ [16, p. 299]. Fine’s factive presentism is compatible with ontic eternalism, as, as Giuliano Torrengo puts it, the ‘presentist here is exploiting the metaphysical view of the A-theory of time to solve the 20 KRITERION – Journal of Philosophy, 2016, 30(2):3–28

contradiction, rather than her ontology restricted to presently existing entities’ [64, p. 255]. 3 It is important to speak of space-time rather then only time, as it is sometimes argued that modern physical theories, especially the SRT and ART, supply a posteriori arguments for the philosophy of time. See the contribution of Cord Friebe [22] in this volume, for an argument – completely contrary of what is otherwise assumed – that only presentism can cope with the peculiarities of the ART, namely the closed timelike curves of, so-called, G¨odeluniverses. 4 Presentism, it is argued, is either trivial or clearly false (Cf. [44, p. 214–216]). The ‘exists’ in the presentist’s claim that ‘only what is present exists’, must be understood either tensed or tenseless, according to the critics. It is trivially true that only present entities exist now, while it is clearly false that only present things exist simpliciter (just think about Socrates). Harold Noonan answers to this charge: ‘Likewise, I suggest, it is neither trivially true nor obviously false that everything (simpliciter) which is temporally locatable is presently existent.’ [47]. 5 Perhaps it is even too much of a concession towards presentism to speak of ‘past’ and ‘future’ entities. ‘Future’ and ‘past’ only make sense in reference to the present. Maybe the hardcore eternalist should say that all times/entities are ontologically on a par. He should stick with the tenseless relations of ‘earlier’ and ‘later’ and completely shun talk of ‘present’, ‘future’ and ‘past’. 6 See [22] in this volume for a discussion of objectivity of presentism in the ART. 7 Also here talk of space-time instead of time might be important, as it is some- times argued that perdurantism has an advantage over endurantism regarding compatibility with the SRT (e. g. [2] and [3]). There Yuri Balashov argues that the endurantist, and only she, is committed to claims containing tensed deter- minations, which are allegedly incompatible with the SRT. See my [20] for the attempt of a rebuttal of Balashov’s originally asymmetry thesis. 8 Arguably already Aristotle has distinguished change form exchange, as he clearly distinguishes change from the processes of coming to be and passing away, accord- ing to Thomas Buchheim [9, p. XVII]. Coming to be and passing away are not just changes of some always existing entity 9 I have chosen the term ‘continuity’ in order to not pre-decide the debate. The alleged unifier might be ‘identity’ or ‘parthood’ or ‘multilocation’ or something else. 10 Change needs at least continuity and difference. See [19] for a longer introduction of alleged characteristics of change. There I list: difference, identity, incompatibility, irreversibility and succession. 11 ‘Identity looms large in Leibniz’s philosophy. He is responsible for articulating two principles that, he claims, are constitutive of identity. The first, more controversial, of these, called the identity of indiscernibles, says that qualitative indiscernibility implies identity. The second, often referred to as Leibniz’s Law or the Indiscernibil- ity of Identicals, says that identity implies qualitative indiscernibility. According to Leibniz’s Law, if a is identical with b, every quality of a will be a quality of b.’ [24]. 12 The contenders of the modern debate seem to be content with a removal of the logical contradiction with Leibniz’ law. This, however, is not a solution of the problem of change, but merely a precondition: Every theory which doesn’t address the lurking contradiction is a non-starter. (As argued in [18].) Florian Fischer: Introduction 21

13 Uwe Meixner [38] also presents a view – which he does not endorse – with a temporal counterpart relation, called supereternalism. Meixner claims that with it ‘one can have change, although no object whatever changes in the sense that it ever has any other properties appropriate for change than those it has now.’ [38, p. 432]. Both views seem quite similar to me. 14 For David Lewis your counterparts ‘are not really you. For each of them is in his own world, and only you are here in the actual world. Indeed we might say, speaking casually, that your counterparts are you in other worlds that they and you are the same; but this sameness is no more a literal identity than the sameness between you today and you tomorrow. It would be better to say that your counterparts are men you would have been, had the world been otherwise’ [31, p. 114–115]. Kripke finds this absurd and has launched his, now famous, Humphrey objection against it: ‘Thus, if we say ‘Humphrey might have won the election (if only he had done such-and-such)’, we are not talking about something that might have happened to Humphrey but to someone else, a ‘counterpart’. Probably, however, Humphrey could not care less whether someone else, no matter how much resembling him, would have been victorious in another possible world [30, p. 45]. 15 See the contribution of Jesse Mulder [45] in this volume, for an attempt of ‘Defining Original Presentism’. There Mulder agrees with Jonathan Tallard [62], that eternalism and presentism need to be differentiated on a much more fundamental level, then usually attempted. 16 See e. g. [25, p. 50] for an introduction to temporal logic. See [46] for a detailed reconstruction and further development of Prior’s tense logic. 17 There are several related debates. Giuliano Torrengo offers the following, helpful, classification: ‘The distinction between A-theory and B-theory is metaphysical. According to the A-theory, the passage of time is real, and, thus, tense determi- nations (such as being present, past, and future) are genuine features of reality. According to the B-theory tense determinations are reducible to relations between a perceiver and a position in time. The distinction between the presentist and the eternalist is ontological. According to the presentist, in our most unrestricted domain of quantification we find only presently existing entities, whereas according to the eternalist also past and future entities exist. The distinction between the serious tenser and the de-tenser is semantic. According to the serious tenser tensed sentences express tensed propositions, namely propositions that are temporally undetermined (their truth-value being possibly variable through time), whereas according to the de-tenser tensed sentences express tenseless propositions, namely propositions that are temporally determined (bearing a determined truth-value re- gardless of time)’ [64, p. 253]. However, the terminology is far from homogeneous in this area of philosophy. So, in this introduction I will switch freely between the terms ‘tensed theory’, ‘tensers’, and ‘A-theory’ (as well as their counterparts) if no a specific linguistic or ontological reading is necessary. Otherwise I make this explicit. 18 [28] provides an overview of the semantics of the word ‘now’ in ordinary language and discusses formal systems, drawing heavily on the work of Arthur Prior [52]. 19 ‘Following McTaggart (1908), tensed and tenseless temporal judgments are often called A-judgments and B-judgments, respectively. The concepts now, was, will, and the like are called A-concepts, whereas the concepts before, after, and related concepts are called B-concepts’ [59, p. 12]. 22 KRITERION – Journal of Philosophy, 2016, 30(2):3–28

20 We can have, for example, definite truth values for disjunctive sentences, without positing disjunctive facts in the world. 21 Sonja Deppe [13], however, questions the claim of the tenseless theorists that the relational structure of earlier/later is a metaphysical feature of time itself. With the help of Henry Bergson – a philosopher who is, sadly and wrongly, under- represented in the contemporary debate – she tries to show that this relational structure is part of our intellectual engagement with temporal phenomena instead. 22 See my paper [17] in this volume. There I argue that the NTT may be too metaphysical for some philosophers. Arguably Rudolf Carnap belongs in the camp of the old B-theory, but cannot make the transition to the NTT, because this contradicts his inter-translatability thesis and metaphysical neutrality thesis. 23 It is sometimes stated that tenseless sentences are always true if they are sometimes true, but this is only one half of the story. There are two ways to negate the variation in truth value. A sentence can either always have a truth value (omni- temporal) or not in a timely sense at all (a-temporal). ‘5 is a prime number’ is an example for an a-temporal truth [23, p. 60]. This sentence is a-temporal because it is meaningless to ask ‘When is 5 a prime number?’. A-temporal sentences do not vary in their truth value because conceptually they simply cannot. Omni-temporal sentences could vary, because they are located in time but, for some reason or other, just do not. 24 One possible critique is that this approach might not work if nature is too complex. If time and space are continua, as for example Aristotle [1, ch. 5] has famously argued, then there are at least uncountably many items in the domain of the function. I don’t want to claim, however, that this attack is successful or promising, I’m merely mentioning it. 25 See [45, p. 14] in this volume for a more ‘Fine’-grained characterisation, where Jesse Mulder, following Kit Fine, distinguishes three versions of A-theory. 26 Of course, there might be even more debates which have to be taken into account, as the epistemology of time or the history of philosophy. See the contribution of Pamela Zinn [68] in this volume, which analyses Lucretius’ account of time in his De rerum natura, focusing precisely not only on the nature of time but also on its perception. 27 If you disagree with something, dear reader, then I’m satisfied. I would be glad if you could prove me wrong and present your work on one of our SPoT-meetings: http://s-p-o-t.weebly.com - please feel welcome to!

Florian Fischer University of Bonn Institut f¨urPhilosophie Am Hof 3 - 5 53113 Bonn Florian Fischer: Introduction 23

References

[1] Aristoteles. Physik. Ed. by H. G. Zekl. Vol. V-VIII. Hamburg: Meiner, 1988. [2] Yuri Balashov. “Enduring and Perduring Objects in Minkowski Space-Time”. In: Philosophical Studies 99 (2000), pp. 129–166. [3] Yuri Balashov. “Special Relativity, Coexistence and Temporal Parts: A Reply to Gilmore”. In: Philosophical Studies 125 (2005), pp. 1–40. [4] Jiri Benovsky. Persistence Through Time and Across Possible Worlds. Ontos Verlag, 2006. [5] John Bigelow. “Presentism and Properties”. In: Philosophical Per- spectives 10.Metaphysics (1996), pp. 35–52. [6] Andrea Bottani, Massimiliano Carrara, and Daniele Giaretta. In- dividuals, Essence, and Identity. Themes of Analytic Metaphysics. Kluwer, 2002. [7] Berit Brogaard. “Presentist Four-Dimensionalism”. In: The Monist 83.3 (2000), pp. 341–356. [8] Jeffrey E. Brower. “Aristotelian Endurantism: A New Solution to the Problem of Temporary Intrinsics”. In: Mind 119.476 (2010), pp. 883–905. [9] Thomas Buchheim, ed. Uber¨ Werden und Vergehen - De generatione er corruptione. Hamburg: Meiner, 2011. [10] Craig Callender. “Shedding Light on Time”. In: Philosophy of Science 67.3 (2000), p. 599. [11] Thomas M. Crisp. “Presentism”. In: The Oxford Handbook of Metaphysics. Ed. by Michael J. Loux and Dean W. Zimmerman. Oxford University Press, 2003. [12] Thomas M. Crisp and Donald P. Smith. “’Wholly Present’ Defined”. In: Philosophy and Phenomenological Research 71.2 (2005), pp. 318– 344. [13] Sonja Deppe. “The Mind-Dependence of the Relational Structure of Time (or: What Henri Bergson Would Say to B-theorists)”. In: New Developments in Philosophy of Time. Ed. by Florian Fischer. Kriterion – Journal of Philosophy, 2016. 24 KRITERION – Journal of Philosophy, 2016, 30(2):3–28

[14] Michael A. E. Dummett. “The Reality of the Past”. In: Truth and Other Enigmas. Harvard University Press, 1978. [15] Michael A. E. Dummett. Truth and Other Enigmas. Harvard Uni- versity Press, 1978. [16] Kit Fine. “Tense and Reality”. In: Modality and Tense. Oxford: Oxford University Press, 2006. [17] Florian Fischer. “Carnap’s Logic of Science and Reference to the Present Moment”. In: New Developments in Philosophy of Time. Ed. by Florian Fischer. Kriterion – Journal of Philosophy, 2016. [18] Florian Fischer. “Das Problem der Persistenz”. In: Proceedings of ‘XXII. Kongress der Deutschen Gesellschaft f¨urPhilosophie’. 2011. [19] Florian Fischer. “Limit Deciding Dispositions”. In: Vivarium ((forthcoming)). [20] Florian Fischer. “On the Asymmetry of Endurantistic and Perduran- tistic Coexistence in Special Relativity”. In: Philosophia Naturalis 49.1 (2012), pp. 43–61. [21] Gottlob Frege. “The Thought: A Logical Inquiry”. In: Mind 65.256 (1956). Ed. by Peter Geach, pp. 289–311. [22] Cord Friebe. “Time Order, Time Direction, and the Presentist’s View on Spacetime”. In: New Developments in Philosophy of Time. Ed. by Florian Fischer. Kriterion – Journal of Philosophy, 2016. [23] Cord Friebe. Zeit – Wirklichkeit – Persistenz. Eine pr¨asentistische Deutung der Raumzeit. Paderborn: Mentis, 2012. [24] Andre Gallois. “Identity Over Time”. In: The Stanford Encyclopedia of Philosophy. Ed. by Edward N. Zalta. Winter 2015. 2015. [25] James W. Garson. Modal Logic for Philosophers. Cambridge Uni- versity Press, 2006. [26] Jorgen Hansen. “A Case for Stage View Presentism”. http://philpapers.org/archive/HANACF. [27] Aleksandar Jokic and Quentin Smith, eds. Time, Tense, and Ref- erence. A Bradford Book, 2003. [28] Hans Kamp. “Formal Properties of ‘Now’”. In: Theoria 37.3 (1971), pp. 227–273. [29] Immanuel Kant. Critique of Pure Reason. Ed. by P. Guyer and A. Wood. The Cambridge Edition of the Works of Immanuel Kant. Cambridge: Cambridge University Press, 1998. Florian Fischer: Introduction 25

[30] Saul A. Kripke. Naming and Necessity. Harvard University Press, 1980. [31] David K. Lewis. “Counterpart Theory and Quantified Modal Logic”. In: Journal of Philosophy 65.5 (1968), pp. 113–126. [32] David K. Lewis. On the Plurality of Worlds. Blackwell Publishers, 1986. [33] Michael J. Loux and Dean W. Zimmerman. The Oxford Handbook of Metaphysics. Oxford University Press, 2003. [34] E. J. Lowe. “McTaggart’s Paradox Revisited”. In: Mind 101.402 (1992), pp. 323–326. [35] Ned Markosian. “A Defence of Presentism”. In: Oxford Studies in Metaphysics 1.3 (2004), pp. 47–82. [36] Ned Markosian. “Time”. In: The Stanford Encyclopedia of Philoso- phy. Ed. by Edward N. Zalta. Spring 2014. 2014. [37] J. Ellis McTaggart. “The Unreality of Time”. In: Mind 17.68 (1908), pp. 457–474. [38] Uwe Meixner. “Change and Change-Ersatz”. In: Individuals, Essence, and Identity. Themes of Analytic Metaphysics. Ed. by An- drea Bottani, Massimiliano Carrara, and Daniele Giaretta. Kluwer, 2002. [39] Uwe Meixner. David Lewis. nachGedacht. Paderborn: Mentis, 2006. [40] David Hugh Mellor. Real Time. Cambridge: Cambridge University Press, 1985. [41] David Hugh Mellor. Real Time II. London: Routledge, 1998. [42] Trenton Merricks. “Goodby Growing Block”. In: Oxford Studies in Metaphysics 2 (2006). [43] Trenton Merricks. “Persistence, Parts, and Presentism”. In: Noˆus 33.3 (1999), pp. 421–438. [44] Ulrich Meyer. “The Presentist’s Dilemma”. In: Philosophical Studies 122.3 (2005), pp. 213–225. [45] Jesse M. Mulder. “Defining Original Presentism”. In: New Devel- opments in Philosophy of Time. Ed. by Florian Fischer. Kriterion – Journal of Philosophy, 2016. [46] Thomas M¨uller. Arthur Priors Zeitlogik: Eine problemorientierte Darstellung. Paderborn: Mentis, 2002. 26 KRITERION – Journal of Philosophy, 2016, 30(2):3–28

[47] Harold Noonan. “Presentism and Eternalism”. In: Erkenntnis 78.1 (2013), pp. 219–227. [48] Nathan L. Oaklander and Quentin Smith, eds. The New Theory of Time. New Haven: Yale University Press, 1994. [49] Robert J. Oppenheimer. Science and the Common Understanding. New York: Simon & Schuster, 1953. [50] John Perry. “The Problem of the Essential Indexical”. In: Nous (1979), pp. 3–21. [51] A. N. Prior. “Time, Existence and Identity”. In: Proceedings of the Aristotelian Society 66 (1965), pp. 183–192. [52] Arthur Prior. “‘Now’”. In: Noˆus 2 (1968), pp. 101–119. [53] Arthur N. Prior. “Thank Goodness That’s Over”. In: Philosophy 20 (1959), p. 17. [54] Willard Van Orman Quine. From a Logical Point of View. Harvard University Press, 1953. [55] Willard Van Orman Quine. Methods of Logic. New York: Holt, Rinehart and Winston, 1950. [56] Willard Van Orman Quine. “On What There Is”. In: The Review of Metaphysics 2.5 (Sept. 1948), pp. 21–38. [57] Willard Van Orman Quine. Word & Object. The MIT Press, 1960. [58] Bertrand Russell. An Inquiry into Meaning and Truth. London: Allen & Unwin, 1950. [59] Theodore Sider. Four Dimensionalism. Oxford: Oxford University Press, 2002. [60] Theodore Sider. “Presentism and Ontological Commitment”. In: Journal of Philosophy 96 (1999), pp. 325–347. [61] Theodore Sider. “The Stage View and Temporary Intrinsics”. In: Analysis 60.1 (2000), pp. 84–88. [62] Jonathan Charles Tallant. “Defining Existence Presentism”. In: Erkenntnis 79.3 (2014), pp. 479–501. [63] Giuliano Torrengo. “Ostrich Presentism”. In: Philosophical Studies 170.2 (2014), pp. 255–276. [64] Giuliano Torrengo. “Tenseless Time Vs. Tensed Truthmakers”. In: Proceedings of “Fostering the Ontological Turn, Gustav Bergmann 1906-1087”. Frankfurt: Ontos Verlag, 2008, pp. 253–260. Florian Fischer: Introduction 27

[65] Giuliano Torrengo. “The Grounding Problem and Presentist Ex- planations”. In: Synthese 190.12 (2013), pp. 2047–2063. [66] Giuliano Torrengo. “Time, Context, and Cross-Temporal Claims”. In: Philosophia 38.2 (2010), pp. 281–296. [67] Dean Wallace Zimmerman. “Temporary Intrinsics and Presentism”. In: Metaphysics: The Big Questions. Ed. by Peter van Inwagen and Dean Wallace Zimmerman. Wiley-Blackwell, 1998, pp. 206–219. [68] Pamela Zinn. “Lucretius On Time and Its Perception”. In: New De- velopments in Philosophy of Time. Ed. by Florian Fischer. Kriterion – Journal of Philosophy, 2016.

Defining Original Presentism

Jesse M. Mulder

Abstract It is surprisingly hard to define presentism. Traditional defini- tions of the view, in terms of tensed existence statements, have turned out not to to be capable of convincingly distinguishing presentism from eternalism. Picking up on a recent proposal by Tallant, I suggest that we need to locate the break between eternalism and presentism on a much more fundamental level. The problem is that presentists have tried to express their view within a framework that is inherently eternalist. I call that framework the Fregean nexus, as it is defined by Frege’s atemporal understanding of predication. In particular, I show that the tense-logical understanding of tense which is treated as common ground in the debate rests on this very same Fregean nexus, and is thus inadequate for a proper definition of presentism. I contrast the Fregean nexus with what I call the original temporal nexus, which is based on an alternative, inherently temporal form of predication. Finally, I propose to define presentism in terms of the original temporal nexus, yielding original presentism. According to original presentism, temporal propositions are distinguished from atemporal ones not by aspects of their content, as they are on views based on the Fregean nexus, but by their form—in particular, by their form of predication.

Keywords: presentism, A-theory, time, tense, predication, ex- istence

Introduction

Presentists uniformly reject any view on which past and future things exist just as much as present things do. Yet it is surprisingly hard to formulate, in a satisfactory manner, what their positive view is. Indeed, a small industry has recently developed over the question how best to define presentism. The issue has become all the more urgent through,

Kriterion – Journal of Philosophy, 2016, 30(2): 29–60. http://www.kriterion-journal-of-philosophy.org c 2016 The author 30 KRITERION – Journal of Philosophy, 2016, 30(2): 29–60 amongst other things, charges of insubstantiality [5, 15, 16, 36], and through the infamous truthmaker arguments [3,4,6,7,8, 10, 13, 19, 29, 39, 41, 42]. At bottom, the problem that the presentist faces is that the seemingly straightforward ways of defining the view—in terms of a suitable, tensed existence claim, that is—turn out to be either trivially true (so that they are acceptable to everyone, including eternalists) or trivially false (so that they are acceptable to nobody, including presen- tists). Picking up on a recent suggestion by Jonathan Tallant [39], who is in turn inspired by Trenton Merricks [29], I will propose a fresh look at the problem of defining presentism, that leads to a new definition (of sorts). My hypothesis is that whereas eternalism meshes nicely with standard logical formalisms, including tense logic, presentism in fact does not. If that is right, the problems that plague definers of presentism result simply from the fact that they are trying to formulate their view within a framework that is inherently eternalist. For reasons to be explored, I call that framework the Fregean nexus. It is pointless to try to formulate, within that framework, a coher- ent, non-trivial statement on which presentists and eternalists can agree to disagree. Instead, the presentist should step back and develop her views against the background of an alternative framework that doesn’t exclude presentism from the start. In this paper, I argue that there is such a framework, and, moreover, that this alternative framework en- tails presentism. That is to say, the alternative framework is as hostile to eternalism as the Fregean nexus is to presentism. I call this alterna- tive framework the original temporal nexus. It is inspired by Sebastian R¨odl’shighly original work on ‘categories of the temporal’ [34]. The key to this alternative is a different form of predication—different, that is, from the Fregean form of predication that constitutes the core of the Fregean nexus, and thus underlies standard logical formalisms (again, including tense logic). I sketch that alternative form of predication, and the logical categories to which it gives rise. Presentism can then be defined as the view that the original temporal nexus is ineliminable and irreducible. In other words, the difference between eternalism and presentism turns out to be a formal one (in my sense of “formal”—see §2). I start with a brief review of recent attempts at a definition of pre- sentism in §1, then move on to introduce the notion of forms of pred- ication, including a characterization of the two mentioned frameworks, the Fregean nexus and the original temporal nexus, in §2. It transpires Jesse M. Mulder: Defining Original Presentism 31 from these two opening sections that we need to take a thorough look at the understanding of tense that stands in the background of the debate on definitions of presentism. So, in §3, I scrutinize that understanding and show what is wrong with it: it rests on the Fregean nexus. In the final section, §4, I propose my own definition, in terms of the original temporal nexus.

1 Defining Presentism

Eternalists say that everything past, present, and future exists. Presen- tists deny this: only present things exist. They say that past things are no more, while future things are not yet.1 Since these claims look like existence claims, it is natural to start formalizing them using the existential quantifier, in order to arrive at a substantial existence claim that eternalists and presentists unequivocally disagree on. Further progress in the debate between eternalists and presentists can then be made by spelling out exactly what it takes to endorse that claim or its negation. Or so it is thought. Before we assess this strategy, three preliminary remarks on termi- nology are in order. First, I adopt a broad conception of A-theory—any view on which tense is metaphysically fundamental (in some sense) qual- ifies as a version of A-theory in my sense.2 Second, I take presentism to be a version of A-theory; the existence claim that presentists are looking for to identify their position will thus have to be read tensedly. And third, I conceive of presentism’s opposite, eternalism, rather broadly as well—encompassing both the more orthodox, B-theoretic versions of the view and also A-theoretic versions such as moving spotlight theory.3 Now, Meyer [30] challenges the presentist as follows.4 He takes the following proposed definition of presentism as his starting point:

P Nothing exists that is not present. [30, p.213]5

P is ambiguous in its tense, for “exists” can be read in two ways. Dis- ambiguation yields the following two alternatives:

P1 Nothing exists now that is not present.

P2 Nothing exists temporally that is not present. [30, p.214]

P1 is trivially true, and is thus of no help to the presentist. The alter- native is to render “exists” as temporally general: has existed, exists, or will exist. That is what P2 expresses, which is clearly absurd: Julius 32 KRITERION – Journal of Philosophy, 2016, 30(2): 29–60

Caesar, for instance, existed, but is not present. Thus, presentism is either trivial or absurd.6 If these were the only options for the presentist, the view would indeed be doomed. For P1, being trivial, fails to capture a distinctive position, while P2 amounts to the absurd thesis that reality is just one snap-shot: it is what we get if we take the eternalist’s time line and simply erase everything except for the present moment. It seems that Lewis thought of presentism along the lines of P2—hence his dismissive observation that presentism denies time altogether (see [23, p.204] and [24, p.2]). Serious presentists will want to say that this is a straw man— let us call the straw man position ‘negative presentism’. They are under pressure to define their view differently. Crisp develops an alternative reading of P2 which is carefully crafted so as to be solve this dilemma [11]. In particular, he thinks counterex- amples to P2, like “Julius Caesar existed but is not present”, can be rejected if we take care to properly delineate the domain over which the temporally general quantifier in P2, “exists temporally”, ranges.7 He urges us to distinguish between a de dicto and a de re reading of such alleged counterexamples to P2, which he renders as follows (where tα denotes the present time):

RE1 WAS(for some x, x is Julius Caesar and x will not exist in tα)

RE2 For some x, x was Julius Caesar and x is no longer present [11, p.18; example adapted]

The point, then, is that RE1 is obviously true but doesn’t provide the kind of counterexample that turns P2 into a falsehood, whereas RE2 is not obviously true (or false) at all. It seems that the eternalist has to accept RE2, while the presentist denies it. The key to Crisp’s definition is a dynamic conception of the domain of quantification: it used to contain Julius Caesar, but doesn’t anymore.8 If we think of the domain as representing reality, it appears that we do get a presentist picture: only present things exist. Unfortunately, as Tallant shows, Crisp’s attempt still falls prey to a Meyer-style objection [39]. For what is the tense of the quantifier in RE2? Following Meyer, the options Tallant presents are in terms of present existence (∃n: exists now) and temporal existence (∃t: existed, exists now, or will exist):

∗ RE2a ∃n(x was Julius Caesar and ∼PRES x) Jesse M. Mulder: Defining Original Presentism 33

∗ RE2b ∃t(x was Julius Caesar and ∼PRES x) [39, p.481; example adapted]

It seems that the presentist has to be in agreement with the eternalist ∗ ∗ on both RE2a and RE2b: the first is trivially false, while the negation of the second is, again, untenable: Julius Caesar did exist, so the quantifier 9 ∃t does range over him. Again, if these are the only options for the presentist, the view is doomed as it has to choose between a triviality on the one hand and the absurdity of negative presentism on the other. But Tallant has more to say. His aim, like mine, is to provide a novel definition of presentism. His proposal is, as we will see shortly, to switch from existence claims to a claim about existence. He takes his cue from the following passages by Merricks:

Presentists and eternalists alike say that those things that exist at the present time really do exist and, moreover, that properties had at the present time really are had. Thus one might think, whilst presentism and eternalism part ways with respect to other times, they agree about the nature of the present time, and, relatedly, agree about what it is to exist (and have properties) at the present time. But they do not agree about these things. Indeed, their differences with re- spect to the nature of, and existence at, the present time are as important as their differences with respect to the past and future. [29, p.123] Since they do not believe in a region called the ‘present time’, presentists cannot reduce existing at the present time to be- ing located at that region. I think presentists should, in- stead, say that existing at the present time just is existing. [29, p.125]10

Tallant comments on these passages as follows:

It seems right that presentism ought to be understood, not merely as a thesis concerning the number of times that exist, but also as a thesis with a commitment to the nature of those times. [39, p.493]

This sounds promising. Perhaps the presentist only seems to be stuck between a triviality and the absurdity of negative presentism as long as she assumes the eternalist’s understanding of what it means to enjoy 34 KRITERION – Journal of Philosophy, 2016, 30(2): 29–60 temporal existence. Negative presentism indeed accepts the eternalist’s take on temporal existence and merely restricts the number of times, as we saw. So perhaps we can escape from triviality and absurdity if we manage to provide a positive account of ‘the nature of time’, of what it means to exist in time, that differs from the eternalist’s. Tallant’s proposal is an attempt to do so. He develops his own for- mulation of what he takes to be the thought underlying Merricks’s re- marks11, leading to what he calls ‘Existence Presentism’ (where “pres- ence” is to “is present” what “existence” is to “exists”): EP Presence is existence [39, p.494] Here, Tallant says, the “is” is to be read present-tensed (so no Meyer- inspired potentially threatening disambiguation of the copula is possi- ble). EP is not trivial: past things are not present, hence, by the identity of presence with existence, they don’t exist. Eternalists have to disagree here. Moreover, EP is not obviously false either. Thus, it seems that EP does not fall prey to Meyer’s complaint. As I announced earlier, we have indeed shifted from existence claims proper to a claim about existence.12 I think Tallant’s solution is on the right track. It points us towards a positive, non-eternalist account of ‘the nature of time’, of what it means to enjoy temporal existence, in the following way. The eternalist holds that existence is an atemporal notion, which acquires a temporal dimen- sion by being linked to times (which can be done either B-theoretically or A-theoretically; see §§3–4 below). On Tallant’s proposal, existence becomes an inherently temporal notion, and therefore no longer requires being linked to times.13 Yet a worry remains. For how should we understand the kinds of claims that refuted the other proposals I surveyed—past existence claims such as “Caesar existed”? Presumably, we should render that claim as follows: “WAS(Caesar exists)”. By EP, that should be equivalent to “WAS(Caesar is present)”. Now, if “is present” here functions rigidly (like the actuality operator in certain modal logics) this is clearly false: it was never the case that Caesar is (now) present. So the temporal operator “WAS” affects the contribution that “is present” makes to a statement. And that seems to suggest that the property which the phrase “is present” in the statement “WAS(Caesar is present)” denotes is different from the property it denotes in the statement “Tallant is present”. Perhaps the difference is that the latter denotes the property of being-present-now, while the former denotes the property of having- been-present? And if so, given that there has to be some kind of intimate relation between these two different presence-properties, it is natural to Jesse M. Mulder: Defining Original Presentism 35 say that the same should hold for the existence-property with which one of them is identical—differentiating it into existing-now and having- existed. This line of thought reduces EP to a triviality after all: of course existing now simply is being present-now, while having-existed simply is (or was) having been present—every eternalist would agree. (And the radical alternative—denying that Caesar existed—again moves us back to the absurdity of negative presentism.) But perhaps the worry can be laid to rest if we can clarify how exactly the “WAS”-operator works in a way that prevents this multiplication of presence-properties. That is, we should now discuss A-theory, the thesis that tense is fundamental, and, in particular, its relation to the presentism–eternalism issue.14 On this point, Kit Fine has argued that a proper understanding of A- theory in fact motivates a rejection of presentism. He puts the thought as follows (where his “ontic presentism” is what I’ve been calling, following tradition, “presentism”; while his “factive presentism” is what I call A- theory):

Ontic presentism is an ontological position; it is a view about what there is. Factive presentism, on the other hand, is a metaphysical . . . position; it is a view about how things are, quite apart from what there is. . . . Moreover, ontic presen- tism is a negative view; it excludes certain things from what there is. Factive presentism, on the other hand, is a positive view; it includes certain ways of being in how things are. . . . It is readily possible for a factive presentist not to be an ontic presentist. Indeed, he may endorse a full ontology of things past, present, and future: all such things may figure in his preferred account of reality . . . . He merely insists that some of the facts (if not all) should concern how things presently are. I am inclined to think that this version of factive presen- tism is much more plausible than the usual version, in which only present things are taken to exist; and it is a shame that a one-sided conception of the presentist issue has prevented philosophers from taking it more seriously. [18, p.299]

If Fine is right in thus contrasting presentism and A-theory (or, in his words, “ontic” and “factive” presentism), then tensing their statements is not going to help the defender of presentism. But Fine is wrong. As I will argue below (in §3), Fine’s liberal stand- point with respect to eternalism results from his implicitly accepting the 36 KRITERION – Journal of Philosophy, 2016, 30(2): 29–60 eternalist’s understanding of temporality. That implicit acceptance in- fects his understanding of tense—which he inherits from Arthur Prior’s tense logic. Whether or not temporal facts are tensed in this infected sense is of no help to the presentist: the ensuing A-theory is a mere variant of the underlying, eternalism-friendly understanding of time. It is not surprising that attempts to define presentism on such a basis fail. Before I turn to a critical examination of the understanding of tense underlying the debate on the definition of presentism, I first have to introduce the alternative understanding that underlies my own proposal. Juxtaposing the prevailing conception of tense with this alternative will help make clear where exactly things go wrong.

2 Forms of Predication

The above dialectical exercise motivates the search for a more funda- mental point of divergence between eternalists and presentists—which is, in fact, what Tallant, following Merricks, has also been looking for. Put somewhat cryptically, my suggestion is that we need to switch the logical background against which we attempt to define presentism. Let us first have a brief look at the prevailing logical background. The basis is Fregean: predicate logic. Underlying this logic, we find a certain form of predication: the one that Frege took to be analogous (or even identical) to mathematical function application [20, 21]. That is, the Fregean form of predication unites any given ‘concept’ (Begriff ) with a fitting number of ‘objects’ (Gegenst¨ande) to yield a unique proposition (Gedanke) that is either true or false. Thus, to this form of predication there corresponds a system of categories or formal concepts, in this case the categories of Begriff and Gegenstand. They are ‘formal’ in the sense of being defined by the described form of predication. Together, these formal categories constitute what I call the Fregean nexus. My use of ‘form’ here requires a bit of clarification.I focus on the form which a proposition has in virtue of the form of predication it embodies. That is an unusual sense of ‘form’. Usually, with ‘form’ one means to denote the diverse forms Fregean propositions can take, depending on the occurrences of logical constants and on the adicity of the predicates involved. I, however, want to focus on differences in form based on differences in form of predication. E.g., F a, Rab, and F a → ¬Gb all have different forms on the usual notion of ‘form’, but they have the same form in my sense: they all involve Fregean predication; F , G, and R fall under the formal category Begriff ; and a and b fall under the formal Jesse M. Mulder: Defining Original Presentism 37 category Gegenstand. This way of looking at the form of propositions is unusual because alternatives to the Fregean form of predication are only very rarely considered. The Fregean nexus is atemporal: time plays no role in its categories. Typical examples of the Fregean form of predication are atemporal—e.g., “3 [is] a prime number” (where [square brackets] indicate the Fregean, atemporal form of predication). The Fregean nexus lends itself to the kinds of formal systems that analytic philosophers are fond of. Predicate logic can of course be extended in various ways, for instance, by adding modal operators or tense operators. Such extensions do not change the underlying form of predication—as I will argue in the next section below. Since time plays no role in the form of Fregean propositions, it can only play a role by being introduced as bits of content. Temporal propo- sitions are then distinguished from atemporal ones not by form, but by content. The most straightforward way of doing so is by adding argu- ment places for times: e.g., the colloquial “The cat is on the table” gets analyzed as “The cat [is] on the table at t”.15 Thus, temporal propo- sitions are ordered in a series by way of these temporal indices, and the result is (a version of) B-theory.16 As we will see in the next sec- tion, tense logic is another, less straightforward way of supplementing atemporal Fregean propositions with features that yield the right kind of ordering. In both cases, the formal basis is the Fregean nexus, and the temporality of temporal propositions is accounted for by the rele- vant ordering. That is the hallmark of eternalism: if something exists, has existed, or will exist, there will be a suitable atemporal proposition relating it to the relevant point on that ordering—stating, in effect, that it [exists] at t. In other words, the Fregean nexus is inherently eternalist. There is, however, a quite different form of predication that is ade- quately described as being temporal. It gives rise to a different (larger) set of categories. It does not obviously lend itself to the kinds of for- mal systems that analytic philosophers are used to, which are invariably based on the Fregean form of predication. Propositions that exemplify this temporal form of predication are thus temporal not by content, but by form (in my sense). In fact, we are all very familiar with this form of predication. Con- sider the following sentences: T1 The cat is on the table T2 The cat was on the table T3 The cat is jumping to the ground 38 KRITERION – Journal of Philosophy, 2016, 30(2): 29–60

T4 The cat was jumping to the ground

T5 The cat has jumped to the ground

T6 The cat can jump (or: The cat jumps)

Three observations are in order. First, a familiar one: T1 and T2 unite the very same concept (being on) with the very same objects (the cat, the table), but they are different—they are differentiated in tense. I illustrate what this differentiation exactly amounts to below, from which it will become clear that it is impossible to model ‘is on’ and ‘was on’ as simply two different concepts in the Fregean sense. Secondly, a perhaps less familiar observation: T3, T4 and T5 also unite the same objects with the same concept in different ways, but here the differentiation is not merely in tense but also in aspect, with T3 and T4 being in progressive aspect while T5 is in perfective aspect. And, as has been repeatedly observed, T5 implies T4, but not vice versa, for the following may occur: while the cat was jumping to the ground, I caught it in mid-air so that it is not the case that the cat has jumped to the ground.17 Thirdly, and finally, there is another way in which activities may be joined to objects, in English expressible by use of a habitual sentence, as in T6: it unites them in a time-general way that is, in fundamental cases, not differentiated in tense or aspect. It is linked to the aspectual forms by entailment: from any sentence of the form T3, T4 or T5 the corresponding version of T6 follows.18 Thus we have a richly interrelated array of sentence-forms; because of those interrelations I regard them together as guises of one and the same form of predication (just as I consider predications of any arity to be exemplifications of one and the same Fregean, atemporal form of predication). It is apt to call this form of predication temporal predica- tion. In this paper, I focus on how recognition of this form of predication may contribute to a proper definition of presentism. For that purpose, one observation is of particular importance, namely, that differentiation in tense is not as straightforward as it seems. It is not that, using different tenses, one can construct different propo- sitions from the same materials. For, in the right circumstances, it may be that one says the same thing by uttering, e.g., first T1, then T2. One way to illustrate this is by considering disagreement: if A yesterday said “The cat is on the table”, then B can challenge his statement today by saying “the cat was not on the table”.19 And likewise, one can say different things by uttering T1 at different times. That is, the linguistic Jesse M. Mulder: Defining Original Presentism 39 forms of the sentences T1–T2 do not correspond to the logical forms of the temporal propositions they express.20 At this point, we can simply register this as a peculiarity of tem- poral predication: different sentences are required to express the same temporal proposition at different times.21 We should resist the tempta- tion to settle on a formulation (or formalization) designed to capture the form of the relevant proposition in abstraction from this peculiarity—it is simply the condition of stating (or thinking) temporal propositions in time that enforces the use of differently tensed sentences. I dwell on this point because it is not in line with the very paradigm understanding of tense that underlies most contemporary versions of A-theory, hence also of presentism: Prior’s tense logic. In that logic, the basic temporal bearers of truth are present-tensed atomic propositions that can differ in truth value over time. As I argue below, this assumption only makes sense if these basic temporal bearers of truth bear the form of Fregean propositions. And that is, I submit, the root of the difficulty of finding an appropriate definition of presentism. Anyway, as in the case of Frege’s atemporal predication, we may extract certain categories (formal concepts) from this temporal form of predication. Firstly, and most straightforwardly, we have the cate- gory of substance (corresponding to Frege’s Gegenstand).22 Secondly, we have, corresponding to Frege’s Begriff, two categories of predicables: feature/relation (such as ‘being round’ and ‘being on’) and activity (such as ‘jumping’). The difference between these two is indeed formal: ac- tivities occur in aspectually differentiated propositions, while features cannot. It is perhaps useful to take this more slowly in order to clarify the way this lifting of categories from a form of predication works. Frege thinks that the form of a thought—any thought—is based on his un- differentiated form of predication: predication as function application. Thus, the basic elements of thought are defined by this form of predica- tion. It differentiates between objects and concepts, and therefore these two categories can be lifted from his form of predication. The temporal form of predication I have introduced is, unlike Frege’s, differentiated. Suppose that it is the form of temporal thought as such—all temporal thought shares this form. Then, just as in the Fregean case, the basic elements of temporal thought can be lifted from this form of predication. As it is differentiated in tense and aspect, it gives rise not just to two but to three categories: substance, feature/relation, activity. These are, then, formal notions in the same sense as Frege’s categories of Gegen- 40 KRITERION – Journal of Philosophy, 2016, 30(2): 29–60 stand and Begriff are formal notions. In Frege’s case, this gives rise to observations such as that one cannot predicate the object 5 of the object 6. The form of predication forbids it. Likewise, in the case of temporal predication, one cannot predicate ‘is round’ of ‘the ball’ in an aspectu- ally differentiated way, nor can one predicate ‘jump’ of ‘the cat’ in the manner of a feature. The form of predication forbids it. Now, given its differentation, the temporal form of predication allows for a perspective that is unavailable in the case of Frege’s undifferenti- ated form of predication. The temporal form of predication includes three fundamentally different ways of joining appropriate elements to- gether: in a tensed way (T1–T2), in an aspected way (T3–T5), and in a time-general way (T6). Temporal thoughts are thus differentiated into three kinds: the tensed ones, the aspected ones, and the time-general ones. (We noted that these are not independent.) One can label the first passage, the second process (or change, or causality), and the third potentiality (or power). I should repeat: the content of these notions lies solely in the distinctions that the temporal form of predication allows for.23 This perspective on the form of temporal thought is unusual—I have frequently found it to meet with incomprehension. In the context of this paper, I can do no more than sketch its outline; for a mcuh more thorough articulation and defense of these categories themselves as well as of the understanding of logic and metaphysics that underlies it, I have to refer, again, to R¨odl’sseminal work Categories of the Temporal [34]. Interesting further questions concerning these categories and their interrelations can be asked: for instance, the dependence of aspect on tense is clear from examples like T3–T5, but what about the other direc- tion? Is tense conceivable without aspect? In effect, the question here is whether there can be passage of time without change. (The answer is “no”, but I won’t argue for that claim in detail here—however, see [34, chpt.5, esp.§4].) This indicates the ambition that lies behind the recog- nition of temporal predication as providing a logical framework different from the prevailing Fregean one: the framework it provides allows one to formulate metaphysical questions and views concerning a considerable range of topics related to time and causality—such as change, identity, persistence, and essence, to name the more obvious ones.24 These ‘categories of the temporal’ together constitute what I call the original temporal nexus: an interdependent cluster of formal concepts. If it is apt to call the system of forms to which Frege’s atemporal form of predication gives rise a ‘logic’ (or a family of logics), then it is equally Jesse M. Mulder: Defining Original Presentism 41 apt, though perhaps unusual, to call the system of forms to which the temporal form of predication gives rise a ‘logic’. My proposal is, thus, to take this ‘logic’, and not the Fregean one, as the proper logical back- ground for the project of defining presentism. Therefore, I have to ask the reader to not immediately think of the above considerations and the ensuing original temporal nexus as standing in need of analysis in ‘more perspicuous’ terms (such as tense logic). For what I am after is precisely to define presentism in terms of the irreducibility of this temporal form of predication. On a very abstract level, the irreducibility claim can be defended by noting, with R¨odl,that ‘nothing the apprehension of which does not involve the deployment of a given form of thought can justify its application’ [35, p.53]. That is, if certain propositions can be appre- hended without using the system of forms the original temporal nexus provides, then there can be no justification for its subsequent applica- tion to those propositions. E.g., we apprehend mathematical truths, such as “2 + 2 = 4”, by using the Fregean form of predication. And that prevents the original temporal nexus from being applicable: rephrasing “2 + 2 = 4” in temporal terms gives only the semblance of a proposition, but in fact is without sense. So any account of time in terms of the Fregean form of predication amounts to a proposed elimination of the original temporal nexus. Presentists should resist such elimination, on the ground that it amounts to an elimination of time itself. This ineliminability claim is the core thesis of what I call the original view: it takes temporal propositions to be differentiated from atemporal propositions by their form (in my sense of ‘form’), which is the temporal form of predication. In §4 below, I will discuss how the original view relates to presentism. A considerable obstacle for appreciating my proposal stems, interest- ingly, from Arthur Prior’s tense logic—despite his unrelenting engage- ment for presentism. I have already hinted towards the flaw that his tense logic-based conception of tense incorporates. That flaw takes cen- ter stage in the next section, after which I will return to my topic, the definition of presentism, in the final section, §4.

3 Tense and Tense Logic

As we have seen in the first section, definitions of presentism essentially make use of tensed statements. We saw that definitions of those shapes are deemed unsatisfactory precisely because the tensed statements they 42 KRITERION – Journal of Philosophy, 2016, 30(2): 29–60 involve are equi-acceptable to presentists and eternalists: apparently, the underlying conception of tense is neutral with regard to the presen- tism/eternalism controversy. At the end of that same section, I quoted Fine’s remarks in favor of ‘factive presentism’ (that is, generic A-theory) and against ‘ontic pre- sentism’ (that is, presentism): according to Fine, the A-theorist insists on temporal facts having a fundamentally tensed form, so to speak, but does not necessarily wish to deny the existence of past and future things. Fine’s conception of tense is thus equally neutral with regard to the pre- sentism/eternalism controversy. It is useful to see what exactly his con- ception of tense amounts to, for it is not the one that finds its home in the original temporal nexus. Rather, it ultimately rests on the Fregean, atemporal nexus, and is thus inherently eternalist. Fine distinguishes three versions of A-theory,25 all of which state that temporal facts are (or at least include such that are), fundamentally, tensed facts of the forms captured in Prior’s tense logic: p (present- tensed), Pp (past-tensed), Fp (future-tensed), etc. Consider, now, a standard, B-theoretic eternalist picture: it comprises the full collection of tenseless B-facts, ordered on the time line by the relevant (temporal) aspects of their content. What happens if we replace all these B-facts with tensed facts in this Priorian sense? The first thing to note is that Priorian tensed facts, unlike B-facts, do not tell us where they are located. Their ordering is lost. Hence the A- theorist needs a way of anchoring such facts to the right moments. The most familiar way is what Fine calls standard A-theory: it privileges the present time and replaces all the B-facts with A-facts oriented towards that time. But that is not the only option: as Fine shows, one can also be a non-standard A-theorist by rejecting such privileging of one point in time. That means that not only the tensed facts oriented towards the present time are included in reality, but also all the tensed facts oriented towards all the other times. Thereby, incompatible facts are included in reality: if yesterday p was true while today ¬p is true, then both p and ¬p are included in reality. Again, their ordering is gone. There are, now, two ways of dealing with this situation. The first is to relativize reality: each point in time has its own reality. Thus, the unity of reality is given up in order to sort the tensed facts to their proper ‘locations’. The second option is to endorse the incoherence of reality. The incoherence can then be locally resolved by saying that the incoherent “¨uber-reality” decomposes into coherent fragments. Fine calls the first option external relativism and the second option fragmentalism.26 Jesse M. Mulder: Defining Original Presentism 43

The details of these non-standard views do not matter much for present purposes. What does matter are the following observations. First, the standard A-theorist’s reality is in its entirety included in the realities of the non-standard realists—either as one of the many rela- tive realities, or (arguably) as one of the many fragments of the one incoherent ¨uber-reality. Secondly, and relatedly, the non-standard views incorporate many different versions of what are, from the standpoint of the original temporal nexus, the very same fact: for instance, yesterday’s p and today’s Pp. Thirdly, and most importantly, this raises the ques- tion as to why we should expect the many realities or fragments to mesh in the expected way: why can it not happen, for instance, that today’s reality contains Pp even though all earlier realities contain ¬p? This worrying question—and, indeed, the entire possibility of non- standard A-theories—rests on the time-relativity of truth that is inherent in the Priorian conception of tense. Prior’s tense logic captures only the interrelations between tensed statements from one and the same tem- poral perspective, but it doesn’t capture their cross-temporal sameness. That is, Prior is expressing something that goes beyond his own logic when he writes: In tense logic the totalities of tensed propositions which are true at different instants fit together into a system, so that although the total course of history will be differently de- scribed at different times, the description at one time will determine what the descriptions at other times will be. [33, p.38] Take, for instance, a simple present-tensed proposition p that is presently true. Using tense logic, one can infer that, therefore, it will be the case that it was true: FPp (ϕ → FPϕ is included as an axiom in virtually all tense logics). These two formulae are both presently true. One day passes: the proposition Pp is now presently true, from which we can infer, e.g, that PFPp is (presently) true (though not on the basis of the same axiom). But these two collections of truths are logically entirely independent: there is no way to connect yesterday’s truths (p, and FPp) with today’s (Pp, and PFPp) using the resources of tense logic.27 Considering an intellect capable only of grasping thoughts of these tense-logical forms, R¨odlputs this point as follows: Such an intellect is a totality of tense-logical contents, where- fore the system of these totalities is not accessible to him. One instance follows the other, and with it one totality takes 44 KRITERION – Journal of Philosophy, 2016, 30(2): 29–60

the place of the previous one. . . . The meaning of a tense- logical sentence resides in the conditions under which “is- present true” applies to it, and these are different at different times. Hence, as time passes, the meaning of all tense-logical sentences shifts. . . . Since the meaning of all of his sentences shifts, he has no means to say that it shifts. [34, p.106]

Analogously, we may say that a tense-logical reality is a totality of tense- logical facts (Fine’s varieties of A-theory are varieties of this thesis). What this means is best seen when we consider Fine’s external rela- tivist version of A-theory. On that view, there are different realities that contain instances of the same fact; e.g., yesterday’s reality contains p, today’s reality contains Pp. However, that yesterday’s p is identical with today’s Pp (or, if you prefer, that they express the same fact) is something that cannot be included in those realities as additional tense- logical facts. For one thing, the cross-temporal sameness of these addi- tional facts will then once more stand in need of being included by way of further facts of cross-temporal fact-sameness, leading to a regress.28 And for another thing, tense logic simply has no resources for saying that p and Pp are (or express) the same fact: to do so, one would need a fact connecting facts from two different realities (in the case of external relativism)—and to which reality would such a fact belong? Let us take this a little bit slower. The defender of tense logic might say, speaking about tense-logical formulae from a meta-perspective: “p’s past truth is mirrored in Pp’s present truth, and that is ensured by FPp’s past truth”.29 Now, assume that this statement itself is a statement bearing tense-logical form. Focus on the first bit: what would it be to talk, tense-logically, about p’s past truth? The notion of past truth will have to be explained in tense-logical terms: ‘ “p was true in the past” is true just if Pp is true’. That is, the notion of ‘past-truth’ just is the past-operator P. So the first bit of our statement says, in effect, that Pp is mirrored in Pp. Saying that p was true does not get one beyond saying that Pp is true. Thus, such an attempt to formulate the cross-temporal interdependencies of time-relative truth, if read as itself a tense-logical statement, simply says something that is-present-true of the sentences (or formulae) p, Pp, and FPp. It expresses how various present-truths and present-falsehoods, concerning which formulae were, are, and will be true, hang together. That does not tell us how their present-truths and present-falsehoods hang together with truths and falsehoods at other moments. What we attempt to say about this turns out to be, again, present-true or present-false—at least, as long as we are required to Jesse M. Mulder: Defining Original Presentism 45 move within the realm of tense-logical forms. The point is that, by making truth time-relative, as tense logic does, one is simply deprived from the means of saying anything whatsoever about what is true at other moments. We always and invariably end up saying what is-present- true about what is-past-true (or future-true). We require, for instance, that p’s past truth be reflected in Pp’s present truth. That requirement, if it is to state what we want it to state, cannot itself be a tense-logical statement.30 Fine’s non-standard versions of A-theory bring out this cross- temporal independence—indeed, they are only possible because of this independence. On standard A-theory, one could argue that all there is is the present-truth of past- and future-tensed propositions; all there is is tensed facts oriented towards the present. Fine shows that this is optional: one can also endorse versions of A-theory that deny this priv- iledging of the present moment, thus making room for all of the tensed facts oriented towards other moments as well. The totality of tensed facts oriented towards the present is then completely disjoint from the totality of tensed facts oriented towards earlier and later moments (al- though in the case of fragmentalism they may overlap). Indeed, to repeat R¨odl’sway of putting things, “one instance follows the other, and with it one totality takes the place of the previous one”. There is no way of saying anything about how those totalities relate using tense-logical forms. One might try saying that we should thus simply reject Fine’s non- standard forms of A-theory. But the point is, precisely, that the underly- ing understanding of tense allows for them. An adequate understanding of tense should rule out such forms of A-theory—it should incorporate the cross-temporal integration that Prior’s tense logic fails to capture. The understanding of tense embodied in tense logic is thus not the one we found in the original temporal nexus. If my sketch of the Fregean, atemporal and the original, temporal forms of predication is right, one expects that anything falling short of the temporal form of predication (such as Prior’s tense logic) must rest on atemporal predication. And so it does. To see why, it is helpful to reconsider negative presentism—the view that takes the eternalist’s time line and erases all but the present mo- ment. A would-be negative presentist will claim that the truths concern- ing the one moment he acknowledges (the present) are present-tensed truths. But why, we may ask, are these present-tensed truths and not simply atemporal truths (exemplifying the Fregean form of predication)? 46 KRITERION – Journal of Philosophy, 2016, 30(2): 29–60

The negative presentist can do nothing to distinguish his view from an eternalist, B-theoretic view of a temporally thin reality.31 The underly- ing problem here is, again, nicely stated by R¨odl: [If] a present tense formula is elementary, then the contrast to the corresponding past tense formula is not part of its [con- tent], and without this contrast, “present” has no temporal meaning. [34, p.107] The original temporal nexus does include that contrast in its conception of temporal truth: differently tensed sentences do not state differently tensed propositions whose truth (or falsehood) is time-relative—rather, temporal propositions whose truth (or falsehood) is time-absolute have to be expressed by using suitable, differently tensed sentences as time passes.32 Consider, by way of analogy, a reductive view of modality like Lewis’s [23]. What is crucial, for such a reductive project, is to isolate modality completely. In its simplest, propositional form, that is achieved by estab- lishing a stock of a-modal elementary propositions, p, q, etc., to which modal operators can then be prefixed in order to make modal statements. The elementary propositions are true or false, and can be understood, in complete independence from their ‘modalized’ versions. The reduction then proceeds by analyzing the modalized versions in terms of their el- ementary counterparts at other worlds. The result is a relativization of truth to worlds. Something similar happens in the case of tense logic: there is a stock of atemporal elementary propositions, p, q, etc., to which tense oper- ators can be prefixed in order to make ‘tensed’ statements, that can subsequently be reduced to their atemporal counterparts at other times. The result is a relativization of truth to times. Prior, of course, both resisted the reduction and insisted that the elementary propositions are present-tensed—but, again, mere insistence is not enough. What is re- quired is the kind of temporal integration that, as we saw, is precluded by relativizing truth to times. In other words, what is required is the signature of tense that the original temporal nexus recognizes. The fundamental claim of eternalism is that time is the time-line: temporal propositions are internally atemporal, that is, they have an atemporal form; their temporality consists in their being suitably or- dered, in some way or other. As we have seen, there are various ways of spelling this out. Standard B-theory is one such way: it incorporates temporality, in the end, by way of an extra piece of content—a specifica- tion of the temporal location. Fine’s versions of A-theory are other such Jesse M. Mulder: Defining Original Presentism 47 ways—despite appearances. Even negative presentism is one such way, though a limiting case. Unfortunately, for Prior, his attempt to arrive at a genuinely non-reductive logic of tense thus turns out to provide excellent materials for a sophisticated reductive understanding of tense. These considerations shed a new light on my survey of attempts to arrive at a definition of presentism in the first section above. As long as tense is conceived so as to be consistent with this fundamental eternalist claim, it does not matter whether the quantifiers are tensed or not: we will remain stuck with statements that are either trivial, because they are restricted to the present moment, or absurd, because they restrict the whole time line to the present moment. Again, what we need is not a different view on the number of times, but rather a different view on what it is to exist in time, that is, on the nature of time (as Merricks and, following him, Tallant, suggest). The original temporal nexus promises to deliver such a different view on the nature of time—as I hope to show now.

4 The Original View and Presentism

Our situation is as follows. Attempted definitions of presentism were unsatisfactory because they failed to deliver an unambiguous thesis on which presentists and eternalists could disagree. This motivated a look at the logical background against which the search for such a defini- tion proceeds. That logical background is biased towards eternalism: its core is the Fregean nexus, which rests on an atemporal form of predica- tion. My discussion of the tense-logical understanding of tense, which is supposed to provide a presentism-friendly alternative to B-theory, un- derwrites this conclusion: it too rests on the Fregean nexus. I contrasted the Fregean nexus with the original temporal nexus, which rests on an alternative, temporal form of predication. The original view takes this original temporal nexus as its starting point. We now need to understand how presentism relates to the original view. As said, eternalism does not take the temporality of temporal propo- sitions to consist in their having a distinctive form; temporal proposi- tions are formulable using the familiar, Fregean atemporal form of pred- ication. Thus, the temporality of temporal propositions consists either in some aspect of their content, such as an explicit or implicit reference to a temporal location, absolute or relative, or it consists in some other feature—such as their truth (or falsehood) being time-relative. In all cases, time enters the picture by way of a time line (or a similar order- 48 KRITERION – Journal of Philosophy, 2016, 30(2): 29–60 ing) on which temporal propositions are to be anchored. And the same holds for the objects such propositions are about: they are objects ex- isting in time by being located on certain location(s) on the time line. Their respective locations are revealed once we have the full analysis of temporal propositions concerning them before us. That is, in the case of classical B-theory, the locations of the objects are given as the tem- poral references included in such propositions; in the case of A-theoretic versions of eternalism, the locations of the objects figuring in temporal propositions transpire from their position on the ordering grounded in the assumed time-relativity of truth. Therefore, understanding temporal propositions as involving the Fregean, atemporal form of predication im- plies that for any temporally existing thing x, one can always formulate a true, atemporal proposition of the form “x [exists] at t” (recall that I use [square brackets] to indicate the atemporal form of predication).33 And that, one might say, is the core thesis of eternalism. By contrast, the original view does take the temporality of tempo- ral propositions to consist in their having a distinctive form—namely, the temporal form of predication (with its many guises). One may, of course, position propositions of that form on a time line, as is done in chronological overviews of many types, yet the crucial difference is that one does not thereby explain their temporality. This holds also for exis- tence statements: saying “Caesar existed”, I am reporting the very same temporal proposition that a contemporary of Caesar could have said by saying “Caesar exists”.34 I can even say “Caesar existed at t”. But due to formal mismatch, there is no proposition of the form “Caesar [exists] at t”, and thus temporally existing objects in the sense of the original view (that is, substances) simply cannot function as inhabitants of the eternalist’s time line. The formal mismatch arises as follows. The core thesis of eternalism I mentioned—that for any temporally existing thing x, there is always a true, atemporal proposition of the form “x [exists] at t”—is only for- mulable using the Fregean, atemporal form of predication. If we depart from the original view, no such statement is formulable. For suppose we start with “Caesar existed”: “Caesar”, here, names a substance—a category defined by the temporal form of predication. If we replace it with “Caesar [exists] at t”, we are doing more than just replacing the form of predication involved. We also change the logical character of the name “Caesar”—in this context, it is a name for a Fregean Gegenstand, a category defined by the atemporal form of predication. That Gegen- stand cannot be identical with a substance—for the same reason why Jesse M. Mulder: Defining Original Presentism 49 an individual thing cannot be identical with a property: they belong to different categories. Not only the form of predication, but also the for- mal categories of the things it applies to (substances, features, relations, activities) rests on the original view.35 From these considerations, it transpires that eternalism is only for- mulable within the Fregean nexus. My claim is, now, that presentism is only satisfactorily formulable within the original view. In particular, eternalism is formulable within the Fregean nexus because that nexus in- cludes an atemporal notion of existence. Negatively speaking, then, on the original view presentism can be defined in terms of the rejection, on formal grounds, of a tenseless notion of existence (at least as applied to temporally existing things). Temporal propositions just do not have the right form to allow for anything resembling a statement of eternalism. From the perspective of the original view, then, the first thing to ask when confronted with a putative definition of presentism is: what is the form of the proposed defining statement? Take, for example, Meyer’s target definition of presentism, with which I started my investigations: P Nothing exists that is not present. [30, p.213] Meyer challenged this claim on the grounds that it is either trivial (on a present-tensed reading of ‘exists’) or untenable (on a temporally general reading of ‘exists’). So there seemed to be no room for a distinctively presentist reading of P. But which form of predication is used? If we are to understand Meyer’s tensed quantifiers along tense-logical lines, we are already in eternalist territory, and the game is lost before we even got started. Now, reading P as involving temporal predication, it still holds good only on its present-tensed reading—and it is, indeed, still trivial. That, however, is no longer a problem, for the defender of presentism can point to the difference in form of predication to mark off his position from the eternalist’s, who is committed to there being temporal propositions of the form “x [exists] at t”. In other words, the point of endorsing P, for a defender of the original view, lies in endorsing the form of predica- tion it exemplifies. And that is not trivial at all. An eternalist reads P differently: he understands the present tense, ultimately, in terms of a location on his time line. Taken as intended by the defender of the original view, then, P does suffice to generate a difference between pre- sentism and eternalism, albeit in a rather roundabout way, namely, by exemplifying the original temporal nexus.36 This sort of definition of presentism, in terms of an existence state- ment involving the temporal form of predication, is, thus, trivial in a 50 KRITERION – Journal of Philosophy, 2016, 30(2): 29–60 peculiar way. What the defining statement says—its content—is trivial; its real contribution lies in the form it displays. Moreover, that form pre- vents an eternalist from recognizing its trivial contents—the eternalist rejects the temporal form of predication. True, she can make a seemingly very similar statement, using the same form of words, and thereby ex- press something that is trivial by her own lights—involving the Fregean, atemporal form of predication. But that does not affect the proposal, of course. The triviality objection against definitions of presentism, with which I started this paper, thus does not get off the ground. In any case, such a proposal isn’t very helpful: the fundamental point of disagreement between eternalism and presentism is only implicit in it, not explicit. Things are different with Tallant’s proposal, which is not in terms of an existence statement but rather in terms of a statement about existence:

EP Presence is existence [39, p.494]

This definition comes closer to making explicit what is only implicit in my original view based rendering of P. It says what existence is, for temporal objects.37 But, as I suggested at the end of the first section, this definition seems to leave room for a worry, since it is unclear how we should understand past existence claims such as “Caesar existed”. Such a claim is plausibly rendered “WAS(Caesar exists)”, which is, by EP, equivalent to “WAS(Caesar is present)”. Now, my worry was that it is unclear whether “is present” here denotes the same property that it denotes in the context of, say, “Tallant is present”. We can now see that that worry only makes sense if we adopt an eternalist point of view on which temporality is to be accounted for in terms of being located somewhere on the time line. From that point of view, there are two options. Either “is present” in the final analysis always denotes the property of [existing] at the present moment, in which case it will not be true to ascribe that property to Caesar (for he doesn’t exist now); or, on the other hand, the property “is present” denotes shifts along with the tense operator “WAS”, in which case it looks like EP turns into a triviality. But we can resist this eternalist rendering of EP: instead, we can in- terpret it from the logical perspective of the original view. On that view, EP implies that “Caesar existed” is equivalent to “Caesar was present”. Now, I observed, in §2, that sentences involving the past tense express the very same temporal proposition that would earlier have required a present-tense sentence. Thus, most importantly, I do not suppose the Jesse M. Mulder: Defining Original Presentism 51 involvement of a temporal operator, “WAS”, that takes us to an ear- lier point on the time line, where we may then find a true (atemporal) proposition “Caesar [is] present”. That is what we get if we take the tense-logical approach, on which truth is time-relative. On the original view, “Caesar was present” simply expresses the very same temporal proposition Caesar himself could have formulated by saying “Caesar is present”. That makes clear both that there cannot be different proper- ties of “being present” associated with different times, and that the one unique property of “being present” cannot be rigidly tied to the present moment.38 On the original view, we simply have truths exemplifying the temporal form of predication. These are basic; their temporality lies in their form, not in their being tied to an assumed time line. As in the case of proposed definition P, we find, with regard to EP, that the same form of words can be used by a presentist to present his view, and by an eternalist to say something fundamentally different. That is because the difference lies in the form of predication used. A statement always involves some form of predication, and therefore there is no neutral, common ground on which a defining statement can be formulated. Tallant’s proposal is a move in the right direction; on my reading, it highlights a feature of the original view. But we can be more explicit. So, here is my proposal: OP Temporal propositions display the temporal form of predication. OP says that temporal propositions instantiate the temporal form of predication on which the original view rests, and thus I call a presentist that subscribes to OP an original presentist. Original presentism and eternalism disagree on OP: the eternalist has to reject it. That is because the eternalist understands temporal truth in terms of the atemporal form of predication combined, in some way or other, with a time line. And that amounts to an elimination of the temporal form of predication, contradicting OP.39 It is likely felt that the question still remains: why should we take OP to yield a version of presentism? Why is it not, instead, a novel definition of A-theory, perfectly compatible with a ‘full ontology of things past, present and future’, as I quoted Fine saying [18, p.299]? I already gave the short answer to this question above. As I argued, a ‘full ontology of things past, present, and future’, in the relevant eter- nalist sense, requires that we be able to say of any object included in that ontology that it (atemporally) [exists] at some t. If temporal propo- sitions involve the temporal form of predication, we cannot say anything of that kind. Hence OP indeed yields a version of presentism. 52 KRITERION – Journal of Philosophy, 2016, 30(2): 29–60

A much longer answer to this question can be developed, based on a proper elaboration of the original view. I can only sketch the rele- vant considerations very briefly here. I remarked that the original view exhibits a close interconnection between time and causality—between tense and aspect, that is. From that interconnection it transpires that objects to which temporal predication applies (that is, substances) are enduring things capable of causal interaction. And endurance, in the end, only makes sense against a presentist background (although, like in the case of A-theory, eternalism-friendly versions of endurantism can be formulated as well, based on the Fregean nexus).40 As should be clear by now, the original view encompasses more than just presentism. Properly developed, it may yield a comprehensive meta- physics of time, substance, causality, and more. It remains to be seen to what extent the original temporal nexus can indeed serve as a viable basis for such a comprehensive metaphysics. For all I have argued here, it may still turn out that we do best to discard it. But I hope to have made a case for the claim that the future of presentism depends on it.

Notes

1 I will largely restrict myself to the presentist’s attitude towards the past here, since the future invites problems of its own, concerning its being or not being open, determinate, or determined, that are not essential to my argument. More- over, I ignore abstract objects, which, for most presentists, would exist despite arguably not being present in any interesting sense. 2 Hence, I differ from McTaggart’s original definition, in terms of properties like “being future”, “being present”, and “being past”, which are thought to be had by times (making up the so-called A-series) [27, esp. p.458]. My reasons for differing in this way will become apparent later on. 3 Interesting examples of eternalist A-theories can be found in Kit Fine [18]. I briefly look into those in §3 below. Arguably, there is room for a B-theoretic version of presentism that claims that there is, fundamentally, only one moment— the present—and thus only one B-relation: simultaneity. Such a version would presumably not find many defenders. As we will see below, it is identical with the view I call ‘negative presentism’. 4 The challenge Meyer develops appears to have found its first serious expression in a discussion between Crisp and Ludlow in Oxford Studies in Metaphysics, vol. 1 —see [11, 12, 25]. 5 The very same phrasing of the presentist thesis can be found in, e.g., [9, p.35]. 6 And, we may add, reading the “is” in P2 temporally general as well again leads to a triviality. In what follows, I will phrase the dilemma that the presentist faces as one of having to choose between a triviality and an absurdity (so that the view is either trivial or untenable). In the discussion, the dilemma is often Jesse M. Mulder: Defining Original Presentism 53

phrased as a choice between a reading that is trivially true and one that is trivially false. Although it is a minor point, I think that is a mistake: while P1, for instance, arguably expresses a tautology, and is thus trivially true, P2 is not a contradiction—it’s just an absurd claim to make. 00 7 Crisps definition reads: Prb For every x, x is a present thing [11, p.18]. 8 Crisp is thus gesturing towards a tensed model theory for his temporal quantifiers. 9 Tallant discusses more proposed definitions than the ones I here present; for instance those by Sider, who tries to establish inferential differences between the presentist and the eternalist quantifiers [37], and by Stoneham, who thinks a difference in the attitude towards truthmaker principles can be established [38]. And still others can be added. Though interesting in their own right, my selection provides me with enough materials to make my point. 10 As Tallant also notes, the same definition has been proposed by Zimmerman, who writes that “to be present just is to be real or to exist” [45, p.117]. 11 Tallant thinks that Merricks’s (and Zimmerman’s) formulation is flawed because we can still apply a Meyer-style objection. If existing at the present time just is existing, we can read the “just is” either as present-tensed or as temporally general: the first reading, says Tallant, is then trivial, the second absurd. But the first reading is not trivial: Tallant confuses the non-trivial (1) “existing at the present time just-is-now existing” with the trivial (2) “existing at the present time just-is existing now”. This observation doesn’t affect Tallant’s proposal, however, because (1) is plausibly a statement of that very proposal. 12 Tallant goes on to consider how one might understand the identity claim EP: it can be read as the identification of the properties of existence and presence—but, of course, there are those who don’t accept existence as a property. Thus, an alternative is to read it as identifying the ontological category of existence with that of presence. For reasons of scope, I ignore such considerations concerning the wider debate on existence in the present paper. 13 Notice that Tallant thereby in effect rejects the very idea of times as locations, central to the eternalist picture. That will turn out to be a crucial ingredient in my own proposal as well; see §4 below. 14 As I noticed at the beginning of this paper, I conceive of A-theory broadly, so as to be compatible with eternalism. 15 Notice that these two statements have a different ‘form’ on the usual under- standing of that term (namely, Rxy and Rxyz, respectively), but not on my understanding. I say that it is a difference in content because it is just a matter of putting together different ingredients with the help of the Fregean form of predication. Of course, adding an argument place to a given predicate invites the familiar question whether that doesn’t amount to changing the topic—but that is not my concern here. 16 The index may be built into the content of temporal propositions in different ways, depending on one’s preferred views on the matter—e.g., as an index to the object(s) in question specifying the relevant temporal part(s), yielding per- durantism, or simply as an argument place for the predicate, yielding a form of endurantism. 17 This is called the ‘imperfective paradox’ in linguistics [17]. In action theory, attention was drawn to the progressive by Anscombe [1], and, more recently, by R¨odl[35, chpt.2] and Thompson [40, chpt.7–8]. Notice, by the way, that no 54 KRITERION – Journal of Philosophy, 2016, 30(2): 29–60

interesting differentiation in tense applies to T5: the past perfect tense (e.g., “The cat had jumped to the ground”) expresses the same completeness of a process that the present perfect expresses. It does serve further, pragmatic functions— but that is not relevant for my purposes. In other languages (such as Russian, with its lexical duplication of each verb into a progressive and a perfective one) aspect and tense are in this respect somewhat more cleanly separated. 18 For simplicity, I do not discuss T6 in much detail, nor its further generaliza- tion to the generic “Cats jump”—that would get us into complex considerations concerning the nature of cats (and concerning natures generally—but see [31]). And, to repeat, for similar reasons I eschew discussing the future tense. For a much more elaborate investigation into tense, aspect and the time-general as in- terrelated characteristics of the temporal form of predication, see, respectively, chapters 4, 5 and 6 of R¨odl’s[34]. 19 Does this mean that that ‘very same temporal proposition’ is an atemporal B- fact? No: that only follows if one insists that there must be a presentation of that proposition that is independent of its expression using tensed sentences. See also note 32. 20 Similar, but slightly different, observations apply to the aspectual differentiation displayed by T3–T5. In particular, while one is saying different things by uttering T1 at subsequent times, the same doesn’t hold for T3: there, the very same statement remains true for as long as the cat jumps (in other words, processes, like substances, endure). Such observations are, however, not central to my aim in this paper. 21 My insistence on tense as a feature of the form of predication might be thought similar to the ‘multiple instantiation tie’ approach to presentism developed by McKinnon and Bigelow [26]. They write: “it is curious that this thought—that pastness and futurity are to be located in instantiation—has been neglected by presentists.” But the peculiarity of temporal predication I just noticed, con- cerning the way in which past- and present-tensed statements relate, sets my approach apart from theirs. And the same holds with regard to the tensed quan- tifier approach explored by Baron [8] as a way of dealing with truthmaker issues. Thanks to an anonymous referee for pointing out these relations to me. 22 There are good reasons for choosing the Aristotelian term “substance” here: Aristotelian substances are what remains constant through change, and that is precisely the role that the temporal form of predication has them play. For present purposes, however, I do not need to defend this claim—here, I simply need a term different from ‘object’, to flag the distinction from Frege’s Gegenstand category. 23 Like the categories of substance and potentiality, others from our list can be associated with certain notions central to Aristotle’s metaphysical thought: in particular, the category of feature/relation corresponds to stasis, while process corresponds to kinesis. 24 Given this broad scope, I can only sketch the rough outline of this logical frame- work in the present paper, geared towards my topic: the definition of presentism. 25 Fine calls this ‘tense-theoretic realism’ or just ‘realism’. For clarity, I here stick to the label ‘A-theory’ instead of ‘realism’. 26 Fine argues that fragmentalism is to be preferred, because it promises to make more sense from the point of view of relativity theory—it allows, for instance, for overlapping fragments. Jesse M. Mulder: Defining Original Presentism 55

27 Nor does it help to resort to tense-logical meta-propositions about the truth or falsity of tense-logical formulae: the present truth of “ ‘Pp’ will be true” remains unconnected to the present truth, one day later, of “ ‘Pp’ is true”. The problem lies in the time-relativity of truth. 28 As Wittgenstein notes in Zettel 693 [43], the problem of an infinite regress is not so much its infinity but rather its disabling any understanding of its members—in this case, any understanding of cross-temporal fact-sameness. See also [35, p.25]. 29 This sentence comes from an anonymous referee, whom I thank for pointing out the need to clarify this. 30 Thus, it doesn’t matter for the point I am raising to which ‘grade of tense-logical involvement’ one is willing to subscribe [32, chpt.XI]—all of them are, after all, grades of tense-logical involvement. One can see this from what Prior writes, towards the end of his explorations of these grades, about “the vacuity” that “ ‘It is now the case that—’ has in ordinary tense logic; it does not need to be expressed, but is understood in all that we say.” (p.134, my emphasis). If it is really understood in all that we say, we are indeed forever banned within ‘what is now the case’—within what is-present-true. Prior’s ‘translation project’ in the mentioned paper succeeds insofar as it enables one to translate everything one can say using the ‘earlier-later calculus’ using only tense-logical propositions, the truth or falsity of which is relative to the present moment. The success of that project, however, does not address our worry. 31 This is the one non-A-theoretic version of presentism I mentioned in note3 above. 32 This time-absolute understanding of temporal truth is criticized by Cord Friebe [22, §I.A.2.1], who follows Mellor [28, p.30] in concluding from a temporal truth being time-absolute that that truth has to be a B-theoretic truth. That, however, merely shows how entrenched the assimilation of temporal predication to Prior’s tense logic has become: if truth is not time-relative, then only B-theory remains. And that is a non sequitur. 33 In case one wants to hold onto A-theory in the way Fine does, there will be no such propositions, as it is denied that there are any propositions whose truth is time-independent. However, we saw that in that case, there still is, for any temporally existing thing x, the proposition ‘x [exists]’, which is true relative to some t. 34 Does this mean that that ‘very same temporal proposition’ is an atemporal B- fact? No: that only follows if one insists that there must be a presentation of that proposition that is independent of its expression using tensed sentences. See also note 32. 35 In fact, the formal mismatch goes even deeper. In the case of Fregean proposi- tions, one can safely abstract from the fact that judgments, thoughts, utterances etc. are made in time. While, as can be seen from my exposition of the original temporal nexus in §2, that is not so easy in the case of temporal propositions bearing the form captured in the ogirinal temporal nexus. That is the reason why R¨odl,to whose work I owe my approach to the presentism issue, gave his book the subtitle “An Inquiry into the Forms of the Finite Intellect” [34]. That is also the reason, I should add, why I refrain from proposing any serious formalization of the claims I use for explicating the original temporal nexus and the version of presentism it yields (see below). It is the downside of the habit of supplying formal renderings in analytical philosophy that these are always derived from 56 KRITERION – Journal of Philosophy, 2016, 30(2): 29–60

the Fregean nexus—as my critical discussion of tense logic in the previous sec- tion illustrates. Perhaps a radically different formalism can be developed for the original temporal nexus—but I would not know how. 36 Similarly, Crisp’s definition of presentism is acceptable to a defender of the origi- nal view, though equally trivial. Moreover, Crisp’s tensed reading of the domain of temporal quantification, which he uses in his attempt to rebut counterexam- ples that rely on past objects, can be understood to be in line with the original view. On such a reading, the domain of temporal quantification changes over time: it used to contain Julius Caesar, but doesn’t do so anymore. As long as we understand tense, as it figures in this view of quantification, in terms of the original temporal nexus (and not, say, in terms of Priorian tense logic), all of this is perfectly fine. 37 This is analogous to Aristotle’s famous remark explicating what existence is for living things: ‘to exist, for a living thing, is to live’—see [2, p.27; II.5, 415b12–14]. 38 I speak, here, of the “property of being present”, following Tallant, whose claim EP is after all to be understood as an identification of properties. I do not think this ultimately makes sense; I am more inclined to accept Tallant’s alternative rendering of his proposal in terms of the identification of the ontological category of existence with that of presence [39, §3.3]. However, I would then urge for an understanding of ontological categories based on my notion of forms of predica- tion, in which case there would be room for more than one notion of existence. However, I cannot develop the details of such a proposal here. 39 A pessimistic thought may come to mind at this point: the eternalist may simply disagree on the question whether or not there is something to be eliminated here at all. He may claim that there is no such thing as the ‘original temporal nexus’, that there is only tense, aspect, and the like in the sense in which they fit his theory (however that may be). If so, I don’t think there’s much more to say: like Quine’s denial of modal talk (of sufficiently robust grades), such a denial of the temporal nexus is just that: an outright denial of a fundamental element of our understanding of reality. 40 For a detailed investigation into the temporal form of predication, see [34]—as I said earlier, I owe my approach to the presentism issue largely to R¨odl’swork.

Jesse M. Mulder Utrecht University Janskerkhof 13, 3512BL Utrecht, The Netherlands Jesse M. Mulder: Defining Original Presentism 57

References

[1] G. E. M. Anscombe. Intention. Cambridge, Mass.: Harvard Uni- versity Press, 1957. [2] Aristotle. On the Soul. Princeton: Princeton University Press, 1984. [3] Jamin Asay and Sam Baron. “The Hard Road to Presentism”. In: Pacific Philosophical Quarterly 95.3 (2014), pp. 314–35. [4] Alex Baia. “Presentism and the Grounding of Truth”. In: Philo- sophical Studies 159.3 (2012), pp. 341–56. [5] Mark Balaguer. “Anti-Metaphysicalism, Necessity, and Temporal Ontology”. In: Philosophy and Phenomenological Research 89.1 (2014), pp. 145–67. [6] Sam Baron. “Presentism and Causation Revisited”. In: Philosoph- ical Papers 41.1 (2012), pp. 1–21. [7] Sam Baron. “Talking About the Past”. In: Erkenntnis 78.3 (2013), pp. 547–60. [8] Sam Baron. “Tensed Truthmaker Theory”. In: Erkenntnis 80.5 (2015), pp. 923–44. [9] John Bigelow. “Presentism and Properties”. In: Philosophical Per- spectives 10 (1996), pp. 35–52. [10] Ben Caplan and David Sanson. “Presentism and Truthmaking”. In: Philosophy Compass 6.3 (2011), pp. 196–208. [11] Thomas M. Crisp. “On Presentism and Triviality”. In: Oxford Studies in Metaphysics, Vol. 1. Ed. by Dean W. Zimmerman. Ox- ford: Clarendon Press, 2004. Chap. 2, pp. 15–20. [12] Thomas M. Crisp. “Reply to Ludlow”. In: Oxford Studies in Meta- physics, Vol. 1. Ed. by Dean W. Zimmerman. Oxford: Clarendon Press, 2004. Chap. 2, pp. 37–46. [13] Rafael De Clerq. “Presentism and the Problem of Cross-Time Rela- tions”. In: Philosophy and Phenomenological Research 72.2 (2006), pp. 386–402. [14] Dennis Dieks, ed. The Ontology of Spacetime. Amsterdam: Else- vier, 2006. 58 KRITERION – Journal of Philosophy, 2016, 30(2): 29–60

[15] Mauro Dorato. “Presentism/Eternalism and Enduran- tism/Perdurantism: Why the Unsubstantiality of the First Debate Implies That of the Second”. In: Philosophia Naturalis 49.1 (2012), pp. 25–41. [16] Mauro Dorato. “The irrelevance of the presentism/eternalism de- bate for the ontology of Minkowski spacetime”. In: The Ontology of Spacetime. Ed. by Dennis Dieks. Amsterdam: Elsevier, 2006, pp. 93–109. [17] D. Dowty. “Toward a Semantic Analysis of Verb Aspect and the English ‘Imperfective’ Progressive”. In: Linguistics and Philosophy 1.1 (1977), pp. 45–77. [18] Kit Fine. “Tense and Reality”. In: Modality and Tense: Philosoph- ical Papers. Oxford University Press, 2005, pp. 261–320. [19] Marcello Oreste Fiocco. “A Defense of Transient Presentism”. In: American Philosophical Quarterly 44.3 (2007), pp. 191–212. [20] Gottlob Frege. “Funktion und Begriff”. In: Funktion, Begriff, Be- deutung. F¨unflogische Studien. Ed. by G¨unther Patzig. G¨ottingen: Vandenhoeck & Ruprecht, 1891, pp. 18–39. [21] Gottlob Frege. “Uber¨ Begriff und Gegenstand”. In: Vierteljahress- chrift f¨urwissenschaftliche Philosophie 16 (1892), pp. 192–205. [22] Cord Friebe. Zeit – Wirklichkeit – Persistenz: Eine pr¨asentistische Deutung der Raumzeit. Paderborn: mentis, 2012. [23] David K. Lewis. On the Plurality of Worlds. Blackwell Publishing, 1986. [24] David K. Lewis. “Tensing the Copula”. In: Mind 111.441 (2002), pp. 1–13. [25] Peter Ludlow. “Presentism, Triviality, and the Varieties of Ten- sism”. In: Oxford Studies in Metaphysics, Vol. 1. Ed. by Dean W. Zimmerman. Oxford: Clarendon Press, 2004. Chap. 2, pp. 21–36. [26] Neil McKinnon and John Bigelow. “Presentism, and speaking of the dead”. In: Philosophical Studies 160.2 (2012), pp. 253–63. [27] John M. E. McTaggart. “The Unreality of Time”. In: Mind 17.68 (1908), pp. 457–74. [28] David H. Mellor. Real Time II. London: Routledge, 1998. [29] Trenton Merricks. Truth and Ontology. New York: Oxford Univer- sity Press, 2007. Jesse M. Mulder: Defining Original Presentism 59

[30] Ulrich Meyer. “The Presentist’s Dilemma”. In: Philosophical Stud- ies 122.3 (2005), pp. 213–25. [31] Jesse M. Mulder. “The Essentialist Inference”. In: Australasian Journal of Philosophy 91.4 (2013), pp. 755–69. [32] Arthur N. Prior. Papers on Time and Tense. Oxford: Oxford Uni- versity Press, 1968. [33] Arthur N. Prior and Kit Fine. Worlds, Times and Selves. Amherst: University of Massachusetts Press, 1977. [34] Sebastian R¨odl. Categories of the Temporal: an Inquiry Into the Forms of the Finite Intellect. Cambridge, Mass.: Harvard Univer- sity Press, 2012/2005. [35] Sebastian R¨odl. Self-Consciousness. Cambridge, Mass.: Harvard University Press, 2007. [36] Steven Savitt. “Presentism and Eternalism in Perspective”. In: The Ontology of Spacetime. Ed. by Dennis Dieks. Amsterdam: Elsevier, 2006, pp. 111–27. [37] Theodore Sider. “Quantifiers and Temporal Ontology”. In: Mind 115.457 (2006), pp. 75–97. [38] Tom Stoneham. “Time and Truth: The Presentism-Eternalism De- bate”. In: Philosophy 84.2 (2009), pp. 201–18. [39] Jonathan Charles Tallant. “Defining Existence Presentism”. In: Erkenntnis 79.3 (2014), pp. 479–501. [40] Michael Thompson. Life and Action. Cambridge, Mass.: Harvard University Press, 2008. [41] Giuliano Torrengo. “Ostrich Presentism”. In: Philosophical Studies 170.2 (2014), pp. 255–76. [42] Giuliano Torrengo. “The Grounding Problem and Presentist Ex- planations”. In: Synthese 190.12 (2013), pp. 2047–63. [43] Ludwig Wittgenstein. Zettel. Ed. by G.E.M. Anscombe and G.H. von Wright. Berkeley and Los Angeles: University of California Press, 1967. [44] Dean W. Zimmerman, ed. Oxford Studies in Metaphysics, Vol. 1. Oxford: Clarendon Press, 2004. [45] Dean W. Zimmerman. “Persistence and Presentism”. In: Philo- sophical Papers 25.2 (1996), pp. 115–26.

Carnap’s Logic of Science and Reference to the Present Moment

Florian Fischer

Abstract The important switch from the so-called old B-theory to the new tenseless theory of time (NTT), which had significant implications for the field of tense and indexicals, occurred after Carnap’s era. Against this new background, Carnap’s original inter-translatability thesis can no longer be upheld. The most natural way out would be to modify Carnap’s position according to the NTT; but this is not compatible with Carnap’s metaphysi- cal neutrality thesis. Even worse, Carnap’s work on measurement theory can be used to develop an argument in favour of the A-theory. I argue that there are tensed basic sentences which are needed in order to construct a tenseless system and thus cannot be translated without loss of meaning into tenseless ones (old B-theory) or made true by tenseless facts (NTT).

Keywords: Rudolf Carnap, Philosophy of Time, Tense vs. Tenseless Theory, A-Theory, B-Theory, New Tenseless Theory of Time

1 Carnap and Tense

This paper brings the work of Rudolf Carnap together with the modern debate about tense in the philosophy of time. It is an interesting fact that these fields have never been put together,1 despite the fact, or so I believe, that their content is deeply connected. The debate between so-called tensed and tenseless theories is a central issue in contemporary philosophy of time. ‘Tensers hold that grammatical tense is semantically irreducible, while detensers hold that tense is semantically reducible’ [69, p. 2]. Under the buzz phrase ‘tensed versus tenseless theory’, I subsume different philosophical positions about the reference to the present mo- ment. This divide places tensed theory, A-theory and indexicality on one side, and tenseless theory, B-theory2 and non-indexicality on the

Kriterion – Journal of Philosophy, 2016, 30(2): 61–90. http://www.kriterion-journal-of-philosophy.org c 2016 The author 62 KRITERION – Journal of Philosophy, 2016, 30(2): 61–90 other. I will go into the details of some of the positions later; for now, it suffices simply to set out the broad division into two camps. The tensers3 believe that the (firstly linguistic) reference to the present is meaning-constitutive. This reference can be encoded in the tense or as- pect4 of a sentence or expressed by an indexical like ‘now’ or ‘tomorrow’. The detensers want to get rid of this reference to the present, be it by translation (old B-theory) or by giving tenseless truth conditions (new tenseless theory of time, or NTT for short). A quick glance at the chronology of publication shows that the rele- vant philosophical work by Carnap took place significantly earlier than the switch from the old B-theory to the NTT. In 1926 Carnap published his Physikalische Begriffsbildung [16]. His Aufbau [12] is from 1928, and his considerations about protocol sentences are from 1932 [25]. In 1934, he published his main work in pure syntax [22], while by 1942 his se- mantic turn had taken place [15]. Prior’s Thank Goodness argument [60] was published in 1959, only four years before Carnap’s intellectual autobiography [14] and 20 years before Perry’s Essential Indexicals [58]. Mellor’s Real Time [49] was not published until 1981, and his Real Time II appeared as recently as 1998 [50]. A re-evaluation of Carnap’s work in this new light is important for at least two reasons: (a) Carnap’s position reveals the costs of the NTT. Not all of the old B-theoreticians can easily convert to the NTT, for the NTT is much too metaphysical for the likes of Carnap and makes too many concessions to the A-theory in accepting the impossibility of translation without loss of meaning. (b) The newer debate in the philosophy of time makes us aware of the internal tension in Carnap’s work. Carnap wanted to be metaphysically neutral, and thus systematically underestimated the implications of his own findings. In various places, for example, he contended that time has a special empirical status (e. g. [13], [24], [16, p. 14] and [27, p. 78]), but never explored the possible philosophical consequences of this.5

1.1 Extracting Carnap’s stance on tense

Before we can evaluate the impact of the newer developments in the philosophy of time for Carnap’s position, we have to ascertain the status of indexical concepts for his logic of science. Carnap’s early work up to Der logische Aufbau der Welt [12] differed in some important points from ideas he developed in Testability and Meaning [17] or his Philosophical Foundations of Physics [27]. So, the first goal of this paper is to provide Florian Fischer: Tensed Logic of Science 63 a rough reconstruction of Carnap’s thoughts on tense. Carnap upheld the inter-translatability thesis throughout his career: ‘This neutral attitude toward the various philosophical forms of lan- guage, based on the principle that everyone is free to use the language most suited to his purpose, has remained the same throughout my life’ [14, p. 18]. Carnap always believed that ultimately one can choose be- tween different languages.6 The logic of science, for example, can be based on a physicalist or a phenomenalist language,7 [14, p. 18]. These languages are inter-translatable. This is deeply connected with Carnap’s belief in conventionalism, the ‘philosophical position according to which the truth of a certain proposition [. . . ] is in some sense best explained by appeal to intentional human actions, such as linguistic stipulations’ [68, p. 169]. Carnap’s so-called principle of tolerance was ‘perhaps bet- ter called the principle of conventionality’ [15, p. 247]. For Carnap, it is only considerations of convenience (or pragmatics) that can decide in favour of one language over another [65, p. i]. Within this context, Carnap also dismissed indexicals as unessential. According to standard definitions, an indexical is a ‘linguistic expres- sion whose reference can shift from context to context’ [9]; alternatively, ‘An indexical expression is one whose extension varies with variation in features of its context of use, but which is otherwise rigid’ [42, p. 237]. Following Bar-Hillel, I take the term indexicals to include ‘I’, ‘now’, and ‘here’ as well as ‘this’ and ‘that’ [4]. Carnap believed that indexicals can be replaced by time and date specifications and the like, and that they should be so replaced to arrive at an intersubjective description of the world: ‘for science, it is possible and at the same time necessary to restrict itself to structure statements’ [21, p. 30]. Another main thesis endorsed by Carnap is metaphysical neutrality. This thesis stems from logical positivism and is closely connected to the ‘empirical sense’ criterion. To avoid ‘bad metaphysics’, Carnap always opted for metaphysical agnosticism. The empiricists/positivists claimed that the only source for our knowledge is the directly given, namely sense-data. Every concept of science should be reduced to the relevant sense data. Carnap’s Aufbau [12] from 1928 is a detailed execution of this agenda [75, p. 37]. All scientific statements should be able to be proven wrong (falsified) or right (verified) by reference to sense data. If successful, the Aufbau’s program would also show that, besides the positivist’s given, no other source of knowledge is needed [12, §5]. The program of the Aufbau is not to be understood as logically neces- sary. Quite the contrary, it includes a lot of systematic choices. Carnap 64 KRITERION – Journal of Philosophy, 2016, 30(2): 61–90 chose the object domain and decided to take an auto-psychological phe- nomenalist basis [12, §64], which means that, ultimately, the experiences of an individual subject lie at the basis of his constructional system. A constructional system ‘attempts a step-by-step derivation or “construc- tion” of all concepts from certain fundamental concepts, so that a ge- nealogy of concepts results in which each one has its definite place’ [21, p. 5]. In Carnap’s methodological solipsism, cultural objects are based in other minds, which are themselves based in physical objects, which again themselves are based in phenomenal ones via quasi-analysis,8 ac- cording to their order of epistemic priority.9 Carnap opted for the ‘inter- translatability’ [12, p. 57] of the physical and the phenomenological. He believed it to be possible to construct the physical objects via ‘quasi- analysis’ from a phenomenological basis: ‘According to the conception of epistemic priority in the Aufbau, the world of science was recoverable from the resources of individual epistemic subjects alone’ [75, p. 37]. Intersubjectivity was a main criterion for Carnap’s logic of science. He thought that indexicals were incompatible with intersubjectivity and thus devised a method for getting rid of them.

[E]ach scientific statement can in principle be so trans- formed that it is nothing but a structure statement. But this transformation is not only possible, it is imperative. For science wants to speak about what is objective, and what- ever does not belong to the structure but to the material (i. e. anything that can be pointed out in a concrete osten- sive definition) is, in the final analysis, subjective. One can easily see that physics is almost altogether desubjectivized, since almost all physical concepts have been transformed into purely structural concepts. [21, p. 29]

Carnap’s Logical Syntax of Language [22] transposed his previous work to the methodological level [43, p. 21]. Carnap did not claim that words do not have a meaning, but he systematically excluded the mean- ing and hence ‘[n]o reference to the meaning of the signs and expressions is made in logical syntax’ [47, p. 554]. Carnap also expelled indexicals in this so-called syntactical period, and proposed a translation scheme. The coordinate replacement thesis was the plan to replace ‘name-languages’ with ‘coordinate languages’ [21]. The replacement has to take place since ‘the method of designation by proper names is the primitive one; that of positional designation corresponds to a more advanced stage of science and has considerable methodological advantages over the former’ [14, p. Florian Fischer: Tensed Logic of Science 65

12].10 Carnap’s method of uniquely designating structural descriptions from the Aufbau [12, sec. 16] is applied in the Logical Syntax of Language in order to eliminate indexicals in favour of non-indexical descriptions. In chapter B of Logical Syntax of Language [22] Carnap is concerned with the ‘syntax of any language’. There he completely dismisses index- icals such as ‘now’: In case of sentences in which words like ‘I’, ‘you’, ‘here’, ‘now’, ‘to-day’, ‘yesterday’, ‘this’ (in the sense of “the one present”) and so forth occur, the logical character is not only dependent upon the preceding sentences, but also upon the extra-linguistic situation — namely, upon the spatio- temporal position of the speaker. In what follows, we shall deal only with languages which contain no expression dependent upon extra-linguistic fac- tors. The logical character of all the sentences of these lan- guages is then invariant in relation to spatio-temporal dis- placements; two sentences of the same wording will have the same character independently of where, when or by whom they are spoken. In the case of sentences having extra-syntactical dependence, this invariance can be attained by means of the addition of person-, place-, and time- designations. [22, p. 168]. But as Carnap’s major disciple Yehoshua Bar-Hillel remarks, it ‘is quite clear that this qualification restricts highly the applicability of Car- nap’s general syntax to ordinary languages. The overwhelming major- ity of the natural language sentences are indexical, i. e. dependent upon extra-linguistic factors’ [5, p. 524]. Indeed, not long after the publication of Logical Syntax Carnap came to the conclusion that the one-sided restriction to syntax may have been fruitful, but was also very austere: ‘this method studies only the forms of the expressions, not their meanings’ [22, p. 52]. A calculus can be interpreted and applied to objects and the syntax must thus be comple- mented with a semantics. Taking semantics into account restricts the conventionalist freedom, however, since possible interpretations have to be considered [43, p. 21]. Carnap did indeed become more interested in the meaning of expressions after this ‘semantic turn’, but he did not lift the ban on indexicals. Besides this, Carnap was concerned with time in the context of mea- surement and with indexicals in the context of the protocol sentence 66 KRITERION – Journal of Philosophy, 2016, 30(2): 61–90 debate. Both will be discussed later in the paper. For now we need only observe that Carnap shunned indexicals throughout his career. He either systematically excluded them, or voted for replacing them with allegedly more reputable time-designations. Carnap thus clearly belongs in the camp of the (old) B-theory, believing that tensed sentences can be translated without loss of meaning into tenseless ones.

1.2 Translatability of tensed sentences and the NTT’s metaphysical commitment The opposing view, that the meaning of a tenseless sentence differs from the meaning of its tensed counterpart, did have some proponents even in Carnap’s time. From within Carnap’s close social environment, this posi- tion was maintained by Moritz Schlick. The so-called protocol sentences debate within the Vienna Circle revolved exactly around this topic.11

If I make the confirmation “Here now blue”, this is not the same as the protocol statement “M. S. perceived blue on the nth of April 1934 at such and such a time and such and such a place.” The latter statement is a hypothesis and as such always characterised by uncertainty. The latter statement is equivalent to “M. S. made . . . (here time and place are to be given) the confirmation ‘here now blue.”’ And that this assertion is not identical with the confirmation occurring in it is clear. [2, p. 226]

Protocol sentences were supposed to be the rock on which knowl- edge, and especially scientific knowledge, should be built. They had to be objective, intersubjective and free of indexicals, as they ought not to depend on the individual person/scientist. In Uber¨ Protokolls¨atze [19] Carnap thus opted for the supposedly objective approach of date and time indication instead of the indexical ‘now’. Schlick, however, argued that these protocol sentences cannot be justified. The sentences that are needed to build a system of knowledge — sentences such as ‘M.S. perceived blue on such and such date at such and such time at that lo- cation’ — are only hypotheses. They are not the immediately given, the positive of the positivists. The only things which are given, according to Schlick, are expressed in sentences like ‘Here now blue’ which he calls Konstatierungen (confirmations). Konstatierungen are not apt to build a system of knowledge, as they cannot even be written down: ‘A gen- uine confirmation cannot be written down, for as soon as I inscribe the Florian Fischer: Tensed Logic of Science 67 demonstratives “here”, “now”, they lose their meaning’ [2, p. 226]. Thus a dilemma arises for the foundations of scientific knowledge. Schlickian confirmations are available but insufficient, whereas Carnapian protocol sentences would be sufficient but are not available. The participants of the Vienna Circle became mired in the debate about the status of the protocol sentences. No agreement could be reached, and the question was put on hold and then never resumed [43, p. 16]. This is a historical fact, not a systematic insight, and the systematic quarrel is still not settled today. It is nonetheless remark- able that Schlick, Carnap’s contemporary, had already made the case for irreducible indexicals12 that are not replaceable by times and dates: ‘Neither can they be replaced by an indication of time and place, for as soon as one attempts to do this, the result, as we saw, is that one unavoidably substitutes for the observation statement a protocol state- ment which as such has a wholly different nature’ [2, p. 226].13 If Schlick is right, then tensed and tenseless sentences are not on a par. Tensed sentences are not incomplete sentences at all but, quite to the contrary, contain a special form of knowledge (Erkenntnis14) that cannot be in- corporated in tenseless sentences. Interestingly, the fatal blow for the old B-theory occurred much later. The old B-theoreticians had held a translatability thesis: All tensed sentences are translatable without loss of meaning into tenseless sen- tences. Frege had proposed a date indication analysis, stating that the tensed sentence ‘It is raining now’ actually means, say, ‘It is raining at Thursday 13 May 2014’ [36, p. 297] or [35]. Russell opted for a token- reflexive analysis, according to which the sentence should be translated as ‘It is raining at the time point that is co-temporal with this utterance’ [66, p. 108]. Prior [60] and Perry [58] famously stated that reference to the present moment is both important for our actions and not translatable without loss of meaning into tenseless concepts and sentences. Today, the ir- reducibility of tensed sentences and beliefs has been accepted all but universally,15 and ‘recent defenders of the tenseless view have come to embrace the thesis that tensed sentences cannot be translated by tense- less ones without loss of meaning’ [56, p. 58]. Prior claimed that reference to the present is relevant for actions and that tensed sentences cannot be translated without loss of meaning. His example is the relief or joy someone feels, when, say, an important test is completed. According to Prior, the decisive factor for feeling the joy is that one believes that the test is now completed. It is not enough, 68 KRITERION – Journal of Philosophy, 2016, 30(2): 61–90 say, to believe that the test ends at 2:00 p. m. and that 2:15 p. m. is later than 2:00 p. m., because all that is known before the test is taken but doesn’t trigger the joy. One says, e. g. “Thank goodness that’s over!”, and not only is this, when said, quite clear without any date ap- pended, but it says something which it is impossible that any use of a tenseless copula with a date should convey. It cer- tainly doesn’t mean the same as, e. g. “Thank goodness the date of the conclusion of that thing is Friday, June 15, 1954”, even if it be said then. (Nor, for that matter, does it mean “Thank goodness the conclusion of that thing is contempora- neous with this utterance”. Why should anyone thank good- ness for that?) [60] Perry uses a different example to argue for the same conclusion: A tardy professor ‘who desires to attend the department meeting on time, and believes correctly that it begins at noon, sits motionless in his office at that time. Suddenly he begins to move. What explains his action? A change in belief. He believed all along that the department meeting starts at noon; he came to believe, as he would have put it, that it starts now’[58, p. 4]. Prior’s and Perry’s arguments changed the debate radically; after- wards, virtually nobody believed that tensed sentences can be translated into tenseless sentences without loss of meaning. Mellor thus proposed another method instead: he stated that tensed sentences can be given tenseless truth conditions. In his first attempt, published as Real Time [49], Mellor understood the meaning of a tensed sentence as a function from utterances to truth conditions. Due to strong critique16 he later changed his position. In Real Time II [50] the meaning of a tensed sentence is a function from time points to truth conditions. The new B-theoreticians still call their view tenseless, but this tenselessness now concerns the structure of the world. The problem [. . . ] is to determine whether this aspect [i. e. being tensed] is a feature of reality that is described or merely a feature of the statement by which it is described. Is reality itself somehow tensed [. . . ] or is it merely that we describe a tenseless [. . . ] reality from a tensed [. . . ] point of view? [34, p. 261] The shift from the old to the new tenseless theory was thus a shift from philosophy of language to metaphysics.17 Old B-theoreticians Florian Fischer: Tensed Logic of Science 69 claimed that tensed sentences are either incomplete (they need the ad- dition of an explicit time and date, like a 2-place relation needs a second relatum) or are linguistically on a par with tenseless ones (the tense being just a fa¸con de parler). The truthmakers of the sentences did not really play a role. True, the position one took regarding tensed sentences was de facto also often mirrored in the position one held regarding the nature of time,18 but there did not need to be a systematic link between the two: ‘Presentism and becoming have also been associated with the idea that tensed language does not have tenseless truth conditions. However, this is not a necessary connection’ [45, p. 326]. It might be controversial, but I think that the NTT wedded lan- guage to metaphysics. Nowadays, one can only truly be called a B- theoretician if one holds a tenseless world view.19 Mellor [50] claims that tenseless facts are not only sufficient as truthmakers for tensed sen- tences, but necessary. This can be seen as a cost of the NTT20, since it might deter philosophers of language who shun metaphysics from the NTT. Carnap, for example, systematically excluded semantics during his syntactic period [22], while Otto Neurath in Protokolls¨atze [53] and Radikaler Physikalismus und wirkliche Welt [54] opted for the dismissal of any reference to the language-external ‘reality’ and the restriction of philosophical attention to language-internal questions [3, p. 146 et sqq.]. Influenced by Neurath, Carnap (e. g. [25]) focused on coherence inside a language system instead of truth as correspondence with the ‘world’ [43, p. 16].21 Mellor’s NTT is not an option for such philosophers, who don’t believe in facts (whether they be tensed or tenseless) or who want to be metaphysically neutral. It is thus not available to Carnap, since it is compatible neither with his metaphysical neutrality thesis nor with his inter-translatability thesis.

2 Inter-Carnapian tensions and Carnap’s unintended argu- ment for the tensed theory

As we have seen, Carnap’s inter-translatability thesis cannot be held in the universal form. The old B-theory and with it the hope of translata- bility without loss of meaning between tensed and tenseless sentences had been abandoned after Prior’s and Perry’s famous arguments. It is, however, also not possible to transfer Carnap’s work to the NTT, which is the successor theory to the old B-theory. The NTT may be on the tenseless side of the divide but its specific metaphysical character con- tradicts Carnap’s much-beloved metaphysical neutrality thesis. This is 70 KRITERION – Journal of Philosophy, 2016, 30(2): 61–90 no surprise, however. In 2.3 I will sketch a transcendental argument in favour of the A-theory, which relies on Carnap’s considerations about time measurement (2.1) and Russell’s achievements in the field of index- icals (2.2). The argument also reveals tensions within Carnap’s work, which help to explain why he and the NTT form such an odd couple.

2.1 Carnap on time measurement

Carnap laid down some interesting thoughts about time measurements in Philosophical Foundations of Physics [27], later reprinted as An Intro- duction to the Philosophy of Science [11]; these thoughts go back to his Physikalische Begriffsbildung [16]. Duration is a quantitative magnitude, more precisely an extensive magnitude. According to Carnap, extensive magnitudes can be measured with the aid of three-rule schemas, consist- ing of (1) The rule of equality, (2) The rule of additivity, and (3) The unit rule.22 ‘Three-rule schemas apply to situations in which two things can be combined or joined in some way to produce a new thing, and the value of magnitude M for this new thing will be the sum of the values of M for the two things that were joined’ [27, p. 77]. Carnap, following Carl Gustav Hempel, insisted that combination refers to a physical operation in this context, which has to be distinguished sharply from arithmetical addition [27, p. 72]. The measurability with a three-rule schema applies to all extensive magnitudes, but time intervals have a special status because of their physical peculiarities: ‘We cannot manipulate time intervals in the way we can manipulate space intervals, or, more accurately, edges of solid bodies representing space intervals. There are no hard edges of time that can be put together to form a straight line’ [27, p. 78]. Carnap tried to acknowledge the special status of time intervals by the introduction of a conceptual scale. In the context of time measurements he understood ◦ in the rule of additivity T (a ◦ b) = T (a) + T (b), with T being the temporal length, as a conceptual operator. Both other rules (equality and unit) are grounded in periodic pro- cesses, according to Carnap. Carnap distinguished two sorts of period- icity: ‘In the weak sense, a process is periodic simply if it recurs again and again and again’ [27, p. 80]. The strong sense requires ‘that in ad- dition to being weakly periodic, it is also true that the intervals between successive occurrences of a certain phase are equal’ [27, p. 80]. Prima facie one would expect that time measurements need strong periodic processes. There is, however, a problem with this requirement, which Florian Fischer: Tensed Logic of Science 71

Carnap had clearly spotted: ‘We cannot know that a process is periodic in the strong sense unless we already have a method for determining equal intervals of time’ [27, p. 80]. This is a vicious situation: we need the rules of equality and unit to build a system of time measurement, but we need a system of time measurement to establish the rules of equality and unit. Or so it seems. Carnap proposed a solution to this conundrum which is centred on the equivalence of processes. He elucidated process equivalence with the example of the swinging of a certain short pendulum P, which is compared with the swinging of a longer pendulum P0. ‘In view of the fact that the periods of the two pendulums are not equal, how do we compare the two? We do it by counting the swings of both pendulums during a longer time interval. [. . . ] We may observe, however, that the coincidence is not exact. After ten swings of the short pendulum, the long one already started on its seventh swing’ [27, p. 82]. Note that ‘already started on its seventh swing’ only makes sense if the two intervals started at the same time. I will come back to this; let us first go through Carnap’s resolution of the alleged vicious circle. To handle the case of the not-exact coincidence, Carnap proposed to observe the pendulums for a longer time interval: ‘In this way we can sharpen our comparison as much as we please’ [27, p. 82]. On this basis he can now specify process equality: ‘If we find that a certain number of periods of process P always match a certain number of periods of process P0, we say that the two periodicities are equivalent’ [27, p. 83]. Process equality alone does not suffice as a solution to the conun- drum, however; an empirical fact is also needed, namely that there is one ‘large class of periodic processes that are equivalent to each other in this sense’, and that ‘[a]s far as we know, there is only one large class of this kind’ [27, p. 83]. At this point Carnap’s conventionalism kicks in: ‘We cannot say that the pendulum is the “right” choice as the basis for our time unit and my pulse beat the “wrong” choice’ [27, p. 83]. Carnap equipped us with a method for measuring duration without pre- supposing equal temporal length. This enables us to measure time as a quantitative concept.

2.2 An unlikely ally for the tensed theoreticians: Russell

Russell provides a valuable source for our study of tense and indexicality. In 1940 Russell was arguing along the same lines as Carnap. He claimed in Inquiry into Meaning and Truth that indexicals are ‘not needed in any 72 KRITERION – Journal of Philosophy, 2016, 30(2): 61–90 part of the description of the world, whether physical or psychological’ [66, p. 108]. Later, in 1948, Russell explicitly changed his mind and thus objected to Carnap’s position. Russell was now concerned with indexicals because of their importance for knowledge and especially sci- entific knowledge: they are indispensable, he claimed, ‘in stating the basis of empirical knowledge in immediate experience’ [31, p. 119]. Rus- sell posited the following four characteristics of indexicals in his book Human Knowledge [31, p. 123]:

1. Coordinate replacement Indexicals, as well as strict names, can be progressively replaced by coordinate descriptions, but only up to a certain point. 2. Indispensability Indexical expressions cannot be entirely elimi- nated. They are indispensable to human discourse, including any science that requires human observation. 3. Interdefinability Each indexical expression can be defined in terms of another (or a combination of others). 4. Reducibility All indexical expressions can be reduced to one basic type, although this basic type need not be one in particular.

Scientific concepts must ultimately terminate in ostensive definitions, according to Russell, and thus ‘indexicals are not completely eliminable’ [31, p. 119]. Russell’s coordinate replacement thesis for indexicals goes back to Carnap’s Logical Syntax of Language [22]. Contrary to Carnap, however, Russell thought that this program works only up to a certain point: ‘We cannot wholly dispense with proper names [indexicals] by means of coordinates’.23 Farrell-Smith is very explicit about the limita- tions that Russell imposes on the coordinate replacement thesis:

Coordinates describe a point in space-time. They locate it by means of reference to axes and distance from the origin of axes. But, Russell asks, how do we designate the axes and the origin? We cannot go on indefinitely giving a descrip- tion of the origin of each system in terms of another system. Ultimately we must be able to say, ‘This is the origin.’ In other words, we must be able to name the origin, in contrast to merely describing it. [31, p. 119]

We can apply Russell’s findings on space straightforwardly to the case of time. We need a way of referring to the point of origin outside of Florian Fischer: Tensed Logic of Science 73 the time and date system. Only then can such a system be established. Without it, the term ‘point in time’ is meaningless: if we do not have a way of ‘knowing some places otherwise than by latitude and longi- tude, latitude and longitude become unmeaning’ [67, p. 77]. Unless the whole system should become free-floating, we ‘must have some method of identifying a place [a time] without mentioning the coordinates’ [67, p. 78].

Then, since the assignment of coordinates requires as- signing an origin and axes, the question arises as to whether the origin can be defined. [Russell] answers that it must be defined by reference to something observable. Theoretical constructs like the sun obviously will not do. [31, p. 119]

The limitations this introduces to the time case are pretty obvious. ‘Theoretical constructs’ like the Big Bang cannot serve as the origin; rather, we need something directly observable. ‘[U]nless we already have some non-descriptive way of fixing this framework, i. e. some way of “naming” its origin, we face a regress that detaches scientific knowledge from its empirical basis’ [31, p. 119].

2.3 The argument in favour of the A-theory We have seen that Carnap’s original inter-translatability thesis had to be dropped due to the developments in the philosophy of tense. Section 1.2 argued that Carnap can also not be on the side of the NTT, the successor theory of the old B-theory. A tension seems to arise, since some of Carnap’s statements clearly place him on the tenseless/B-theoretic side of the divide, as we have seen in 1.1. A closer inspection will reveal that the incompatibility of Carnap’s position with the B-theory is not surprising.24 In his considerations about time measurement, Carnap emphasised that the term “longer” does not have a meaning without the complete three-rule schema: ‘We do not know what you mean by ‘longer’. We are trying to lay down rules for the measurement of time so that we will be able to give meaning to the term “longer”’ [27, p. 81]. Parallel to this, I will argue that time and date indications do not have a meaning without a tensed anchor point. If the argument goes through, it will show that the tensed and tenseless approaches are not on a par. The asymmetry towards the tensed is not in line with Carnap’s inter-translatability theses, but it fits well with what he says in various 74 KRITERION – Journal of Philosophy, 2016, 30(2): 61–90 other places (e. g. [13], [24], [16, p. 14] and [27, p. 78]) where he defends a special status for time. Thus, it would hint at the inner tension within Carnap’s work. This tension cannot be dissolved by identifying different periods in Carnap’s work. Carnap first developed his thoughts about time measurement in a small volume called Physikalische Begriffsbildung [16] from 1926, a full forty years before Philosophical Foundations of Physics [27]. It is thus safe to say that he held these views throughout his career. I will first go through the premisses, then I will sketch25 the argument and comment on it.

(Presup.): I restrict the argument to the debate between A- and B-theory, a restriction which might be questioned. If the argument goes through it would help the A-theorists a good deal as it does not rely on the experience of time, which is as often consulted as an aid for the A-theory as it is problematic [39].

(Carnap 1): Carnap thought that in ‘the case of sentences having extra-syntactical dependence, [. . . ] invariance can be attained by means of the addition of person-, place-, and time-designations’ [22, p. 168]. He thus believed that the indexical ‘now’ can easily be replaced by a B-theoretic time-designation and should be replaced.

(Carnap 2): Carnap emphasised the difference between time and space, as ‘We have two separate events, each with a certain length of time, but there is no way to bring them together. [. . . ] we cannot shift events around as we can shift the edges of physical objects’ [27, p. 78]. Time plays a special role for Carnap.

(Carnap 3): Carnap showed how to reach a definition of duration via the ‘one large class of periodic processes that are equivalent to each other’ [27, p. 83]. This premise has the form of an implication. If an origin is supplied, Carnap’s specification of duration can be used to build a B-theoretic system of times.

(Russell 1): Russell claimed that ‘[w]e cannot wholly dispense with proper names [indexicals]’ [67, p. 78]. Russell thought that indexicals were interdefinable. Given some (suitable) indexical basis we can define the remaining indexicals. This is a systematic point for Russell, i. e. he doesn’t claim that there is one particular indexical which is the objective Florian Fischer: Tensed Logic of Science 75 basis: Russell’s claim can rather be understood the other way around, namely that we can never completely leave the realm of the indexical.

(Russell 2): Russell argued that we cannot go on indefinitely giving a description of the origin of each system in terms of another system. Ultimately we must be able to say, ‘This is the origin’ [31, p. 119].

(B-theory): A B-theoretic time specification consists of a time and date indication.

(Systematicity): A time and date specification only makes sense within a given system of time. For example ‘It rained at three o’clock on the 7th of April’ only makes sense in respect to a calendaric system, like ours.

(Argument - short): The shortest way to set up the argument in favour of the tensed/A-theory side of the divide is to take (Carnap 2) and (Russell 1) and conclude that ‘now’ is the basic indexical. This is the shortest but arguably also the most uncertain form of the argument. (Russell 1) clearly states that we cannot wholly dispose of in- dexicals. It is unclear however if (Carnap 2) is really enough to establish that time is fundamental in the sense required. If time is fundamental and we cannot wholly dispense of indexicals, then ‘now’ has to be the basic indexical.26 The argument is valid but maybe not sound, i. e. some of the premises may be false. The premise (Carnap 2) is its potential weak spot. Acknowledging a special role for time is not enough; rather, the fundamentality of time must be established. If this short argument goes through it can easily be extended to contradict (Carnap 1). Since ‘now’ is the basic indexical it is thus not dispensible; but this is exactly the opposite of what (Carnap 1) claims. Note that Russell’s considera- tions from Human Knowledge are not sufficient to set up the argument, since Russell did not believe in any priority among the indexicals. A longer version (Argument - long): (Russell 2) states that each system needs an external anchor. As an instance of that, a system of time needs an external anchor. Now this anchor can either be spec- ified indexically/A-theoretically or non-indexically/B-theoretically. A B-theoretic specification consists of a time indication (B-theory), but this in turn only makes sense within a given system of time (Systematic- ity). So, on pain of circularity, the origin of a system of time cannot be specified B-theoretically. It thus has to be specified A-theoretically. 76 KRITERION – Journal of Philosophy, 2016, 30(2): 61–90

The heart of (Argument - long) is that a system of time cannot be specified by a date and time indication on pain of circularity. A time and date indication only makes sense in reference to an existing system of time and thus cannot be used to build a system of time. Of course, a pre-existing system of time could be used to build up another system of time. I could, for example, use the calendar system of the ancient Greeks with the original Olympic Games as the origin, to specify our calendar system with the birth of Christ as the origin.27 But ultimately one has to come to an external anchor, and this is what (Russell 2) states. As this is a systematic point, not a mere contingency, it justifies the modal claim that a system of time cannot be specified by a time and date indication (ultimately). This modal strength then justifies the claim that the origin (ultimately) has to be given in indexical terms. As we are talking about a system of time, the indexical in question is ‘now’, i. e. the A-theoretic way of specifying the origin. This argument can easily be extended to contradict (Carnap 1). As a system of time needs an indexical anchor, we cannot completely dis- pose of indexicals (if we want to set up a system of time at all, that is). But there is also a constructive part. Carnap’s construction of du- ration via equivalent processes may help us to build an intersubjective system of temporal location, once we have amended it with a tensed A-theoretic origin. This actually is Carnapian in spirit. In his exam- ple from Philosophical Foundations of Physics [27, p. 82], the scientist starts both pendulums in his present and thus both processes start at the same time. To sum up, the construction of any time and date system requires an anchor point, prior (constructively prior, not temporally prior) to this system. This anchor can only be understood as tensed, or so I have argued. If the argument goes through then tensed and tenseless theories of time are not on a par. Granted, one could still choose between the different tenseless theories by convenience, but a tensed anchor is mandatory for there to be a system of time at all.28 Any system of time order, be it metrical or topological, needs to be pinned to reality, so to speak, in order to have empirical content.29 ‘With tolerance in place, Carnap is prepared to imagine non-empiricist languages, though of course he thinks they are very unwise’ [30]. Thus Carnap also has to deem a purely tenseless system of time, without an tensed anchor, ‘very unwise’. The argument is not only about statements occurring in scientific theories, but about the prerequisites for establishing any B-theoretic Florian Fischer: Tensed Logic of Science 77 time order. This may not be on Carnap’s agenda, but still, I think, it is rooted in his systematic thoughts about time measurement. Carnap’s early characterisation of a time topology might include a short cut to the result that A-theoretic simultaneity is a precondition of a B-theoretic time order,30 as Carnap explicitly bases physical simultaneity on local phenomenological simultaneity. In Physikalische Begriffsbildung [16, p. 37], Carnap defined simultaneity (i. e. when two events get the same value of time) in the following way: Two events are physically simultaneous if they are perceived together. There Carnap explicitly states that physics presupposes phenomenological simultaneity as a determinable basic re- lation [16, p. 38]. Be that as it may, right now I am concerned with a more general point. Every B-theoretic system of time order, be it a topology or a metric, needs an anchor outside the system in order to be built in the first place. To arrive at a numeric value for a (B-theoretic) time and date indication, we need to fix an initial point and an ongoing process to specify the time-wise distance to this initial point. Carnap himself writes: ‘We don’t know of an initial point of the time series. An arbitrarily chosen time point has to be fixed as the point of origin of the time scale, as it is done in the various calendar systems (first year; first day of the year).’31 The origin thus cannot be specified by a time and date indication, since it is needed to set up a calendar system in the first place. In order to be able to order events in a calender system, people at some point needed to say ‘we start counting years now’, ‘this is year one’. The earlier/later relation is dependent on the A-series of past/now/future, and thus tensed sentences can neither be translated without loss of meaning into tenseless ones nor can they be given tense- less truth conditions. The argument I have sketched does in no way question the usefulness of a tenseless system of times and dates; it seeks only to show that a B-theoretic time and date indication is meaningless without an A-theoretic anchor, just as the term ‘longer’ is meaningless without a system of time measurement. Carnap and Russell were concerned chiefly with epistemological ques- tions, but the argument can also be given a more metaphysical32 gloss: ‘[T]he philosophy of A-time or B-time, perhaps more than any other area, has shown the continuing relevance of the idea that natural language is, in some carefully qualified sense, a guide to the nature of reality’ [41, p. 4]. After all, it was the tenseless theoreticians who strengthened the link between language and ontology by adhering to the NTT, so now 78 KRITERION – Journal of Philosophy, 2016, 30(2): 61–90 they have to face the music: Our system of knowledge is rooted in irre- ducible tensed sentences, from which tenseless date and time indications can be derived. This is not a choice of convenience but something that is necessitated by the requirements of construction. If our knowledge has something to do with the structure of the empirical world, how could there be only tenseless facts in the empirical world? To clarify where the onus of proof falls: The tenseless theoretician acknowledges the ir- reducibility (i. e. the non-translatability and indispensability) of tensed sentences but thinks she can still dispense with tensed facts by posit- ing tenseless facts as truthmakers. The existence of tenseless facts is a heavyweight ontological claim, according to Chalmers’s categorisation in [28]. The B-theoreticians acknowledged the necessity of tensed beliefs for our actions. If now the existence of a system of tenseless earlier/later depends on the A-series of past/present/future, as I have tried to show, then the odds for tenseless facts as truthmakers for empirical sentences are bad.33 However, this is not to deny the utility of a tenseless system of times and dates. Carnap made an important contribution on how to construct such a system, namely by using periodic processes and, most conveniently, the class of equivalent processes.

3 Concluding remarks

This paper focused on the interrelations between the modern philosophy of time and Carnap’s work. Carnap held an inter-translatability thesis throughout his career. He believed that, ultimately, one can choose be- tween different languages, because one can translate sentences between different languages, such as the physicalist’s or the phenomenalist’s lan- guage, without loss of meaning. This includes the translation of indexi- cals into time, date and name indications without loss of meaning. Exactly the same translatability of tensed sentences into tenseless counterparts was adhered to by the old B-theoreticians. Nowadays, the old B-theory has been given up for good. After Prior’s and Perry’s famous arguments, virtually no one now champions the old B-theory. Carnap’s inter-translatability thesis can no longer be upheld. The NTT, founded by Mellor, is the centerpiece of modern tenseless theories: but Carnap cannot stomach the NTT, since it is too metaphysical for him. According to Mellor, tenseless facts and only tenseless facts are apt truth- makers for tensed sentences. This contradicts Carnap’s metaphysical neutrality thesis. It is no surprise that Carnap and the NTT do not fit well together. To Florian Fischer: Tensed Logic of Science 79 show this, I have tried to extract an argument against the tenseless the- ory out of Carnap’s own remarks concerning time measurement. Carnap devised a clever way to measure duration as a metrical property, without succumbing to the lurking vicious circle. To build a system of times and dates, an origin must also be specified. Any B-theory requires such a system of time: the old B-theory on the level of language, and the NTT on the level of truth-makers. On pain of circularity, the origin cannot be specified B-theoretically and thus must be specified A-theoretically. This is backed up by Russell, one of the most prominent old-B-theoreticians, who claimed that indexical expressions cannot entirely be eliminated. A tenseless system of time and date indications requires a tensed anchor point to have empirical content. This not only shows that Carnap’s ideas do not fit well with the NTT, but also that there are pre-existing tensions within Carnap’s work. On the one hand Carnap wanted to get rid of all indexicals in his quest for intersubjectivity; on the other hand he was well aware that ‘[w]e cannot manipulate time intervals in the way we can manipulate space intervals’ [27, p. 78].

Acknowledgements

Parts of this paper were written during a research stay in Oxford fi- nanced by the DAAD. I’m very grateful for their support. Earlier versions of this paper were presented at the Interchair Colloquium in Bonn in 2014, the Tensed vs Tenseless Theory symposium (http://tense- less.weebly.com) at the SOPhiA conference in Salzburg 2014, and the Be- ing in Time conference (http://s-p-o-t.weebly.com/being-in-time.html) in Bonn 2016. I would like to thank the audiences there for enjoy- able and fruitful discussions. I would also like to thank Thomas M¨uller and his group in Konstanz, to whom I presented the paper in 2016. I have benefited a great deal from the SPoT discussion groups (http://s- p-o-t.weebly.com/events.html) in Bonn, and in particular I am deeply grateful to Sonja Deppe, Cord Friebe, Johannes Gr¨oßland Thorben Petersen. Maren Br¨autigam,Toby Friend, Caro Haupt, Stefan Heidl, Ludger Jansen, Martin Pickup, Matthias Rolffs and Niko Strobach all helped to improve the paper, and I am very grateful to them all. 80 KRITERION – Journal of Philosophy, 2016, 30(2): 61–90

Notes

1 I know of one paper which contains the words ‘Carnap’ as well as ‘tense’, but it has nothing to do with our topic: Arthur Prior’s example just happens to be ‘Professor Carnap will fly to the moon’ [59, p. 268]. In addition, Arthur Pap [57] speaks of ‘tense versus tenseless’ in the context of Carnap’s Testability and Meaning [17] but he conflates tense with time: ‘tensed, and hence time-referent form’ [57, p. 565]. As will become clear later, in the debate in the philosophy of time both sides agree that there is some kind of time reference; they disagree, however, about whether this essentially involves a reference to the present (tensed theory) or not (tenseless theory). 2 ‘The old B-theory says that tensed/indexical sentences are tenseless/non- indexical sentences in disguise, and hence that tensed sentences have tenseless truth conditions. The new B-theory denies that tensed/indexical sentences are tenseless/non-indexical sentences in disguise, but agrees that tensed sentences have tenseless truth conditions’ [69, p. 11]. 3 According to Peter Ludlow, ‘tensers think that propositions (or in any case bear- ers of truth) shift in truth-value over time [. . . ], while detensers put a time index in propositions and argue that propositions are anchored to a time [. . . ] in such a way that the proportions are eternal’ [46, p. 691]. As so often happens, in the debate between tensers and detensers the devil lies in the details. Ludlow [46] gives a good overview of the possible positions and their problems. For our purpose it is sufficient to get clear on the broader picture. In using tensed talk, for detensers ‘we are just talking about a series of tenselessly existing events or- dered by the earlier-than/later-than relation’ [46, p. 690], whereas for tensers ‘we are talking about some important temporal feature of the world (for example a tensed fact — like the fact that it rained yesterday — that currently obtains)’ [46, p. 690]. I will switch freely between the terms ‘tensed theory’, ‘tensers’, and ‘A-theory’ (as well as their counterparts) in this paper; whenever a specific linguistic or ontological reading is meant, I’ll make this clear. 4 Many of the features which traditionally have been assigned to tense by linguists now are considered aspectual. ‘Tense and aspect are, to be sure, closely related: both have to do with time, and both are, generally speaking, expressed grammat- ically by modifications of the verb’ [40, p. 2–3]. Aspect has long been neglected outside linguistics. Antony Galton remarks that Prior had worked out a tense logic in 1955 [61], the idea of which had already been stated by Findlay in 1941 [33], and yet his own logic of aspect was published as recently as 1984. 5 Carnap’s discussion with Einstein about ‘the Now’ may be a good illustration of this attitude. ‘Once Einstein said that the problem of the Now worried him seriously. [. . . ] But I definitely had the impression that Einstein’s thinking on this point involved a lack of distinction between experience and knowledge. Since science in principle can say all that can be said, there is no unanswerable question left’ [14, pp. 37–38]. It seems that Carnap thought that there was just no need to wonder further. 6 ‘This neutral attitude toward the various philosophical forms of language, based on the principle that everyone is free to use the language most suited to his pur- pose, has remained the same throughout my life. It was formulated as “principle of tolerance” in Logical Syntax and I still hold it today’ [14, p. 17]. Carnap’s original formulation of the Principle of Tolerance runs as follows: ‘It is not our Florian Fischer: Tensed Logic of Science 81

business to set up prohibitions, but to arrive at conventions’ [22, p. 51]; or, a bit later in the same book, ‘In logic there are no morals. Everyone is at liberty to build his own logic, i. e. his own form of language, as he wishes’ [22, p. 52]. This famous principle is not quite the same as the inter-translatability thesis as the latter is a prerequisite of the former. Only if the languages are inter-translatable may we freely choose between them. Note that the other direction doesn’t hold: one can think of different languages as inter-translatable and still be an elimina- tivist. Holger Andreas claims that this is the stance adopted by Carnap in his Aufbau [12]. Carnap’s goal was to provide rules for translating sentences con- taining non-basal concepts into sentences containing only basal concepts. The non-basal concepts are then eliminated in favour of the basal ones [1, p. 43]. 7 According to phenomenalism, physical objects are not themselves given but ‘are reducible to or definable in terms of the occurrence and obtainability of’ [7] sensory experience. Whereas ‘the thesis physicalism maintains that the physical language is a universal language of science—that is to say, that every language of any sub-domain of science can be equipollently translated into the physical language’ [22, p. 320]. 8 Carnap’s (in)famous method of quasi-analysis constructs physical objects from the contents of elementary experiences, which he took to be unanalysable and holistic. [1], [48] and [32]. 9 Here it is important for us to distinguish the metaphysical project from the epis- temic, as Carnap wanted to stay metaphysically neutral. ‘This epistemological reading is compatible with Carnap’s very strict exclusion of questions of ontology as bad metaphysics: the choice of the basis is a matter of choosing a language’ [55, p. 2]. 10 Carnap’s own example of color nicely elucidates this point. ‘In physics, we ap- parently have a property description when the color names (“blue”, “red”, etc.) are used. In present-day physics, descriptions of this kind are nothing but ab- breviations, since they presuppose wave theory and since the color names can be translated into expressions of this theory (i. e. rates of oscillation). However, formerly, these property descriptions revealed the incomplete character of the theory of light, since they were not transformable into relation descriptions.’ [21, p. 21]. 11 For an introduction to the protocol sentences debate, see [74, p. LVI]. This volume also features the original papers by Carnap and Schlick in chapter 5. 12 Of course this claim by Schlick is not without its own prehistory. Schlick’s work, however, is far less philosophically reprocessed than one would assume, given his status as founder of the Vienna Circle [72, p. 9]. 13 An observation statement is a statement expressing a direct observation. Carnap understood direct observation as perception that is unaided by technical instru- ments and inferences [27, Ch. 23]. For criticism of this characterisation see [1, ch. 2.1]. 14 Schlick’s paper is consequently called Das Fundament der Erkenntnis.[71]. 15 According to Cord Friebe, Sebastian R¨odl[64] may be “the village of indomitable Gauls” with respect to this claim [38, ch. A.2.1]. 16 A discussion of the theory in Mellor’s Real Time can be found in [56]. There, advocates as well as enemies of the New Theory of Time have their say. 82 KRITERION – Journal of Philosophy, 2016, 30(2): 61–90

17 I take the old B-theory to be metaphysical neutral, if not anti-metaphysical. The logical empiricists believed that the surface structure of sentences is not identical to their logical deep structure and that thus logical analysis is necessary to unravel the semantics of our messy language (e. g. [62, p. 170]). For example Quine, a champion of the old B-theory, subscribed – at least for a time – to the ‘empiricists’ anti-metaphysical program’ [30]. But people might think differently about the old B-theory. If the the old B-theory, is already a metaphysical view, as, one could argue, with the translatability of tensed into tenseless sentences comes the obligation to also give tenseless truth conditions, then Carnap may not even be compatible with the old B-theory. This however does not undermine my general point that Carnap’s views are not only in tension with the B-theory but that arguments for the A-theory can be built upon them. 18[73, p. xiii] for example speaks of ‘ “tensed” theories of time, in particular presentism’ which illustrates the entrenchment of this debate. 19 Nathan Oaklander states that ‘[t]ensed discourse is indeed necessary for timely action, but tensed facts are not’ [56, p. 58]. Oaklander’s claim does not amount to an argument for a tenseless theory, however. If ‘the truth conditions of tensed sentences can be expressed in a tenseless metalanguage that describes unchang- ing temporal relations between and among events’ [56, p. 58, my emphasis], this only makes a tenseless theory a viable option: without this ‘can’, a tenseless the- ory could not be held after Prior and Perry’s famous arguments. Consequently the NTT’ler want more and claim that tenseless facts are necessary as truth- makers for tensed sentences. We will not go into this here, but e. g. Mellor’s [50] arguments seem to only affect non-pure presentism [29]. If this is the case, then pure presentism might contest the necessity of the tenseless truthmakers. 20 I do not want to claim, that metaphysics is per se a bad thing. To say it with the words of Jiri Benovsky ‘What I aim at here is to provide myself and my reader with tools that enable us to evaluate the cost-benefit ratio of the different views under consideration’ [6, p. 8]. What may seem as a cost to one person may be seen as a virtue by another. Nevertheless it is important to make the implications of philosophical positions explicit. On top of that I take agnosticism to be a meta- theoretical value, i. e. I take a philosophical position that is less committing to be superior. It’s a variant of Occam’s razor: Do not subscribe to anything, which is not necessary. In this sense the NTT’s metaphysical commitment might ceteris paribus be seen as a cost. 21 As a consequence, Carnap concentrated on methods of justification ([26], [23] and [20]) and testability ([17] and [18]) rather than truth in the following. 22 Carnap’s complete account of measurement need not concern us here. I will highlight the bits, which are important for our present purpose in due course. The reader, who wants to know more about the three rules or other aspects of Carnap’s thoughts on measurement, is referred to Carnap’s An Introduction to the Philosophy of Science [11], which is easily accessible. 23[67, p. 78] Russell uses the term ‘name’ here, but what he refers to are indexicals. ‘This’ and ‘that’ are his prime examples. 24 Well, partly not surprising. On the one hand Carnap really believed that sen- tences with indexicals can and should be translated into their B-theoretic coun- terparts. On the other hand, as I will show, there are opposing tendencies in Carnap’s work, which can be used to base an argument in favour of the A-theory. Florian Fischer: Tensed Logic of Science 83

These two tendencies – towards the A- and towards the B-theory – are tempo- rally overlapping and can thus not be explained away trying to identify different phases in Carnap’s work. 25 The way I present the argument, it is confined to Carnap’s thoughts about mea- surement. Newer developments in measurement theory may change its systematic premises. I thank an anonymous referee for insisting on this point. This paper seeks to show the systematic impact of newer developments in the philosophy of time on the position that Carnap held, and a similar impact by the newer measurement theory is also plausible. I think that the transcendental argument is independent of this, but I can’t show this here. 26 Charlie Dunbar Broad [10, p. 58]), William Lane Craig [29, p. 118] and Thomas M¨uller[51, p. 206] also come to the conclusion that ‘now’ is (one of) the basic indexical(s). They state for example that ‘here’ is derivative of the indexicals ‘now’ and ‘I’, since ‘here’ actually means ‘where I’m now’. 27 The two ways of specifying the origin are also distinguished by Nicholas Rescher: ‘The distinction between dates and pseudo-dates points to the existence of two very different chronological dating-procedures, depending upon whether the fun- damental reference-point — the “origin” in mathematical terms — of the chrono- logical scheme is a chronologically stable date or a chronologically unstable pseudo-date. If the “origin” is a pseudo-date, say “today”, we shall have a style of dating all of whose chronological specifiers are pseudo-dates, e. g. tomorrow, day-before yesterday, four days ago, etc. If, on the other hand the “origin” is a genuine date, say the founding of Rome, or the accession of Alexander, we shall have a style of dating all of whose dates are of the type, e. g two hundred and fifty years ‘ab urbe condita’.’ [63, p. 79] 28 Truls Wyller [78][76][77][79] agrees that localisations like ‘X years before the birth of Christ’ are only apparently indicator-free [76, p. 74]. He is very explicit about the need for an indexical anchor: ‘The reference to the earthquake in San Francisco is only a help for temporal localisation if I know when the earthquake did take place. This knowledge can’t consist of further references to ‘objective’ circumstances. In order for me to know when a certain event took place, such reference-chains must have an indexical anchor somewhere. [. . . ] The same thing holds for conventional systems of dates, like the reference to the birth of Christ. This birth can only be used for temporal localisation, as such as it today marks a time point so and so many years ago.’ (Translation FF. [76, p. 74]. Albeit Wyller uses this in an argument for an different, more radical, conclusion: He argues for transcendental idealism. ‘In transcendental idealism, space and time are held to be nothing but forms of human experience. Accordingly, without the existence, somewhere in the universe, of human beings, there would be no space and time’ [77, p. 325]. 29 Truls Wyller agrees with this and may even go one step further, since he claims that empirical events are only locations if they are embedded into an indexical frame of reference: ‘Ihren Status als Lokalisationen gewinnen em- pirische Ereignisse allerdings erst durch ihre Eingliederung in ein indexikalisches Bezugssystem’ [76, p. 74]. 30 For the identification of B-time with time order, see [37] in this volume. 31[16, p.40] translation by FF. The German original is: ‘Wir kennen keinen An- fangspunkt der Zeitreihe. Es muß daher ein willk¨urlich gew¨ahlterZeitpunkt als 84 KRITERION – Journal of Philosophy, 2016, 30(2): 61–90

Nullpunkt der Zeitskala festgesetzt werden, wie es in den verschiedenen Kalen- dersystemen geschieht (Anfangsjahr; Anfangstag des Jahres).’ 32 The existence of tensed facts is not to be equated with presentism. According to presentism, the present is privileged in the strongest way possible, since ‘only currently existing objects are real’ [73, p. 11]. Kit Fine however argues that ‘it may be allowed that there are tensed facts (or the like) but denied that the present time is in any way privileged.’ [34, p. 262], i. e. that there are tensed facts without presentism. 33 I do not claim that all facts are tensed. Perhaps mathematical statements need tenseless facts as truthmakers. I just want to argue that not all tensed sentences can have tenseless truthmakers.

Florian Fischer University of Bonn Institut f¨urPhilosophie Am Hof 3 - 5 53113 Bonn

References

[1] Holger Andreas. Carnaps Wissenschaftslogik. Paderborn: Mentis, 2007. [2] A. J. Ayer. Logical Positivism. Free Press Paperback. New York: Free Press, 1966. [3] A. J. Ayer. The Foundations of Empirical Knowledge. London: Macmillan, 1940. [4] Yehoshua Bar-Hillel. “Indexical Expressions”. In: Mind 63.251 (1954), pp. 359–379. [5] Yehoshua Bar-Hillel. “Remarks on Carnap’s Logical Syntax of Lan- guage”. In: The Philosophy of Rudolf Carnap. Chicago, La Salle: Open Court, 1963, pp. 519–543. [6] Jiri Benovsky. “Four-Dimensionalism and Modal Perdurants”. In: Topics on General and Formal Ontology. Ed. by Paolo Valore. Poli- metrica International Scientific Publisher, 2006, p. 137. Florian Fischer: Tensed Logic of Science 85

[7] Laurence BonJour. “Epistemological Problems of Perception”. In: The Stanford Encyclopedia of Philosophy. Ed. by Edward N. Zalta. Spring 2016. 2016. [8] Thomas Bonk. Language, Truth and Knowledge. Contributions to the Philosophy of Rudolf Carnap. Dordrecht, Boston, London: Kluwer Academic Publishers, 2003. [9] David Braun. “Indexicals”. In: The Stanford Encyclopedia of Phi- losophy. Ed. by Edward N. Zalta. Spring 2015. 2015. [10] C. D. Broad. Scientific Thought. Abingdon-on-Thames: Routledge and Kegan Paul, 1923, pp. 406–411. [11] Rudolf Carnap. An Introduction to the Philosophy of Science. Mi- neola, New York: Dover Publications, 1995. [12] Rudolf Carnap. Der Logische Aufbau der Welt. Hamburg: Meiner Verlag, 1928. [13] Rudolf Carnap. “Der Raum: Ein Beitrag zur Wissenschaftslehre”. In: Kant-Studien 56 (1922). [14] Rudolf Carnap. “Intellectual Autobiography”. In: The Philosophy of Rudolf Carnap. Ed. by Paul Arthur Schilpp. Chicago, La Salle: Open Court, 1963. [15] Rudolf Carnap. Introduction to Semantics (Studies in Semantics, vol. I). Cambridge: Harvard University Press, 1942. [16] Rudolf Carnap. Physikalische Begriffsbildung. Wissen und Wirken. Karlsruhe: G. Braun, 1926. [17] Rudolf Carnap. “Testability and Meaning”. In: Philosophy of Sci- ence 3.4 (1936), pp. 419–471. [18] Rudolf Carnap. “Testability and Meaning (Part 2)”. In: Philosophy of Science 4.4 (1937), pp. 1–40. [19] Rudolf Carnap. “The Elimination of Metaphysics Through Logical Analysis of Language”. In: Logical Empiricism at Its Peak: Schlick, Carnap, and Neurath. Ed. by Sahotra Sarkar. Vol. 2. New York: Garland Publishing, 1996, pp. 10–31. [20] Rudolf Carnap. “The Logical Foundations of Probability”. In: Journal of Philosophy 60.13 (1963), pp. 362–364. [21] Rudolf Carnap. The Logical Structure of the World. Chicago, La Salle: Open Court, 1969. 86 KRITERION – Journal of Philosophy, 2016, 30(2): 61–90

[22] Rudolf Carnap. The Logical Syntax of Language. London: K. Paul, Trench, Trubner & Co., Ltd., 1937, pp. 303–304. [23] Rudolf Carnap. “Truth and Confirmation”. In: Readings in Philo- sophical Analysis. Ed. by Herbert Feigl and Wilfred Sellars. Des Moines: Appleton-Century-Crofts, 1949, pp. 119–127. [24] Rudolf Carnap. “Uber¨ die Abh¨angigkeit der Eigenschaften des Raumes von denen der Zeit”. In: Kant-Studien 30.1-2 (1925), pp. 331–345. [25] Rudolf Carnap. “Uber¨ Protokolls¨atze”.In: Erkenntnis 3.1 (1932), pp. 215–228. [26] Rudolf Carnap. “Wahrheit und Bew¨ahrung”. In: Actes du Congr`es International de Philosophie Scientifique (1936), pp. 18–23. [27] Rudolf Carnap and Martin Gardner. Philosophical Foundations of Physics. Vol. 966. New York: Basic Books, 1966. [28] David John Chalmers, David Manley, and Ryan Wasserman. Metametaphysics: New Essays on the Foundations of Ontology. Oxford: Oxford University Press, 2009. [29] William Lane Craig. The Tensed Theory of Time: A Critical Exam- ination. Dordrecht, Boston, London: Kluwer Academic Publishers, 2000. [30] Richard Creath. “Logical Empiricism”. In: The Stanford Encyclo- pedia of Philosophy. Ed. by Edward N. Zalta. Spring 2014. 2014. [31] Janet Farrell-Smith. “Russell on Indexicals and Scientific Knowl- edge”. In: Rereading Russell: Essays on Metaphysics and Episte- mology. Ed. by C. Savage and C. A. Anderson. Minneapolis: Uni- versity of Minnesota Press, 1989, pp. 119–137. [32] Uljana Feest. “Science and Experience / Science of Experience. Gestalt Psychologie and the Anti-Metaphysical Project of the Auf- bau”. In: Perspectives on Science 5 (2006), pp. 1–25. [33] J. N. Findlay. “Time: A Treatment of Some Puzzles”. In: Aus- tralasian Journal of Philosophy 19.3 (1941), pp. 216–235. [34] Kit Fine. “Tense and Reality”. In: Modality and Tense. Oxford: Oxford University Press, 2006. [35] Gottlob Frege. “Der Gedanke”. In: Logische Untersuchungen. Ed. by G¨unther Patzig. G¨ottingen: Vandenhoeck, 1918, pp. 30–53. [36] Gottlob Frege. “The Thought: A Logical Inquiry”. In: Mind 65.256 (1956). Ed. by Peter Geach, pp. 289–311. Florian Fischer: Tensed Logic of Science 87

[37] Cord Friebe. “Time Order, Time Direction, and the Presentist’s View on Spacetime”. In: Kriterion (2016). [38] Cord Friebe. Zeit – Wirklichkeit – Persistenz. Eine pr¨asentistische Deutung der Raumzeit. Paderborn: Mentis, 2012. [39] Akiko M. Frischhut. “What Experience Cannot Teach Us About Time”. In: Topoi (2013). [40] Antony Galton. The Logic of Aspect: An Axiomatic Approach. Ox- ford: Clarendon Press, 1984. [41] Aleksandar Jokic and Quentin Smith, eds. Time, Tense, and Ref- erence. A Bradford Book, 2003. [42] Jaegwon Kim and Ernest Sosa, eds. A Companion to Metaphysics. Blackwell Companions to Philosophy. Oxford, Cambridge, Mas- sachusetts: Blackwell, 1995. [43] Lothar Krauth. Die Philosophie Carnaps. Library of Exact Philos- ophy 1. Luxemburg: Springer, 1970. [44] Theo A. F. Kuipers. Handbook of the Philosophy of Science. Gen- eral Philosophy of Science – Focal Issues. Amsterdam: Elsevier, 2007. [45] James Ladyman. “Ontological, Epistemological and Methodologi- cal Positions”. In: General Philosophy of Science. Ed. by Theo A. F. Kuipers. North Holland, 2007, pp. 303–376. [46] Peter Ludlow. “Tense”. In: The Oxford Handbook of Philosophy of Language. Ed. by Ernest Lepore and Barry Smith. Oxford: Oxford University Press, 2006, pp. 689–715. [47] Barbara MacKinnon. American Philosophy: A Historical Anthol- ogy. Albany: State University of New York Press, 1985, pp. 219– 225. [48] Ulrich Majer. “Carnaps Ubernahme¨ der Gestalttheorie in den Auf- bau im Lichte heutiger, vor allem computationaler Theorien des Sehens”. In: Language, Truth and Knowledge: Contributions to the Philosophy of Rudolf Carnap. Ed. by Thomas Bonk. Alphen aan den Rijn: Kluwer Academic Publishers, 2003, pp. 65–73. [49] David Hugh Mellor. Real Time. Cambridge: Cambridge University Press, 1985. [50] David Hugh Mellor. Real Time II. London: Routledge, 1998. [51] Thomas M¨uller. Arthur Priors Zeitlogik: Eine problemorientierte Darstellung. Paderborn: Mentis, 2002. 88 KRITERION – Journal of Philosophy, 2016, 30(2): 61–90

[52] Thomas M¨uller, ed. Philosophie der Zeit: Neue analytische Ans¨atze. Klostermann, 2007. [53] Otto Neurath. “Protokolls¨atze”. In: Erkenntnis 3.1 (1932), pp. 204–214. [54] Otto Neurath. “Radikaler Physikalismus und wirkliche Welt”. In: Erkenntnis 4.1 (1934), pp. 346–362. [55] Ilkka Niiniluoto. “Carnap on Truth”. In: Language, Truth and Knowledge: Contributions to the Philosophy of Rudolf Carnap. Ed. by Thomas Bonk. Alphen aan den Rijn: Kluwer Academic Pub- lishers, 2003, pp. 65–73. [56] Nathan L. Oaklander and Quentin Smith, eds. The New Theory of Time. New Haven: Yale University Press, 1994. [57] Arthur Pap. “Reduction Sentences and Disposition Concepts”. In: The Philosophy of Rudolf Carnap. Ed. by Paul Arthur Schilpp. Chicago, La Salle: Open Court, 1963. [58] John Perry. “The Problem of the Essential Indexical”. In: Nous (1979), pp. 3–21. [59] Arthur N. Prior. “On the Unity of Professor Carnap”. In: Mind 73.290 (1964), pp. 268–269. [60] Arthur N. Prior. “Thank Goodness That’s Over”. In: Philosophy 20 (1959), p. 17. [61] Arthur N. Prior. Time and Modality. Santa Barbara: Greenwood Press, 1955. [62] Willard Van Orman Quine. Word & Object. The MIT Press, 1960. [63] Nicholas Rescher. “On the Logic of Chronological Propositions”. In: Mind 75.297 (1966), pp. 75–96. [64] Sebastian R¨odl. Kategorien des Zeitlichen: Eine Untersuchung der Formen des endlichen Verstandes. Frankfurt am Main: Suhrkamp, 2005. [65] Edmund Runggaldier. Carnap’s Early Conventionalism. Studien zur ¨osterreichischen Philosophie 7. Amsterdam: Rodopi, 1984. [66] Bertrand Russell. An Inquiry into Meaning and Truth. London: Allen & Unwin, 1950. [67] Bertrand Russell. Human Knowledge: Its Scope and its Limits. New York: Simon & Schuster, 1948. Florian Fischer: Tensed Logic of Science 89

[68] Sahotra Sarkar and Jessica Pfeifer. The Philosophy of Science: An Encyclopedia. London: Routledge, 2006. [69] Thomas Sattig. The Language and Reality of Time. Oxford: Clarendon Press, 2006. [70] Paul Arthur Schilpp. The Philosophy of Rudolf Carnap. Chicago, La Salle: Open Court, 1963. [71] Moritz Schlick. “Uber¨ das Fundament der Erkenntnis”. In: Erken- ntnis 4.1 (1934), pp. 79–99. [72] Carsten Seck. Theorien und Tatsachen: Eine Untersuchung zur wissenschaftstheoriegeschichtlichen Charakteristik der theoretis- chen Philosophie des fr¨uhenMoritz Schlick. Paderborn: Mentis, 2008. [73] Theodore Sider. Four Dimensionalism: An Ontology of Persistence and Time. Oxford: Oxford University Press, 2001. [74] Michael St¨oltznerand Thomas Uebel. Wiener Kreis: Texte zur wis- senschaftlichen Weltauffassung von Rudolf Carnap, Otto Neurath, Moritz Schlick, Philipp Frank, Hans Hahn, Karl Menger, Edgar Zilsel und Gustav Bergmann. Vol. 577. Hamburg: Meiner Verlag, 2009. [75] Thomas Uebel. Empiricism at the Crossroads: The Vienna Circle’s Protocol-Sentece Debate. Chicago, La Salle: Open Court, 2007. [76] Truls Wyller. “Die Alternativ- und Perspektivlosigkeit der in- dexikalischen Zeit”. In: Philosophie der Zeit: Neue analytische Ans¨atze. Ed. by Thomas M¨uller.Frankfurt am Main: Klostermann, 2007. [77] Truls Wyller. “How Big? How Fast? Transcendental Reflections on Space, Time and World Models”. In: Philosophy 84.3 (2009), pp. 325–339. [78] Truls Wyller. “Indexikalit¨at und empirische Objektivit¨at”. In: Zeitschrift f¨urphilosophische Forschung 49.4 (1995), pp. 553–570. [79] Truls Wyller. The Size of Things: An Essay on Space and Time. Paderborn: Mentis, 2010.

Time Order, Time Direction, and the Presentist’s View on Spacetime

Cord Friebe

Abstract The physical possibility of spacetimes containing closed timelike curves (CTCs) challenges the philosophy of time in the way that temporal ordering is, at best, remarkably non-standard: events on CTCs precede themselves. Apparently, such universes do not possess a consistent time order but only a consistent time direction. Thus, temporal directionality seems to be more fundamental than ordering in earlier-later or past-present-future. I will argue that this favors presentism as the adequate ontology of spacetimes: only presentism consistently copes with the idea that temporal ordering depends on empirical constraints. The presentist Now is fundamentally undivided and productively directed towards existence. Time order arises by extending the Now, which can fail and in fact fails in universes containing CTCs.

Keywords: general relativity, philosophy of time, presentism

1 Introduction

In 1949, Kurt G¨odelfamously presented a solution of Einstein’s generally relativistic field equations that permits the occurrence of closed timelike curves (CTCs).1 According to G¨odelhimself, the possibility of CTCs confirms ‘the’ idealist philosophy of time, namely what he takes to be the view that time is unreal, i.e., that the objective world is timeless: [I]t seems that one obtains an unequivocal proof for the view of those philosophers who, like Parmenides, Kant, and the modern idealists, deny the objectivity of change and consider change as an illusion or an appearance due to our special mode of perception. ([6], 202)

Kriterion – Journal of Philosophy, 2016, 30(2): 91–106. http://www.kriterion-journal-of-philosophy.org c 2016 The author 92 KRITERION – Journal of Philosophy, 2016, 30(2): 91–106

Consequently, the inference drawn above as to the non-ob- jectivity of change doubtless applies at least in these worlds [containing CTCs] [...] strengthening further the idealistic viewpoint. ([6], 205)

[N]o reason can [hence] be given why an objective lapse of time should be assumed at all. ([6], 206)

Nowadays, philosophers of physics disagree. They hold that even space- times containing CTCs have a temporal dimension (see, e.g., [4]; [5]; [9]). Thus, they are realists about time, at least as long as spacetime is ‘time orientable’. I agree that the occurrence of CTCs does not contradict the objectivity of time. It is unclear, however, in which sense time is ‘objective’ or ‘real’, and, correspondingly, in which sense CTC-spacetimes have a ‘temporal dimension’. The analytic philosophy of time offers, roughly, two different views about what real time consists in: either it is “B-time” or “A-time”, i.e., either it is essentially the ordering of earlier-later or the directionality of a moving Now. I will argue that the possibility of CTCs is in conflict with B-time-order but requires A-time-direction. Then, the question arises of whether spacetime grounds A-time or rather the other way around: that presentness grounds spacetime, containing CTCs or not. I will suggest this latter option: universes containing CTCs motivate to develop a reasonable theory of presentism. The plan is as follows: In Section 2, I will briefly recap both the essentials of general relativity and of the analytic philosophy of time. Upon these physical and metaphysical basics, Section 3 provides the argument in favor of time directionality being more fundamental than ordering. Finally, Section 4 argues that presentness is more fundamental than spacetime.

2 Physical and Philosophical Basics

The paper aims to demonstrate the relevance of the A- vs. B-time dis- tinction for the ontology of relativistic spacetimes. This section presents the basic elements of general relativity and central themes from the cur- rent philosophy of time, as they are relevant for my purpose. Cord Friebe: Presentist’s View on Spacetime 93

2.1 General Relativity To begin with, take a 4-dimensional (differentiable) manifold to rep- resent spacetime. Every physically possible spacetime has a lightcone structure, i.e, with every spacetime point p is associated a lightcone such that the distinction between timelike, lightlike, and spacelike vectors is ‘everywhere’, at every p, available. In particular, a timelike vector points inside the lightcone and is conventionally called “future-directed” iff it points into the upper lobe (and “past-directed” otherwise, i.e., iff it points downwards). Then, spacetimes are time orientable iff a con- tinuous designation of “future-directed” and “past-directed” for timelike vectors can be made over the entire manifold.2

Figure 1: Time orientability: any continuous transport of a timelike vector must preserve its orientation.

It should be emphasized that any simply connected spacetime is time orientable, a spacetime that is not time orientable is hence topologi- cally strange. Consider, in particular, a timelike curve: a curve is called “timelike” iff its tangent vectors are ‘always’, at every point of the curve, timelike. Such a curve lies inside all of its lightcones. Given time ori- entability, one may say that such a curve is ‘always’ future(or, past)- directed, and only given this, monotonically increasing parameters may consistently run along timelike curves – the (even invariant) proper times along worldlines. Therefore, time orientability is generally taken to be a necessary condition for time to be real. 94 KRITERION – Journal of Philosophy, 2016, 30(2): 91–106

Figure 2: Proper time τ consistently parametrize every timelike curve ω.

However, it is questionable whether time orientability is also sufficient for spacetime to have a temporal dimension. For it does not exclude the possibility that a timelike, even ‘always’ future-directed, curve can be closed (or, almost closed). Intuitively, in such a case, the event located at a given starting point p precedes itself. G¨odel’schallenge precisely was that even Einstein’s field equations allow for such a possibility so that it is not only mathematically compatible with time orientability but also physically possible. He concluded that the objective world is timeless. Still, it is undoubtedly not the case that the events on a CTC are simultaneous. Rather, the distinction between events being simultaneous and being non-simultaneous – a distinction which seems to be crucially temporal – is still available. Given this, one has good reason to sustain that universes containing CTCs are temporal. To sharpen the problem, it is instructive to confront an event/observer on a CTC with a freely falling body along a geodesic (see Figure 3): the hypothetical observer on the CTC is not simultane- ous with any event on the CTC but, e.g., with the body/event located at p0. However, (s)he is located at p ‘more than once’, namely modulo (periodic) τω. Does that mean – and what exactly could that mean – that the observer is ‘again and again’ simultaneous with the body/event Cord Friebe: Presentist’s View on Spacetime 95 at p0? I will argue that the B-theorists of time, focusing on the (partial- )order of earlier-simultaneous-later, are in trouble here and, so, that the possibility of CTCs favors tensed (A-) theories of time.

Figure 3: Is the observer at p again and again, at periodic τCTC , simul- taneous with the event at p0?

2.2 Analytic Metaphysics of Time Before arguing in favor of tensism, let me rewrite carefully the A- vs. B-time distinction from the analytic philosophy of time. One might have the impression that, according to the B-theorists, the world is a rather static block universe, whereas, according to the A-theorists, the objective world is really dynamical – ‘growing’, or whatever – in virtue of an ontologically distinguished present. So, seemingly, a B-theory is much closer to allegedly static CTC-universes than the A-theories. However, this impression is misleading. For, on the one side, self-declared B-theorists, such as Mellor ([8]), defend “real” time and “real” change and so apparently do not intend 96 KRITERION – Journal of Philosophy, 2016, 30(2): 91–106 to be closest to static block universes. And, on the other side, there is a very prominent A-theory – namely, the so-called moving-spotlight view – which in fact assumes an existentially static block universe: the moving Now is rather an irreducible property than an existentially distinguished event. Therefore, the distinction between A- and B-theories of time is fairly independent from the (alleged) dynamics of existence.3 It is rather about ordering and directionality. According to the B-theorists, real time consists in the relation of earlier-later. Events (et al.) are temporal in the B-theorist’s sense, i.e., they are in B-time iff they are earlier and/or later than some other events, perhaps also simultaneous with some other events, respectively. B-time is hence fundamentally time order. B-time direction, by contrast, is a derivative concept: nothing more than the convention or a physical fact of whether p is earlier than p0 or vice versa. According to the A-theorists, real time is grounded in the present. The meaning of “A-time” depends on that single point rather than on an infinite set of points to be ordered.4 Its motion is (somehow) directed, and A-time is hence fundamentally time direction. Time order emerges derivatively, in virtue of the directed motion of the present. Accordingly, the moving-spotlight view (usually) presupposes the existence of a so- called C-series of events – a non-temporal ordering of events. The present is in relative motion against this C-series and turns it into a (temporal) B-series. However, there is a tendency in the philosophy of physics to downplay the provided sharp contrast between A- and B-theories of time. One prominent example is the metaphysics of time, found by Maudlin ([7], chap. 4) within physics. Maudlin argues for a block universe that – ‘nevertheless’ – contains the “passage of time”. NB, he does not defend a version of the moving-spotlight view but somehow undermines the traditional classification of theories of time. “Temporal passage” is taken to be primitive, unanalyzable. In particular, one cannot analyze whether such a passage consists in directionality or in ordering. Let me sketch why the analytic distinction still matters. Apparently, the notion of passage is used by Maudlin only in its general sense. It needs to be specified, A- and B-theorists would reply. In one specifi- cation of the term, it means a (continuous) succession of numerically different points (or, events). In this line, “passage” is expressible by an ordering relation such that time differs from timeless manifolds (such as space) in the way that moments of time are ordered by the earlier- later relation as opposed to other, timeless, relations. According to this Cord Friebe: Presentist’s View on Spacetime 97 view, time is essentially time order which view one can call “B-theory”. In the other specification, by contrast, “passage” means a (continuous) motion of one single point, the present. According to this view, time differs from timeless entities (such as space) not (primarily) in virtue of a special ordering relation but due to a characteristic directedness of the moving Now. Understood in this way, time is essentially time direction which view one can call “A-theory”. These are exclusive specifications of “passage”: no synthesis is available, let alone by taking it primitively. Finally, there is a further, important variant of the tensed (A-) theo- ries of time which is most relevant for my purpose: presentism. Accord- ing to this view, the present is in fact existentially distinguished: only present entities exist. Time fundamentally consists in the present so that, more strikingly as before, time cannot consist in temporal ordering but only in its directionality. The presentist A-theorist would argue that passage is a productive ‘succession’, a continuously coming into being of the present. In contrast to directions in space, “time direction” has, then, an existentially productive sense.

3 What is Fundamental: Time Order or Time Direction?

On a CTC, every event is timelike separated from itself, it “chronolog- ically precedes itself” ([4], 259). Here, “chronological” can firstly be taken in its purely technical sense, i.e., there is a non-zero (negative, or timelike) spatiotemporal distance between p and p itself when measured along the closed curve. The interpretative question is whether events on a CTC temporally precede themselves. The first sense is at best purely physical (perhaps, merely geometrical), whereas the second is metaphys- ical. One might be inclined to the view that the former implies the latter, but one also might be skeptic: for, all events on a CTC are equivalent – namely ordered by a reflexive, symmetric, and transitive relation –, so they are, apparently, temporally on a par. On the other hand, events on a CTC are not simultaneous: as said, figure3 shows that the event at p is simultaneous rather with the one at p0 than with some other event on its CTC.5 Thus, the equivalence does not mean that the events on a CTC are simultaneous and so not that they are temporally on a par in that (usual) sense. Again on another hand, no event on a CTC occurs before or after another such event, and a fortiori no event occurs before or after itself. Being non-simultaneous does not imply occurring before- or afterwards. According to Dorato, different events on a CTC are related by a (very) peculiar relation of “temporal 98 KRITERION – Journal of Philosophy, 2016, 30(2): 91–106 betweenness” ([4], 262). So, perhaps, the event at p is indeed temporally separated from itself, not because it is earlier or later than itself but because other events are located temporally in between: between p and p itself. Following Dorato, the lesson from CTCs is that time order is some- how different from what the traditional B-theorists of time have in mind. Analytic metaphysicians may believe that it is an a priori truth that temporal order is earlier-later, namely an irreflexive, asymmetric, and transitive relation. Scientific metaphysicians, by contrast, believe, in a Quinean fashion, that meaning always has an empirical aspect: what a time order is, (partly) depends on scientific theories. In the case at hand: “time order” means something such that even CTCs can represent a pe- culiar temporal order. That’s precisely how anti-armchair-philosophy works! However, other scientifically minded philosophers (rightly) disagree: CTCs exist only for spacetimes that possess a globally consis- tent time direction but not a globally consistent time order. ([5], 94) Although a CTC is everywhere timelike – and, hence, every event on a CTC “chronologically” precedes itself –, one cannot consistently say that an event temporally precedes itself. The notion of temporal, they suggest, has – at least partly – a philosophical meaning that goes be- yond the purely technical concepts of general relativity. The possibility of CTCs allegedly is in contradiction with any reasonable meaning of temporal order. Consequently, such spacetimes do not have a “globally consistent” time order, and that means that they do not have a time order at all. At this point, one might object that according to Earman et al. such spacetimes indeed have locally consistent time order(s), within small neighborhoods around every point. However, this is so only for prag- matic motives, analogous to the spatial geometry of a sphere which pragmatically allows the speech of right and left in small neighborhoods around the points. In this case, one would say, I guess, that only for practical reasons it is convenient to talk about right and left, locally. Globally, however, and so objectively, there is no consistent right-left or- der but spherical coordinates (angels) are the metaphysically adequate ones. Likewise, in universes containing CTCs it might be reasonable for practical purposes to talk of earlier and later, locally. Globally, and so objectively there is no earlier-later order on a CTC but a symmetric and reflexive order only. Cord Friebe: Presentist’s View on Spacetime 99

‘Nevertheless’, spacetimes containing CTCs allegedly have a tem- poral dimension also according to Earman, Smeenk and W¨uthrich. In contrast to G¨odel,they do not conclude that general relativity denies the reality of time, namely because they do not conclude that universes with- out time-order are timeless. The reason for that is neither geometrical or physical, nor Quinean: Earman et al. neither recall some geometrical or physical facts (such as lightcone structure) that also G¨odelwas aware of, nor argue that “time order” gets a different meaning in modern physics. Instead, they introduce a further philosophical notion to interpret the geometrical/physical situation, namely “time direction”. Universes with CTCs have a temporal dimension exactly because they possess a glob- ally consistent time direction, they argue. Hence, here “time” does not mean time order but time direction. This is a remarkable claim because, consequently, the meaning of time direction should not depend on the meaning of time order: “temporal” essentially means time directionality – time direction is more fundamental than time order. B-theoretically, however, time direction depends on (traditional) time order.6 Given the irreflexive, asymmetric, and transitive relation < of earlier-later, time direction is derived when it is consistently possible to assign whether p < p0 or p0 < p. This might be a mere convention or is grounded in physical facts such as the past hypothesis:7 in any case, B-time is directed iff an arrow consistently points from (fundamen- tal) earlier to later. I don’t see how this concept can be applied with “temporal betweenness” alone, as Dorato must have it. In that case, the challenge for the B-theorists would be: How can mere temporal be- tweenness (without before- and afterwardness) ground time direction? From ‘where’ to ‘where’ points the arrow? As it seems to me, the time directionality from Earman et al. is rather independent from Dorato’s non-traditional time order, so at least equally fundamental anyway. Taking time direction as a (or, even the) fundamental concept, as Earman et al. in fact do, apparently requires tensed time (A-time). A- theoretically, the meaning of temporal depends on the objectively ‘mov- ing’ present. Its motion is directed so that A-time essentially consists in that time directionality. According to the moving-spotlight variant, the transitory present is not existentially distinguished but by being an intrinsic and changing (‘moving’) property of presentness – metaphor- ically represented by a spotlight. This spotlight is in relative motion against an existing series of objects or events, traditionally understood as ordered by an irreflexive, asymmetric, and transitive relation (Mc- Taggart’s timeless C-series). In that case, the timeless series turns into 100 KRITERION – Journal of Philosophy, 2016, 30(2): 91–106 a temporal B-series, in virtue of the transitory present. It is its directed motion that gives the relation < the sense of earlier-later. Time direc- tionality – which is given by the single point of presentness – grounds time order (of a set of points), and not the other way around. In the case at hand, however, there is not even a C-series of events: on a CTC the points are ordered by an equivalence relation. Thus, along a CTC the moving spotlight cannot (and should not) produce a temporal B- series. One has its directionality without time order, in accordance with the claim that there is a globally consistent time direction but no time order. However, the problem with this view is that it requires su- per(space)time dimension(s) in order to give room for the peculiar change of the Now. It threatens to be McTaggart-contradictory, i.e., each event threatens to be equally past, present, and future, unless one introduces an infinite, perhaps even vicious, regress of meta-dimensions. Despite of this argument, Skow ([9]) provides a moving-spotlight interpretation of relativistic spacetimes.8 Personally, I do not see how Skow super- sedes McTaggart’s worries and, consequently, will not provide a further argument against the moving-spotlight variant. Instead, I will focus on an important difference between moving-spotlight and presentism: both A-theoretic options take time directionality as the fundamental essence of real time, but the first take spacetime as more fundamental than time whereas the latter must take time as more fundamental than spacetime. The moving-spotlight A-theory of time presupposes the existence of the whole of spacetime upon which and against which one (or, many inde- pendent) Now-points can perform its (their) motion(s). According to presentism, no thing eternally exists, a fortiori no spacetime as a four- dimensional block, but only the present. So, the presentist’s ‘moving’ Now underlies spacetime rather than the other way around.

4 Fundamental Time Direction: the Presentist’s View

In my view, the only consistent philosophy of time that copes with the idea that time direction is more fundamental than time order is pre- sentism. So, if the lack of a (globally consistent) time order does not imply the timelessness of those spacetimes (containing CTCs), and if its temporality is essentially directionality – as it is claimed by Ear- man/Smeenk/W¨uthrich –, one should take it as an indicator for the view that the metaphysics of time is presentism. Then, spacetime is ontologically derivative, existentially grounded in a ‘moving’ Now which Cord Friebe: Presentist’s View on Spacetime 101 underlies spacetime (containing CTCs or not). In order to spell out a bit the essential idea of presentism, look, for contrast, again at the moving spotlight: its motion is relative, namely against an ‘already’ existing series of spacetime points or events located there. Accordingly, the presentist Now must be in some radical non- relative motion, so in an absolute motion neither against ‘already’ ex- isting bodies/events nor against ‘already’ existing space or spacetime. Although against nothing, it still must be ‘in motion’, otherwise the transitory aspect of time is lost. The presentist Now is not an isolated moment of B-time which would be indistinguishable from an isolated spatial (timeless) point. An isolated moment of B-time would be struc- tureless, while something happens with (or, rather, within) the presentist Now. The logical question is whether this happening is intelligible, and the metaphysical question is if it is compatible with relativity, in partic- ular, with universes containing CTCs. The presentist Now is not only no isolated moment of B-time but not a moment of time at all: it is simply time. There is (on the fundamen- tal) level neither the relational structure of earlier-later nor that of past- present-future: A-time is fundamentally undivided. This has a twofold advantage: logically, a McTaggart-contradiction cannot arise simply be- cause there is no past nor future; physically, presentism is prima facie compatible with CTC-universes since those universes are not divided into earlier and later but ‘nevertheless’ have a temporal dimension. Although being undivided, the presentist Now cannot be structureless: for, as said, it must be distinguishable from a timeless point. As I would suggest, its structure consists in the distinction between coming into being and annihilation. The crucial difference to a static point (and to a point in relative motion) is that the presentist Now does not persist. It rather comes into existence to vanish immediately. So, its peculiar internal motion consist in the productive activity of continuously coming into existence and going out of existence. These two aspects, however, are related to each other asymmetrically: it firstly comes into existence and secondly goes out of existence, not the other way around, and so on and so on. Therefore, time (i.e., the present) is essentially directed, namely towards existence, and therefore directionality is the fundamental essence of time. In order to create spacetime, the presentist Now has to be extended. This has firstly a spatial sense: the point (in its internal motion) has to be extended to create space, i.e., a simultaneity slice of, say, three dimensions. At this point, the challenge from special relativity enters: 102 KRITERION – Journal of Philosophy, 2016, 30(2): 91–106 it forbids an absolute (meaning here: frame-independent) foliation of spacetime so that the continuously produced simultaneity slices must not be invariant. As argued elsewhere, presentism can but can only made compatible with special relativity if the (objective) extending of the Now-point is observer-dependent.9 There is secondly a temporal sense of extending the Now-point:10 presentist time, which is fundamentally not directed upwards or down- wards in spacetime but points productively into the peculiar, singular direction of existence, must be extended in a second sense to create the temporal relation of past-present-future or earlier-later. Extending the presentist Now in the temporal sense (objectively) produces new struc- ture, i.e., renders time dividing into past and future. Also this must be observer-dependent, already to make presentism compatible with spe- cial relativity. At this point enters the challenge from general relativity: derivative time, i.e. time-order, further depends on empirical conditions. In the case of G¨odelianuniverses, there are empirical conditions that strike against the division of time so that no time order arises. Under these circumstances, it is physically impossible to objectively extend the presentist Now in the temporal sense. Here, presentist time (presentness, the Now) remains undivided (“no order”), purely directed. Therefore, there is only a globally consistent time direction but no time order in spacetimes containing CTCs.

5 Conclusion

The paper intends to provide a scientifically minded motivation for a presentist reading of spacetime theories, a stimulant for developing a theory of relativistic presentism. The physical possibility of spacetimes containing CTCs leads to the following reasoning: if one is after a metaphysically-temporal interpretation of all (time-orientable) space- times, the meaning of temporal essentially consists in directionality. Only presentism consistently copes with the idea that time direction is more fundamental than time order. Spacetime, then, is ontologically derivative, dependent on a fundamental Now which essentially points to- wards existence. Its essence is an existentially productive directionality. The theories of relativity offer empirical constraints under which the fundamental presentist Now can be objectively extended, both in a spa- tial as well as in a temporal sense. In its temporal sense, (observer- dependent) extending the Now leads to the temporal division into past- present-future or earlier-later. Under certain empirical circumstances, Cord Friebe: Presentist’s View on Spacetime 103 realized in the G¨odeliancases, the temporal extending of the Now ob- jectively fails so that no objective time order arises. Only time direction- ality is real in such worlds. Since those worlds are physically possible, time directionality also is fundamental in the actual world. (This mimics G¨odel’sown reasoning, according to which the actual world is timeless since CTC-universes are physically possible.)

Notes

1 To be more precise, in G¨odel’suniverse a CTC goes through every spacetime point, but nothing hangs on this: the challenge for the philosophy of time consists in the mere occurrence of CTCs through some spacetime points (which is, by the way, the more realistic possibility). 2 The precise definition of time-orientability (including lightlike vectors) doesn’t matter here. 3 Indeed, the existentially dynamic growing block universe is B-theoretic in the sense that “presentness” is reduced to ‘nothing exists that is later than’ (see [3], 69f.). 4 Perhaps, there is more than one single present, but, also then, time surely does not consist in the ordering of these points. 5 For more on “simultaneity” and (corresponding) measurements in curved space- times see [2] (chap. 4 and 6). 6 Note that the usual way in which the ‘arrow’ of time has been debated in the philosophy of physics is based on temporal order. Usually, one presupposes the view of a tenseless block universe and asks whether such a universe physically allows a specific time orientation. With universes containing CTCs in mind, one should change the perspective and ask the following question: given a temporal direction, what are the physical constraints to get also a temporal order? 7 According to the past hypothesis, the early universe was in a low entropy state, which apparently saves the time asymmetry of the second law of thermodynamics; see, e.g., [1]. 8 Note that, in the CTC-case, superspacetime is likewise G¨odelianso that the directed motion of the spotlight in fact does not produce a temporal B-series. 9 The observer-dependence of space must, hence, not be in contradiction with objectivity. How this might work, has been shown on other occasions, e.g., in Anonymous. 10 The following sounds similar to Bergson’s mind-dependency of the B-theoretic earlier-later relation (see Anonymous2, this volume).

Acknowledgements

I would like to thank the audience of the Philosophy of Time Symposium, held at SOPhiA 2014 (Salzburg), and two anonymous referees of this 104 KRITERION – Journal of Philosophy, 2016, 30(2): 91–106 journal for helpful comments on earlier versions of the paper. Special thanks go to the SPoT Discussion Group at Bonn. Financial support stems from the Deutsche Forschungsgemeinschaft, project FR 1461/6-1.

Cord Friebe University of Bonn, Germany Institute for Philosophy Am Hof 1 D-53113 Bonn

References

[1] Albert, D.Z. (2000). Time and Chance. Cambridge (MA): Harvard University Press

[2] Clarke, C.J.S. and F. de Felice (1992). Relativity on Curved Man- ifolds. Cambridge: Cambridge University Press.

[3] Dainton, B. (2001). Time and Space. Chesham: Acumen Publish- ing.

[4] Dorato, M. (2002). On becoming, cosmic time and rotating uni- verses. In: Callender, C. (Ed.). Time, Reality, and Experience. Cambridge: Cambridge University Press, 253–276.

[5] Earman, J., C. Smeenk, and C. W¨uthrich (2009). Do the laws of physics forbid the operation of time machines? Synthese 169 (1), 91–124.

[6] G¨odel,K. (1949). A remark about the relationship between relativ- ity theory and idealistic philosophy. In: G¨odel, K. [1990]. Collected Works Vol II. New York/Oxford: Oxford University Press, 202– 207.

[7] Maudlin, T. (2007). The Metaphysics within Physics. Oxford/New York: Oxford University Press. Cord Friebe: Presentist’s View on Spacetime 105

[8] Mellor, D.H. (1998). Real Time II. London: Routledge. [9] Skow, B. (2009). Relativity and the moving spotlight. The Journal of Philosophy Vol. CVI, No. 12, 666–678.

The Mind-Dependence of the Relational Structure of Time (or: What Henri Bergson Would Say to B-theorists)

Sonja Deppe

Abstract Tenseless theorists assert that the relational structure of earlier/ later is the essential structure of time. Using B-notions, so they think, we speak about time ‘as it is’ in a metaphysical sense and hence from the outside of our subjective perspective on it. I suggest on the contrary that the relational structure of earlier/later is part of our own intellectual structuring within the access to temporal phenomena. Furthermore it is essentially characterized by the structure of juxtaposition which originates in spatial experience rather than in temporal. In order to show this I consult Henri Bergson’s analysis of our temporal experience on the one hand and of our intellectual practice on the other hand. I will conclude that it is not unplausible to take the relational account of time to be more closely connected to the nature of our intellect than to the nature of time itself.

Keywords: Philosophy of Time, B-Theorie, Henri Bergson, mind-dependence

1 Introduction

The debate between tensed and tenseless theories of time, i. e., between A- and B-theorists traces back to J. Ellis McTaggart’s seminal paper The unreality of time [12]. Unlike McTaggart, however, neither of the opposed theories contests the fact that time is real, hence that reality is structured in a temporal way (cf. [10, p. 9]). The metaphysical dissent between A- and B-theorists concerns rather the question of what is ‘essential to the nature of time’ [12, p. 458]. The core of the debate, I would say, is to identify the essential, i. e., fundamental structure of time; and in doing so, to expose an essential structural aspect of reality.

Kriterion – Journal of Philosophy, 2016, 30(2): 107–124. http://www.kriterion-journal-of-philosophy.org c 2016 The author 108 KRITERION – Journal of Philosophy, 2016, 30(2): 107–124

On the one hand, advocates of a tensed theory of time or A-theorists believe that time is essentially structured in a way that can be referred to by so called A-notions as ‘past’, ‘present’, and ‘future’ (cf. [7, p. 3]). Those notions refer to the concept of ‘now’ that A-theorists take to be metaphysically important. For them, referring to the present and to its constantly varying contents is indispensable for grasping the essential structure of time. Tenseless theorists or B-theorists, on the other hand, claim that A- notions are not necessary to characterize time in metaphysical respects. What is real about time, so they tell us, is that events are related among each other in a way that can be described by so called B-notions such as ‘earlier than’, ‘later than’, and ‘simultaneous with’ (cf. [13, p. 15]). Thus, for them, time is essentially structured in a relational way. Actu- ally B-theorists wouldn’t necessarily deny that A-notions can be useful to describe our experience of temporal phenomena. They contest, how- ever, that some objective feature is referred to by this way of speaking (cf. [13, p. 42 et sqq.]). As Heather Dyke puts it:

According to this [tenseless] view the distinction between past, present and future is not a characteristic of time itself, but merely a distinction that we project onto time, from our perspective. [8, p. 332]

The A-structure1 is hence understood as a structuring that merely re- flects the subject’s access to and particular perspective upon temporal reality. In this respect, B-theorists treat ‘now’ in a similar way like ‘here’, which usually is not taken to refer to the structure of space itself but to our own perspective-depending structuring of space in relation to ourselves. In this sense, B-theorists sometimes claim properties referred to by A-notions to be merely mind-dependent (cf. [1]). Usually the core of the dispute between tensed and tenseless theorists seems to be the metaphysical status of the A-structure,2 although the initial question appears to be a symmetrical one: Both of the opposing parties try to prove that one structure of time - the one that they favour - is the essential one in the metaphysical respect and try to find reasons for taking the other structure to be derivative. However, the A-structure and its metaphysical relevance is usually the core issue discussed between tensed and tenseless theorists, presumably because of the following rea- sons. Firstly, since McTaggart we have to face the question whether the A-structure is self-contradictory (cf. [11, p. 24 et seqq.]). Secondly, (based on the first point or independently of it) there is an argument Sonja Deppe: Mind-Dependence of the Relational Structure of Time 109 whether referring to ‘now’ is necessary (and/or possible, and/or plausi- ble) in order to characterize time in a metaphysical respect. Crucial to this discussion is the aforementioned question of whether A-notions are objectively relevant (cf. [8, p. 332 et seqq.]). Observing the debate, one could gain the following impression at first glance: If the tenseless view of A-notions being merely mind-dependent turned out to be right, B-theorists would be entitled to triumph because the relational structure of B-notions would remain alone to be the essen- tial feature of time in the metaphysical respect. This reasoning, however, in my opinion is premature for it omits to return the question to the B- theorists, i.e. to examine critically if, from a metaphysical point of view, the B-structure itself can convincingly be thought as the essential feature of time. What is disregarded here is the possibility that the B-structure might have problems on its own.

2 Challenging the mind-independence of the B-structure

In this article I will attempt to provide a reverse approach: I will aim directly at the relational B-structure and challenge the plausibility of its role as a mind-independent feature of the essential characterization of time. My question is: Is it really convincing, as often implied, to think of the relational B-structure of time as being inherent in time itself, independently from our grasping of it? The question whether a certain feature is something we encounter in the external world or whether it only belongs to ourselves, structuring our own access to the external world, is obviously a decisively metaphys- ical question. What are our instruments for tackling it? In metaphysics, as I understand it, we are establishing models of reality (or just single theses about it) and inquire into their consistency on the one hand and their accordance with our experience on the other hand. The results of both will render a particular model (or thesis) more or less plausible. In this paper I am going to claim that a view that takes the tempo- ral B-structure to be mind-dependent is by no means unplausible. More precisely I will motivate its plausibility from two directions: Firstly I will indicate that there is an access to time - in fact a very basic one, namely our original experience of temporal phenomena - where the B-structure is not encountered. Rather quite contrary structures seem to dominate here. This result may surprise at first glance since within our every- day handling of time obviously the structure of earlier/later does play a quite effective role. Hence, in order to give my thesis consistency and 110 KRITERION – Journal of Philosophy, 2016, 30(2): 107–124 plausibility I have to explain why the structure in this context may be considered as secondary and thus is not metaphysically relevant. That’s why my second argument will tackle the possible mind-dependence from the issue of the mind: I will consider typical structuring processes that human subjects use when accessing reality. I will then claim that our mind has the tendency to impose a certain kind of structure for the purpose of simplification in the context of acting and that the temporal B-structure may very well be of this type. For both arguments I will bring into play the perspective of the French philosopher Henri Bergson whose detailed reflections about time also focus on the subject of the structure of time, even though they are quite different from the debate between A- and B-theorists.3 In contrast to those theorists, he does not start directly within the field of metaphysics, but prepares the metaphysical reasoning by thoroughly analysing our temporal experience first. More precisely, he tries to reveal the essence of temporal experience by exposing its specific structure and by contrasting it with the structure of spatial experience. Having carved out those different structures he contends that, in some contexts, we have a tendency to favour spatial structures with respect to temporal structures for practical reasons. He points out that ordering contents within spatial structures is part of our intellectual practice. Bergson’s reasoning may lead us to reflect in more detail on the con- nection of temporal structures, spatial structures and intellectual prac- tice. This consideration may challenge an overhasty ascription of certain structures to mind-independent reality (in particular spatial structures within the context of time) and in this sense have an impact on our metaphysical reasoning. Hence, following Bergson, I will leave the area of metaphysics be- hind for a while, in order to present his analysis of human experience in its spatial and temporal form. Subsequently we will see his analysis of intellectual structuring mechanisms of human mind in more detail. Afterwards I will turn back to the issue of metaphysical reflection.

3 Henri Bergson: Spatial and temporal experience

Referring to Kant, Bergson exposes two forms of intuition that underlie human experience. As I will now explain in more detail, he takes the spatial and the temporal way of grasping contents of experience to be contrary in many aspects: Analysing our spatial approach to experienced contents, Bergson Sonja Deppe: Mind-Dependence of the Relational Structure of Time 111 carves out a structural pattern that can be summed up by the key word juxtaposition. Juxtaposition allows us to consider several things together but separately (cf. [5, p. 75-99], [3, p. 56-74]). This structure of jux- taposition suggests itself when it comes to our concrete experience of perceptual space, e. g. in our visual perception of extended objects within space. Bergson illustrates this by our perception and/or repre- sentation of a flock of sheep: Let us assume that all the sheep in the flock are [quali- tatively] identical; they differ at least by the position which they occupy in space, otherwise they would not form a flock. [5, p. 77] (cf. [3, p. 57]) The spatial structure allows us both to perceive several objects at once and at the same time to discriminate them referring to their differing position in space. The mathematical understanding of space sharpens this structure of juxtaposition which is at the same time accumulating and differentiating within the conception of a set of equal and discrete positions. I will have to say a little bit more about the structure of juxtaposition later. But first, let’s see what Bergson tells us about temporal structure (cf. [5, p. 85-128], [3, p. 63-96]). Again, Bergson takes his start from our experience. What kind of structure can we discover within our orig- inal experience of temporal phenomena? For Bergson it is most obvious that this structure is definitely not the same as in the spatial context, i.e. juxtaposition: This claim seems almost trivial if we think that the temporal experience is characterized by the fact that contents are en- countered not together at once but rather successively. Furthermore, and here it becomes a bit more complicated, Bergson thinks that it is essential to temporal experience that its contents are not at all separated as we spelled it out for juxtaposition: Grasping things or positions sepa- rately next to each other, means to take each of them to stand for itself in a way. However, Bergson tells us that parts of temporal experience, i. e. moments, can’t be taken to stand for themselves in the same way (cf. [5, p. 99-102], [3, p. 74-76]). Or at least they can’t without disregarding an aspect that seems to be an important one for their being structured in a temporal way and which has to do with the interdependence of mo- ments: From Bergson’s view the ‘elements’ of an experienced temporal succession are interconnected and organised among each other in a way that is in turn essential to every individual element, i.e. moment itself. Considering moments as sharply distinguished from each other and as isolated from their being bound into the succession is only possible by 112 KRITERION – Journal of Philosophy, 2016, 30(2): 107–124

‘abstract thought’ [5, p. 101] (cf. [3, p. 75]) - and this abstraction means just to prescind from the temporal structure of our experience. A well known, vivid example in this context is the listening to a melody (cf. [5, p. 100 et seq.], [3, p. 75 et seq.]). To describe the experience one has at a certain moment of the listening, it doesn’t seem to be appropriate to take the single tone as standing for itself and being separated from the others. Consequently, we do not seem to grasp all aspects of the melody if we conceive it exclusively as a series of discretely juxtaposed tones. If you think, for example, of the harmonic resolution of a dissonance heard before, it becomes clear that the experience of the presently perceived tone is not separable from the experience of the previous tones: as Bergson puts it, they ‘permeate one another’ [5, p. 100] (cf. [3, p. 75]). Building on this concept of moments being closly connected among themselves, it seems that the continuity of their aris- ing from each other plays a particular role when it comes to temporal structure. In contrast to spatial contents that present themselves as together and separated, temporal contents, therefore, seem to be presented suc- cessively on the one hand and closely connected among each other on the other hand, where this inner connection can be specified as a perme- ation of moments or as their continuous development from one another. Of course, these notions of ‘permeation’ and ‘continuity’ are still un- clear. Remember, however, that until now we are not yet talking about metaphysics but about the structure of our temporal experience. It is thus not problematic to specify these notions as qualitative ones: it is with respect to the way of how I experience one single tone within the melody, that its continuous arising out of the previous series of tones is indispensable.

4 Intellectual practice and spatial structure

I will now focus another observation that becomes apparent in connec- tion with Bergson’s reflections and that will be important for my issue: Beyond the immediate experience of spatial phenomena, we use the spa- tial structure of juxtaposition to arrange all kinds of mental contents that are not necessarily connected to spatial experience. Hence, regard- less of whether juxtaposition is the objective structure of space or not, it seems definitely true that it plays a role in structuring mental contents and, thus, seems to be part of our own epistemological toolbox (cf. [5, p. 99-137], [3, p. 74-102]). Sonja Deppe: Mind-Dependence of the Relational Structure of Time 113

In order to make this clearer, it helps to consider a more virtual form of juxtaposition. We have the ability to take into account different things together, but separately. In fact, Bergson believes that this ability is essential to our intellectual capacity. He claims that the structure of juxtaposition is involved in many activities of human intellectual practice in a constitutive way. Consider for instance the practice of counting and quantification, within which Bergson sees the spatial structure of accumulation and differentiation to be represented in a most explicit way: Imagine for instance a shepherd counting the sheep of his flock (in the meadow or in his mind). From Bergson’s view, in order to do so, he needs to juxtapose his sheep within a spatial structure: they have to be set separately - in order to form units - and together - in order to form a sum (cf. [5, p. 75], [3, p. 57]). One might object that temporal structures may serve the same pur- pose as well.4 When, for instance, the shepherd counts the flock point- ing at (or thinking of) the sheep one by one this process of counting seems to use time instead of space to separate the sheep. Considering this objection, Bergson points out that spatial, juxtaposing structure is nevertheless relevant in this case - otherwise we would not succeed in accumulating, adding up and hence counting the sheep. He says:

For if we picture to ourselves each of the sheep in the flock in succession and separately, we shall never have to do with more than a single sheep. In order that the number should go on increasing in proportion as we advance, we must retain the successive images and set them alongside each of the new units which we picture to ourselves: now, it is in space that such a juxtaposition takes place and not in pure duration. [5, p. 77] (cf. [3, p. 57-58])

Obviously Bergson doesn’t mean that every time we are counting or calculating we have to create explicitly a mental picture representing the objects to be counted next to each other within an ideal space. What he tries to show us, however, is that, in principle, our ability of quantitative thought depends on spatial structuring. In a similar way as in the context of counting, we could spell out the actual or virtual use of a juxtaposing structure in the context of comparing things: Only considering things at once but separately allows us to ascribe equal or different properties to them. Comparison in turn plays an important role within the practice of classifying entities, and 114 KRITERION – Journal of Philosophy, 2016, 30(2): 107–124 again classification is an important feature of language. Hence, classifi- cation and many aspects of language depend ultimately on juxtaposing structures (cf. [5, p. 97], [3, p. 73]). Bergson uses another term to describe the structure of grasping things together and separately: actual or virtual space allows us to per- ceive or conceive things as being ‘external to one another’ [5, p. 99] (cf. [3, p. 73]). Considering different sheep at a time, they are obviously not allowed to permeate each other if we are going to count, compare or clas- sify them. Bergson asserts rather that ‘externality is the distinguishing mark of things which occupy space’ [5, p. 99] (cf. [3, p. 73]). Here it becomes clear that as a matter of fact Bergson thinks spatial and temporal structure to be properly opposed to each other: In contrast to spatially structured contents, the contents of our temporal experience, i.e. the experienced moments, are never really external to one another. We saw this in the case of listening to a melody: within the hearing- experience of the single present tone itself the preceding tones played an indispensable role. Besides the fact that temporal moments appear to be ordered in a successive way (rather than being presented together at once), they were hence characterized as being closely connected among themselves. The crucial feature of temporal structure, from Bergson’s perspective, is that the experience of the present moment is only to be understood against the background of past moments. The term ‘external to one another’ illustrates in what way for Bergson applying a juxtaposed structure also concerns the possibility of taking objects to stand for themselves, of considering them ‘as such’, i.e. (at the greatest possible extent) independently from our own situational - and hence temporally bound - experience of them. Here we get an idea of how even our intellect’s focusing upon abstraction and objective thought might require contrasting juxtaposition and hence the capacity of spatial structuring. Bergson points out:

indeed, if we notice that abstraction assumes clean-cut distinction and a kind of externality of the concepts or their symbols with regard to one another, we shall find that the faculty of abstraction already implies the intuition of a ho- mogenous medium [i.e. space]. [. . . ] This latter, clearly conceived by the human intellect, enables us to use clean-cut distinctions, to count, to abstract, and perhaps also to speak. [5, p. 97] (cf. [3, p. 72-73]) Sonja Deppe: Mind-Dependence of the Relational Structure of Time 115

5 Spatial structuring within the context of acting

In the previous section we saw how the practice of applying juxtapo- sition is a powerful tool of our intellect in order to represent contents in a structured way and - as we will see now - to render them more easily accessible for possible actions. Indeed, it is Bergson’s idea that the tendency of our mind to structure phenomena in a spatial way is ultimately owed to practical needs. For him, it is the context of acting that demands dealing with differentiated states: namely, they can be starting positions, motivations or targets of an action. Let us have, for instance, a closer look upon the role of results and/or our reference to them within our acting: The function of the intellect is to preside over actions. Now, in action, it is the result that interests us; [. . . ] and thence it comes also that only the goal where our activity will rest is pictured explicitly to our mind: [. . . ] Let us con- sider a very simple act, like that of lifting the arm. Where should we be if we had to imagine beforehand all the elemen- tary contractions and tensions this act involves, or even to perceive them, one by one, as they are accomplished? But the mind is carried immediately to the end, that is to say, to the schematic and simplified vision of the act supposed accomplished. [. . . ] The intellect, then, only represents to the activity ends to attain, that is to say, points of rest. [2, p. 325] (cf. [4, p. 298-299]) The idea seems to be the following: very well may the execution of an act be a continuous process; when considering the act, planning it, or ticking it off, however, we have the tendency of grasping it as a leap between different states. But how do we obtain the conception of those states that serve as point of action on the one hand and as aimed outcome of our acting on the other hand? This is a crucial point in Bergson’s reflections: What we need here is situations grasped as external to one another. In order to apply our acting correctly, we have to juxtapose its starting position and its desired result. So, what does not help us here is a view that takes into account the continuous arising of one situation out of another, i.e. a temporally structured view in Bergson’s sense. Rather a juxtaposing approach to the temporally structured experience is required. In the first place this context clarifies again that applying a jux- taposing structure to our experienced contents is a useful tool of our 116 KRITERION – Journal of Philosophy, 2016, 30(2): 107–124 intellectual practice, its use lies in preparing our action. In the second place, however, we see here that for practical reasons we have the ca- pacity (and actually the tendency) to apply the method of juxtaposing contents even to contexts of situational processes, and hence to the tem- poral experience itself - although, as we saw above, this latter one is originally not at all structured in a juxtaposed way. In the next section I will address this step in more detail.

6 Spatial grasping of temporal phenomena: the cinemato- graphic mechanism

Above, we encountered spatial and temporal structures as two distinct and even opposed approaches to experienced content (ignoring for a start the question if they are structures of the world itself as well). With a closer look to the context of our acting, however, we found a context within which a connection between those structures seems to be estab- lished. Indeed, in Bergson’s view, in this context temporal structure appears to be translated into spatial structure; for the juxtaposing ac- cess to our temporal experience is a way of structuring it as a preparation for possible actions. Hence here spatial structure comes into play only as a secondary structure imposed by our mental capacities on our original temporal experience. Bergson’s idea can be illustrated by the image of single moments that are cut out of the continuous stream of temporally structured experience and its mutually permeating contents. Certain single situations are (e.g. in memory or in anticipation) pulled out of their binding within the successive continuity of temporal experience in order to consider them as separated and standing for themselves and to juxtapose them to others. While originally we had to do with a continuous, interwoven whole of on-going processes, we can now (turning towards practical regards) grasp isolated states, which allows us in turn to conceive several of them at once - together but separate. In his later book Creative Evolution Bergson compares such an ap- proach of cutting out single moments with the mechanism of a film cam- era, taking instantaneous pictures out of the continuous progression of events to be filmed. By fixing the pictures within the film reel, moments are taken out of the temporal succession of the events and transferred to the structure of a simultaneous juxtaposition. Furthermore, the inner bond of the processes is detached and the images are positioned external to one another, hence standing for themselves, instead (cf. [2, p. 330 et Sonja Deppe: Mind-Dependence of the Relational Structure of Time 117 seqq.], [4, p. 303 et seqq.]). However, just as in the case of the film camera, it seems obvious that such a cutting out is attended by a reduction with respect to the original content experienced in the continuous form of duration. Of course, such a reduction is not necessarily a defect: In the context of acting, it is rather an advantage according to the motto ‘less is more’.5 However, - and now I will turn back to metaphysics - what Bergson considers as problematic is a philosophical practice that takes exclusively those contents of experience as a basis for metaphysical reasoning that are gained by our spatial juxtaposing access to experience.

7 The metaphysical status of the relational structure of time

As I already said, I consider the crucial task within the metaphysics of time to identify the essential structure of time. We encountered this question also within the conception of Henri Bergson, who brought into play two structural patterns gathered from observing our original spa- tial and temporal experience. I contrasted them as mutually external juxtapostion on the one hand and mutually permeating successivity on the other hand. Following Bergson’s approach it seems obvious that the structure of juxtaposition comes off badly as a candidate for being the essential structure of time (regardless of the fact that it possibly does well for the essential structure of space): Firstly, from his view, our experience argues against it. Secondly, his reflection about the mind gives us a con- vincing explanation of how, within the temporal context, the structure of juxtaposition may come into play only subsequently. Bergson hence unmasks juxtaposition as secondary here. As you probably suspected, Bergson tends to expose somehow succes- sivity and the inner connection of moments to be the essential structure of time. Before we can support or reject this claim, however, there will be many questions to be answered.6 This is not the topic of this pa- per. What I take from Bergson here is the negative claim disclosing the unplausibility of juxtaposition to be the essential structure of time. Let us bring again into focus the relational B-structure, expressed by the notion of earlier/later, that the tenseless theory of time takes to be the essential characteristic of time. With Bergson’s conception at the back of our mind, let us have a closer look to what is involved in thinking of time as relationally structured. 118 KRITERION – Journal of Philosophy, 2016, 30(2): 107–124

In order to establish a relation between two moments of time, un- derstanding one of them as ‘earlier’ and the other one as ‘later’, we need to grasp them on a par with each other in the first place. Two self-contained elements are considered ‘in one go’ when related to each other. This means that in order to do so we need an access to time that allows us to take into account several moments together and separately. Putting moments together and separately is exactly what the B- theory does: It is a cornerstone of every B-theoretic approach to treat all B-times on a par with each other, neither of them ‘ontologically priv- ileged’ [8, p. 332]. Furthermore every such time stands for itself and can be considered independently of others. (This becomes clear if you think about the variable applicability of the earlier/later relation: any two times can be put in this relation while all remaining moments of time can be faded out.) Relating different moments of time and locating them within the ear- lier/later scheme of order, hence, presumes grasping them as juxtaposed to each other in Bergson’s sense. So then the relational structure of time involves juxtaposition.7Actually, Bergson, far from being familiar with B-theory, makes this point very clear: ‘we could not introduce order among terms without first distinguishing them and then comparing the places which they occupy; hence we must perceive them as multiple, si- multaneous and distinct; in a word, we set them side by side, and if we introduce an order in what is successive, the rea- son is that succession is converted into simultaneity and is projected into space.’ [5, p. 102] (cf. [3, p. 76]) The expressions ‘converted’ and ‘projected’ lead us straight to our question of the metaphysical status of the B-structure: Is it really con- vincing to take this structure that presupposes juxtaposition to be an essential part of the structure of time, as B-theorists would have it? Or is it more plausible to conceive of it as a structuring belonging to our own access to time as Bergson implies? Let us recall Bergson’s line of argument and relate it more directly to the B-theoretical approach. Firstly Bergson pointed out that our immediate experience of tem- poral phenomena is originally structured in a way that moments (and things belonging to those moments) are noticed/ encountered/ grasped as strictly successive (in contrast to together at once) and permeating one another (in contrast to external to one another). Hence juxtapo- sition is not involved. So he makes clear that a juxtaposing access to time does not arise from our original temporal experience: we do not Sonja Deppe: Mind-Dependence of the Relational Structure of Time 119 experience different moments on a par with each other, in contrast to our experience of different places in space. Indeed, this seems to be true: we never encounter different moments of time ‘on an equal footing’ with each other, but - in experience - there has one moment an exeptional position, namely the present. This con- nection between our experience and its present is admitted even by B- theorists, feeling therefore constrained to establish a B-theoretic expla- nation for it (cf. [13, p. 44]). No matter what temporal phenomenon you take: Its temporal character in experience comprises the fact that its parts are not given all at once, but - almost too trivial to mention it - successively. It is true that other moments than the present one do play a role within our experience - though this role does not seem to be on equal footing with the present moment. Rather their significance seems to lie within their connection with the present moment, i.e. their influence on it. Hence, Bergson’s first argument against the thesis that juxtaposition plays the key role in temporal structure, which is based on the analysis of our temporal experience, seems to be quite applicable to the B-structure: Our experience does not exactly commend a structure of moments stand- ing separately at a level with each other, hence B-structure. This in- sight, however, is by no means new but rather a standard objection of A-theorists against B-theory. It alone, of course, is uncomfortable but not necessarily an insuperable obstacle for the tenseless theory of time whose metaphysical position avowedly takes some distance from our ex- periential access to time.8 Therefore, it is even more important to consider Bergson’s second argument. Instead of just doubting juxtaposition to be the structure of time, he gives a consistent explanation of why one could misleadingly think so. His reflections on human intellectual practice gave us an idea of how the structure of juxtaposition (that initially had been associated with space within the immediate experience) plays furthermore an im- portant role when it comes to the arragengement of mental contents by our mind. In this regard we encountered juxtaposition not just as a form of experience but rather as an epistemological tool, that, by the way, proves to be useful in practical contexts. What is important to see is that in those cases we encountered juxtaposition as a secondary struc- ture imposed by our mind in order to cope with contents not necessarily spatial in nature. Does this apply as well to the relational structure of time, which already has been exposed to depend on juxtaposition? Imagine, just hy- 120 KRITERION – Journal of Philosophy, 2016, 30(2): 107–124 pothetically, that the beforehand described original experience of time of successivity and permeation of moments would be our only access to temporal phenomena. This would indeed not be very useful in practical respects: On the one hand, by virtue of the moment’s successivity, we would strictly have to do with the single moment just experienced and hence be unable to refer to any other moment. Reflecting on past expe- riences or directing our actions towards future targets would be hardly possible. On the other hand, even if we had to do with a single mo- ment here, this one would be embroiled and permeated with other, now vanished, moments, since it would be qualitatively stamped by its con- tinuous emergence from other moments as we saw it in the case of the melody. What would be missing here is the capacity of conceiving a moment as a bare state that is comparable to others and possibly repro- ducable. This, however, seems to suspend the possibility to evaluate a moment as the result of certain actions or to use it as starting points for calculated actions, as has been developed in Section 5. Sure enough, in this hypothetical situation a mental approach of isolating moments as states, confronting them with others and arranging the ensemble within an ordering scheme would do a great deal: We will be able to repeat successful actions or avoid unsuccessful ones if we have the possibility to isolate once experienced moments as standing for themselves, to confront them with the present experience and to conceive of the interaction between them as an ensemble of earlier and later states. We will be able to direct our acting in an advantageous way, if we put ourselves in the position to conceive of a desirable state while experiencing another one, to reflect their differences and to grasp both as (possibly) related as one earlier than the other. Establishing this approach of taking into account situations as external to each other would obviously go along with juxtaposition, since moments have to be conceived of as separated and together, as already pointed out. This setting may give an idea of how the juxtaposing structure of an earlier/later ordering of moments in fact facilitates our handling of time within our everyday acting. Within this exposure, however, the relational structure appeared to be merely secondary, applied by us to our original experience. Following up on the above example of a melody, a quite good illus- tration for this procedure would be the compilation of a sheet of music: On the one hand, every single tone is reduced here to an isolated state that is perfectly reproducable detatched from its being bound within the succession with the others. On the other hand, the succession of tones Sonja Deppe: Mind-Dependence of the Relational Structure of Time 121 is being fixed, too, although not within the original temporal (successive and permeating) form any more, but rather within a juxtaposititon of an ensemble of elements on a par with each other. As follows from the illustration, successivity and inner connection as experienced in temporal phenomena can be brought to a juxtaposition form which turns out to be useful in many respects. But writing down the tones of a melody on a sheet obviously is a matter of conceptualising the melody mentally, which in itself can only be revived by playing its notes successively and allowing the tunes to permeate each other within temporal continuity. The view elaborated here results in a very plausible alternative for the status of the B-structure within the field of time: As I see it, B- theory converts experienced successivity and continuous emergence of moments into ordered and easily accessible juxtaposition in a similar way than a sheet of music does with a melody. In this light, the B- structure seems to be part of our own grasping of time rather than of time itself (even if we may not know the latter one’s positive structure yet). Hence, in line of this reasoning, the relational structure of time, the objectivity of which is the cornerstone of the metaphysical position of tenseless theorists, appears to be mind-dependent. In this paper I wanted to render plausible a view that conceives the relational B-structure as a feature belonging to our own structuring access to the world. In doing so the metaphysical relevance of the B- structure has been challenged, which may be a step in the search of the essential structure of time. Since my focus lied on the B-structure I did not provide any direct argument to support the metaphysical relevance of the A-structure. Confronting its approach with Bergson’s reflections on temporal structure in a similar manner seems to be a further interesting issue - that will be left for another time.

8 Conclusion

I have consulted the reflections of Henri Bergson about our original tem- poral experience on the one hand and about the tendency of our in- tellectual practice to apply spatial and juxtaposing structures on the other hand. With regard to these considerations, we arrive at the fol- lowing conclusions: Firstly, a juxtaposing and hence spatial structuring of time seems to be secondary with respect to our original experience of time. Secondly, the alleged relational structure of time - presuppos- ing juxtaposition - seems to be more closely connected to the nature of 122 KRITERION – Journal of Philosophy, 2016, 30(2): 107–124 our intellect than to the nature of time itself (whatever that is). Thus my considerations suggested understanding the relational B-structure of time primarily in the context of our structuring access to and handling of temporal reality. Hence, with respect to tenseless theorists - whose aim is to discredit the metaphysical importance of the A-structure of time for the reason of being merely mind-dependent - we find an interesting result: from Bergson’s perspective, their own starting point of metaphysical reflec- tion, namely the relational structure of time, seems itself to depend on the human mind.

Notes

1 I will use ‘A-structure’ as abbreviation for ‘structure that can be described by A-notions’ and ‘B-structure’ as abbreviation for ‘structure that can be described by B-notions’. 2 It is true that Oaklander broaches the issue of an ‘ontological ground of temporal relations’ [14, p. 74]. This is, however, in order to refute the presentist premise and hence part of the debate on the metaphysical status of the A-structure as well. 3 For reasons of simplification I will not discuss here the proper notion of ‘duration’ that Bergson introduces in order to distinguish his own conception from a con- ventional use of the notion ‘time’. For him, the latter one is usually understood with a close connection to space which Bergson wants to avoid. 4 For instance, Rudolf Carnap even tries to trace back the practice of counting to successive experience in principle (cf. [6, p. 15]). For Carnap’s approach to time and measurement see also [9] (this volume). 5 By the way, Bergson counts even scientific reasoning as a form of praxis, since the target of its analytical activity is to structure experienced contents for practical action. Furthermore, its methods and systems of concepts are structured in a spatial way in Bergson’s sense (cf. [2, p. 357 et seq.], [4, 328 et seq.]). 6 For instance there is obviously a requirement of a more precise characterisation of this structure. Furthermore it has to be asked how a metaphysical dimension of the mutual permeation of moments - beyond a mere subjectivly experienced quality - is justified etc. 7 A possible objection here might be that the term ‘juxtaposed’, meaning ‘next to each other’ indicates a spatial relation in the first place and that its use in the temporal context should be taken as a mere figurative sense. The opponent might point out that the relation of earlier/later is intended to describe a temporal connection after all and hence - even if moments are considered together at once - they are never put ‘next to each other’ in last consequence but ‘past each other’ which still allows for their successivity. Remember, however, that we worked out from Bergson’s conception how in or- der to conceive entities together but separated the spatial dimension is already involved (Section 4). Successivity may be the starting point of applying the B- theoretic order relation - however, just by taking successivity to be a mere order Sonja Deppe: Mind-Dependence of the Relational Structure of Time 123

relation (of a whole entirely given ‘succession’), it is reduced severely and ac- tually deprived of the temporal character as we are acquainted with from our experience. 8 The validity and/or plausibility of the reasons for this distance are actually part of the debate between A- and B-theorists. They are, however, not the main focus of this article.

Sonja Deppe Universit¨atKoblenz-Landau Institut f¨urPhilosophie B¨urgerstr. 23 76829 Landau (Pfalz)

References

[1] Lynn Rudder Baker. “On the Mind-Dependence of Temporal Becoming”. In: Philosophy and Phenomenological Research 39.3 (1979), pp. 341–357. [2] Henri Bergson. Creative Evolution. New York: Random House, 1944. [3] Henri Bergson. Essai sur les donn´eesimm´ediatesde la conscience. Paris: Presses Universitaires de France, 1946. [4] Henri Bergson. L’´evolutioncr´eatrice. 8th ed. Vol. 8. Paris: Presses Universitaires de France, 1998. [5] Henri Bergson. Time and free will: An essay on the immediate data of consciousness. Mineola and N.Y: Dover Publications, 2001. [6] Rudolf Carnap. Physikalische Begriffsbildung. Vol. 39. Wissen und Wirken. Einzelschriften zu den Grundfragen des Erkennens und Schaffens. Karlsruhe: G. Braun, 1926. [7] William Lane Craig. The Tensed Theory of Time: A Critical Ex- amination. Dordrecht: Kluwer Academic Publishers, 2000. 124 KRITERION – Journal of Philosophy, 2016, 30(2): 107–124

[8] Heather Dyke. “Time and Tense”. In: A Companion to the Philos- ophy of Time. Ed. by Heather Dyke and Adrian Bardon. Vol. 52. Blackwell Companions to Philosophy. Oxford: Wiley-Blackwell, 2013, pp. 328–344. [9] Florian Fischer. “Carnap’s Logic of Science and Reference to the Present Moment”. In: Kriterion 30.2 (2016). [10] Cord Friebe. Zeit - Wirklichkeit - Persistenz: Eine pr¨asentistische Deutung der Raumzeit. Paderborn: mentis, 2012. [11] Robin Le Poidevin. Change, cause and contradiction: A defence of the tenseless theory of time. Basingstoke: Macmillan in association with the Scots Philosophical Club, 1991. [12] J. Ellis McTaggart. “The Unreality of Time”. In: Mind XVII.4 (1908), pp. 457–474. [13] D. H. Mellor. Real time II. London and New York: Routledge, 1998. [14] L. Nathan Oaklander. “Presentism, Ontology and Temporal Expe- rience”. In: Time, Reality & Experience. Ed. by Craig Callender. Cambridge: Cambridge University Press, 2002, pp. 73–90. Lucretius On Time and Its Perception

Pamela Zinn

Abstract This paper analyzes the ontology and epistemology of time in Lucretius’ De rerum natura. It uses the physiology of perception as well as epistemology to shed new light on the metaphysics. It presents an exegesis-based interpretation of the nature of time and of its perception, both arguing for and refining this interpretation by showing its explanatory power. The paper shows that Lucretius represents the perception of time or sensus temporis as a distinct sensory faculty, reconstructs how it emerges and operates, and relates it to his account of perception more generally. The sense of time in turn is seen to explain aspects of related faculties, including thought and sight, and cases of apparent simultaneity. The paper thus contributes to, among other things, our understanding of the speed of perception and Lucretius’ account of the nature of time itself — arguing that Lucretius represents time as both continuous (not atomic) and real, as well as something perceived.

Keywords: cosmogony, divisibility, dreams, past-presentist, simultaneity

What is the nature of time and how do we come to know it? From Zeno’s paradoxes to Diodorus Cronus to Einstein’s theory of relativity, the physics and metaphysics of time have been a lively topic of debate — as is the Epicurean position on it. Much of the surviving evidence pertaining to Epicurean philosophy of time is testimonial or fragmentary. Lucretius is our best witness, though his account cannot be assumed to represent the views of the school as a whole. Much scholarly debate has focused on the nature of time. Scholars such as Bailey, Sorabji, Asmis, Morel, and Gœury have argued that Epicureans regarded time as atomic — i.e.: that time exists as a series of ‘time-atoms’.1 Warren, for example, has cast doubt on this, as well as on the past-presentist position that for

Kriterion – Journal of Philosophy, 2016, 30(2): 125–151. http://www.kriterion-journal-of-philosophy.org c 2016 The author 126 KRITERION – Journal of Philosophy, 2016, 30(2): 125–151

the Epicureans time is an infinity of nows or instants, wherein the past only exists relative to the ever-fleeting present.2 This paper starts from the claim that Lucretius’ account of time in De rerum natura (hereafter DRN ) focuses less on its nature and more on how it relates to our sensory faculties. The latter is generally underestimated in scholarship on time in Lucretius. This paper offers an analysis which takes both his ontology and epistemology of time into account and shows how they inform one another. It approaches time in DRN by following Lucretius’ lead and reconstructs his theory of the perception of time. In other words, the paper analyzes time through the mechanisms by which we know it, as Lucretius represents it. The paper begins by analyzing Lucretius’ account of the ontology of time, establishes that the perception of time is a distinct sensory faculty, and analyzes the metaphysical relationship between time itself and the sense of time. A discussion of some implications of this analysis follows. Next the paper situates the perception of time in the context of his theory of perception more generally. It then reconstructs Lucretius’ account of how the perception of time operates in relation to its underlying psychophysiological mechanisms, using particular examples. In turn, it shows how our sense of time explains aspects of such mechanisms and cases of apparent simultaneity. Thus the paper sheds light on the speed by which the faculties of living creatures operate and contributes to our understanding of Lucretius’ account of the nature of time itself — arguing that Lucretius represents time as both continuous (not atomic) and real, as well as, ultimately, something perceived.

1 The Ontology of Time and Its Perception

The first deep engagement with time in DRN comes in the context of Lucretius’ discussion of Epicurean metaphysics; the crucial lines for our purposes are 1.418–82. He establishes that the universe consists of two fundamental natures: body and void.3 Place and space are different ways of conceptualizing the void.4 Body includes atomic matter, for which Lucretius has a number of names including primordia or first-beginnings. Body also includes concilia, i.e. assemblies or assemblages of matter which generally form through natural law and are distinct in nature from their constituent primordia; concilia range in scale from something like molecules, to living creatures, to the Earth itself. Only body and void exist per se,5 and only primordia and void exist forever. Everything which is not either body or void, according to Lucretius, is a property of Pamela Zinn: Lucretius On Time and Its Perception 127

one, the other, or the combination of both. Some properties are essential to the fundamental nature of a thing and coexist with it; these he calls coniuncta. Other properties can change without the thing ceasing to exist as such; these he calls eventa.6 Concilia, in a sense, are eventa of primordia and void together, in their temporary arrangement. A coniunctum of a concilium is also an eventum in that it can only exist for as long as that concilium does. Motion is an example of a property which is essential, e.g. to the nature of every body in the void, but the type of motion which a body manifests frequently changes; motion is thus a coniunctum whose particular manifestation is an eventum. Lucretius introduces the nature of time in his account of coniuncta and eventa, and these concepts inform its ontology. For Lucretius, time is not some third nature (in addition to matter and void); it does not exist on its own7 — nor, as we will see, is it a concept constructed by one’s ratio. Time is a property which one perceives.

tempus item per se non est, sed rebus ab ipsis Time likewise does not exist per se, but the consequitur sensus, transactum quid sit in aevo, sensus arises from things themselves — tum quae res instet, quid porro deinde sequatur; namely from what has been in the past, then nec per se quemquam tempus sentire fatendumst what thing is present, further what follows semotum ab rerum motu placidaque quiete next. Nor must it be confessed that anyone DRN 1.459–638 perceives time per se, separated from the motion and calm rest of things.

Lucretius contrasts tempus with per se entities, both ontologically and with respect to perception. The ontological contrast suggests that ‘rebus ab ipsis’ refers to (and is in apposition to) ‘transactum ... sequatur’: what has existed in the past, what does exist in the present, and what will come into being in the future.9 Lucretius does not use the term ‘sense of time’ or sensus temporis, but the concept is clearly present here in the idea that time can be perceived, e.g. ‘sensus’ (1.460) and ‘tempus sentire’ (1.462).10 Since Lucretius is discussing these categories with reference to what is perceivable, and since eternal per se entities are not, he probably means ephemeral things — namely macroscopic concilia and their coniuncta and eventa.11 These lines indicate that this sensus also arises from their motions relative to one another.12 Moreover, the judgment of motion — e.g. that the sun is higher in the sky at noon than it was at sunrise — is, by implication, predicated on one’s ability to remember the relative positions which one has perceived. Similarly to note that any given sensus continues, stops, starts, or otherwise changes, one must recall what came before it. The perception of time is thus to some degree contingent upon other sens¯us, 128 KRITERION – Journal of Philosophy, 2016, 30(2): 125–151

memory, and the comparative function which memory at least partially enables; accordingly — and because, as we will see, it is a faculty of the animus — today one would probably call it a form of cognition. To elaborate: apparently contingent upon some degree of memory, the perception of time operates by perceiving the relational sequences of other sens¯us — specifically that certain perceptions occur and how these other sens¯us change (or are maintained) relative to one another. In other words, the sensus temporis emerges from other perceptions and their relationships. For instance, one is aware of both the sun and its changing position in the sky; we perceive that the sun moves across the heavens and call that interval of time ‘one day’. One also perceives that, over the course of a longer interval, the sun’s motions change angle with respect to the Earth; the interval required to return to its apparent starting point is called ‘one year’. The implication is that without a degree of memory, this would not be possible, as one would not be able to compare the present perception of the sun’s position to the one of five hours ago, much less of five months ago.13 This corresponds to how Lucretius generally represents time throughout the poem, i.e. using, as Berns notes, metaphorical language related to spatial intervals, movement, and the compelling of change according to natural law.14 In the same metaphysical discussion, Lucretius represents the deeds of human beings as movements of concilia upon which the sensus of time is based, helping us to further refine our understanding of the ontological status of time and its perception. Lines 1.464–82 effectively provide examples to further clarify the ‘rebus ab ipsis’ of 1.459.

namque aliud terris, aliud regionibus ipsis For whatever will have been done in the past eventum dici poterit quodcumque erit actum. will thereafter be able to be called an eventum denique materies si rerum nulla fuisset — of the world on the one hand and of its nec locus ac spatium, res in quo quaeque geruntur regions themselves on the other. Furthermore, DRN 1.469–72 if no matter for things, nor the place and space in which each thing is conducted, had existed

. . . never would the feelings, deeds, or wars of men have taken place,

perspicere ut possis res gestas funditus omnis with the result that you are able to observe ... that absolutely all things done ... you may ... merito possis eventa vocare justly call eventa of body and the place in corporis atque loci, res in quo quaeque gerantur which each thing is conducted. DRN 1.478, 81–2 Whether one is speaking of the deeds or res gestae of primordia in the void or of the res gestae of creatures on the Earth, one is still speaking of eventa. The latter deeds, from one point of view, are temporary properties or eventa of concilia; the concilia in question are creatures and places, Pamela Zinn: Lucretius On Time and Its Perception 129

as well as, by analogy, the effective grouping of these. These deeds are thus by definition eventa of eventa.15 One’s perceptions of these things are likewise eventa of eventa. Therefore, contra Bailey, this is no special ontological category.16 Moreover, as Verde rightly emphasizes in relation to the ontology of time, eventa do not have a lesser claim on reality.17 Generally speaking, in contrast with Democritus (e.g. B9 Diels-Kranz), Epicureans claim that not only atoms and void, but also properties, are real — not mere convention.18 For Lucretius, coniuncta and eventa exist; as we have seen, they simply lack independent existence.19 Eventa of eventa are also real. Both Lucretius and Epicurus discuss time in the context of the ephemeral properties of per se entities. Whereas Epicurus focuses the discussion on atoms and their movements,20 Lucretius focuses on the res gestae of living creatures,21 indicating that his concern lies as much with the perception of time as it does with the nature of time. That said, Lucretius uses similar language when describing primordia and dust-motes, including their wars and contests22 — suggesting that if one could perceive primordia, the same perceptual mechanism would apply and, regardless, that time itself does exist relative to the motions of all corpora. Warren is thus correct that Lucretius is generalizing to all res gestae, at whatever temporal period, in DRN 1.478–82.23 It is therefore possible that Lucretius’ relatively compressed account is not offering a simplified account of Epicurus’ Letter to Herodotus, as Bailey suggests, but rather drawing on a different account(s) from Epicurus, such as that which PHerc. 1413 indicates.24 Alternatively, Lucretius may be presenting his own synthesis of scattered but related content in Epicurus, representing things with different emphasis from Epicurus, or bringing in original analysis — such as by taking the ideas of Epicurus to their logical conclusion, or some combination of the above. It also follows from 1.459–82 that the sense-objects, so to speak, of the sensus temporis are not bodies and their motions; they are the other types of sens¯us which arise from the interaction of these moving bodies both with and within the perceiver25 — like watching the movement of the sun and feeling the surge of an emotion, respectively. To that extent one could say that the sensus temporis is the sensus rerum gestarum. The scope, limits, rising, and setting of the sensus temporis are defined accordingly. The perception of time is the perception of (i) other perceptions, and (ii) the relations between those perceptions — such as sequence and arrangement. The sensus temporis is, therefore, a second order or complex perception and, at any moment, an eventum of eventa.26 130 KRITERION – Journal of Philosophy, 2016, 30(2): 125–151

Thus, pace Verde, the perception of time should be understood in tandem with its relationship to the physiological structures and mechanisms from which the perception emerges.27 We will turn to this shortly. Time itself is not an eventum of eventa or σύμπτωμα of συμπτώματα, as some testimonia suggest;28 only the perception of time is, as we shall see. Lucretius represents time itself as a coniunctum of matter and motion together.29 Asmis is correct that ‘time is . . . the relative duration of properties’30 in the sense that time is eternal (and often referred to as such by Lucretius) relative to the movements of the first-beginnings, even though it lacks independent existence. It actually has quite a strong ontological basis, as the next section will show. Whether anyone is around to perceive it is a moot point, ontologically speaking.

2 Some Implications of the Ontology

For an Epicurean, as Warren shows, the nature of time is intimately bound up with concerns about truth and the avoidance of determinism. Time itself must exist, otherwise the sensus temporis would constitute an error of perception, and, for the Epicureans, the senses are the primary criterion of truth.31 Scholars favoring a past-presentist interpretation of DRN question the reality of the past and future, asserting that only the present moment is real.32 According to Lucretius, of the past, and particularly the distant past (e.g. prior to one’s own existence and thus memory), one has at best vestigia of their existence, by which past eventa may be known — to the extent that they can be.33 These traces include the songs of the poets, writing, and (of time before their advent) traces scrutable by (ali)qua ratio;34 places, such as those involved in the deeds of humans mentioned above, are an example of the last sort,35 as are the results of long-term causal processes to which past eventa contributed — i.e. the cosmos, and each creature as a descendent of its ancestors and the Earth itself. With respect to the future, all we have to go on is our experience of the world and natural law; one can only predict that things will persist, occur, or not in accordance with one’s experience.36 For example, the first humans experienced the alternation of days and nights, so they believed that the sun would always return.37 Even if we personally have not experienced past and future eventa, they still have objective reality during some period of time.38 Lack of experience is only a bar to our potential awareness and knowledge of them now, not to their reality. Finally, as our knowledge of the existence of primordia (among other things) shows, what one cannot perceive is not necessarily unreal.39 Pamela Zinn: Lucretius On Time and Its Perception 131

Past, present, and future eventa and thus — in accordance with the logic of 1.459–82 — past, present, and future time are all therefore real. Lucretius does not mention whether one can have a concept of time itself. Epicurus rules out the πρόληψις of time;40 but, as we have seen, both suggest that one can conceive of measures or units of time (e.g. the day, much, less). Insofar as instances of the perception of time (as opposed to instances of time itself) arise from other particular feelings, those instances can be called eventa of eventa. These ideas of measures of time are common across individuals, suggesting that, despite any subjective factors involved in the underlying perceptions which contributed to their formation, the ideas reflect the same objective reality.41 Moreover, the sensus temporis should be counted among the sens¯us animi because it requires some involvement of memory and can occur during dream-sleep. Some of these points bear clarification and elaboration.

3 The Sensus Temporis and the Senses

How does the perception of time relate to perception and the senses more generally? To answer this, let us take a step back. Lucretius regards every living creature as an entirely material and mortal entity. The life force, so to speak, in each creature is a structure which I call the animus-anima complex. The complex is similar to modern notions of a central nervous system, but one centered in the heart. The animus or mens is the concentration of the complex which lies situated in the heart and constitutes the functional equivalent of what we today might call the brain, intellect, and seat of consciousness. The anima makes up the rest of the complex; dispersed throughout the rest of the body, it operates like the rest of the nervous system. The animus-anima complex and the rest of the living body, together with its network of emergent faculties, make up a generally stable system. Its faculties include sensus. The term sensus, for Lucretius, includes and applies to a number of related things; as Glidden notes, it encompasses αἴσθησις, πάθη, and αἰσθητηρία.42 Thus Lucretius’ use of sensus can signify perception or feeling in general. It can also indicate specific instances of feeling, manifestations of which are experienced through the sense-organs. At times it collectively refers to the sense-organs themselves and to their specific faculties. Sometimes it encompasses multiple meanings at once. The term sensus thus includes: pleasure and pain, the traditional ‘five senses’ (or sens¯uscorporis), and the sens¯us which occur in the animus. These sens¯usanimi recede during certain sorts of sleep and similar states, but, as faculties, they are 132 KRITERION – Journal of Philosophy, 2016, 30(2): 125–151

permanent. They include thought, the emotions, and — crucially for our purposes — the perception of time.43 The sensus temporis can arise from either the sensus corporis or the sensus animi — and, indeed, from both.44 Because it arises from all other perceptions, an instance of this feeling is not contingent upon one’s interaction with a specific sort of sort of external or internal sense-object (or stimulus). If one does not encounter smell-causing particles, one does not experience smell, and, if one does not eat food, one does not experience its taste; nevertheless, the faculties or abilities are present. The sensus temporis, on the other hand, is coextensive with the faculty of sensus itself; not only the ability but also the actual perception of time are coniuncta of this faculty. While awake, one is constantly aware of time, because one never lacks some feelings. Even if one touches no object directly, a flow of those stimuli through which external objects affect the sens¯us is always present, as are ongoing internally relative sens¯us.45 In dreamless sleep, by contrast, when the animus-anima complex has receded and the faculty of sensus has thus diminished to the point of being all-but extinguished, one is then unaware of time. Similarly, we have no perception before birth or after death, and thus no perception of time — yet another reason why death is nothing to us (‘nil igitur mors est ad nos’, 3.830).

4 The Sense of Time and the Speed of Perception

Lucretius’ other references to the sensus temporis, particularly in book four of DRN, shed further light on both itself and on other sensory mechanisms. There are no discrete discussions of the sense of time; it is always presented in tandem with another sense. This is in accord with what one should expect, based on the analysis of the previous sections of this study. Lucretius’ account of the perception of simulacra by the mens, for example, is especially illuminating. Take the case of dreams about dancers. For Lucretius, these dreams are explained by both the perception of simulacra and the perception of time;46 they also clarify the speed at which the latter operates relative to the former, as an underlying mechanism.

quod superest, non est mirum simulacra moveri What is more, it is not marvelous that the bracchiaque in numerum iactare et cetera membra; simulacra apparently move themselves47 and nam fit ut in somnis facere hoc videatur imago; wave about their arms and their other quippe ubi prima perit alioque est altera nata members in rhythm — for it happens that an inde statu, prior hic gestum mutasse videtur. image does seem to do this in dreams. In fact, scilicet id fieri celeri ratione putandumst: of course,48 when the first simulacra have tanta est mobilitas et rerum copia tanta, been absorbed49 and others then have arisen Pamela Zinn: Lucretius On Time and Its Perception 133

tantaque sensibili quovis est tempore in uno in another position, this earlier image seems copia particularum, ut possit suppeditare to have changed posture.50 Obviously this DRN 4.768–76 must be thought to occur in a swift manner: so great is the mobility and so great the supply of these things — and the abundance of particles present in any single perceptible moment is so great that they can be fully supplied.

The adjective sensibilis (4.775) confirms that time is something which one perceives. The phrase ‘sensibili quovis ... tempore in uno’ seems in this context to mean ‘in any given moment’; this is the smallest possible interval of time which one can perceive, and thus the lower limit of the speed of this faculty (in conjunction with memory).51 This is the shortest interval of time which one might call ‘the now’ or ‘an instant’. Relative to perception, it has no past or future extension.52 Now, so construed, is fleeting, gone as soon as it is grasped. To pick up a previous thread, contra the past-presentist position: if Lucretius did not acknowledge the reality of the past and future, i.e. if there was quite literally no time but the present, such a definition of the present moment would have profound epistemological consequences, as well as deny the reality of longer-term causal processes. For example, distant source-objects would no longer be real by the time their emitted stimuli reached a perceiver.53 Source-objects would lose or gain reality as they lost or gained a perceiver. Would their different numbers of perceivers make two source-objects, simultaneously perceived, more and less real relative to one another? Such a position might also imply, by analogy from the perceivable, that only the smallest unit of time on the primordial level is real, thus denying the reality of the perceivable instant.54 However, as we shall see, Lucretius does not hold with such theses. Returning to the above passage, imago at 4.770 stands for two things at once. Firstly, imago refers to the sensus or perceived image, at a perceptible moment; this image arises from a series of interactions between the animus and many simulacra. Secondly, imago refers to the continuous but shifting image summing up the phenomenological perceptions across those moments. In 4.772 (and in 4.801 below), ‘gestum’ carries the implication that this posture, gesture, or position is a snapshot of a larger movement.55 The speed at which one’s interactions with simulacra occur is therefore far greater than the speed at which one perceives time. Lucretius develops these ideas throughout the subsequent twenty- five lines, which contain no shortage of verbal echoes and in some cases outright repetition, alerting us to the connections.56 Com- 134 KRITERION – Journal of Philosophy, 2016, 30(2): 125–151

ing full-circle to the apparent movement of dancers in dreams, Lu- cretius further clarifies how the two sens¯us relate and operate:

an magis illud erit verum? quia tempore in uno, Or will the truth rather be that: because in a quod sentimus,57 id est, cum vox emittitur una, single moment which we perceive, i.e., when tempora multa latent, ratio quae comperit esse, one sound is emitted, many times lie hidden propterea fit uti quovis in tempore quaeque — whose existence ratio discloses. Therefore praesto sint simulacra locis in quisque parata: it happens that, in any moment of time, tanta est mobilitas et rerum copia tanta. every sort of simulacra are present, supplied hoc, ubi prima perit alioque est altera nata in all places — so great is the mobility and so inde statu, prior hic gestum mutasse videtur great the abundance of these things. For this DRN 4.794–801 reason, when the first simulacra have been absorbed and others then have arisen in another position, this earlier image seems to have changed posture.

Taking these lines together with 4.768–76 shows that we experience one continuous image, rather than a series of images, because the perception of time is relatively slow. Modern classical animation, such as in the Disney films of the 20th century, works on similar principles.58 The eye processes more images per second than can be individually distinguished, so the succession of snapshots (or the pictures on cells) of Mickey Mouse appears as a continuous image — which image then seems either stationary or moving, relative to: its own position, the placement and shape of its body-parts relative to one another, and the background against which it is set. The eye seems to see both Mickey Mouse and the background objects at the same time. This is the very sort of process which Lucretius is describing, with the qualification that the objects in the background which one seems to see at the same time would instead be perceived individually by means of their own particular simulacra. Two aspects of the process of vision (here the vision of the animus, as opposed to the eyes’)59 thus highlight the speed of the perception of time. There is some negligible amount of time during which each interaction between the animus and a single simulacrum takes place. There is a similarly minuscule interval of time between when one simulacrum is absorbed and the next comes up for interaction. The interactions thus occur in effectively immediate succession, resulting in the experience of a continuous feeling.60 This analysis has implications for our understanding of the organiza- tion and argument of book four. The order of 4.722–822, and particularly the considerable overlap between 4.768–76 and 4.794–801 above, has been the source of some scholarly contention.61 The structure and echoes here are logical given the philosophical content and context in the poem. Lucretius’ primary topic in these hundred lines is how the speed of the interactions and the thin, fine nature of the stimuli affect the vision of the animus, by analogy with the physiological mechanisms of the vision of the Pamela Zinn: Lucretius On Time and Its Perception 135

eyes. Such is his explanation from nature for why one seems to see the dead and other ‘unreal’ things during sleep and can think of them while awake.62 But an integral part of this explanation is relativity — i.e. the speed of the vision of the animus relative to the speed of the perception of time. The need to bring out this detail justifies the structure. The considerable verbal and conceptual echoes, especially between 4.768–76 and 4.794–801, thus allow the latter to serve as a deliberate point of expansion of the former’s ideas, but with different emphasis. To conclude this section: there are far more intervals of time within an instant than one can perceive.63 Lucretius’ repetition of the ablative of time within which, three times across these two passages and using very similar words, is emphatic. Such intervals can only be conceived of as distinct by ratio (4.796); in other words, they are conceptually divisible.64 Conceptual divisibility does not necessitate that these intervals have an actual limit of division, as bodies do.65

5 The Divisibility of Time Itself

Are there really intervals of time, or only intervals of its perception? The most pertinent ancient evidence concerning the possibility of a belief in time-atoms by Epicurus, and Epicurus’ ideas about time more generally, includes: Sext. Emp. M. 10.142–54, 181–8, 238–47, Simp. In Ph. 934,26, a possible attribution by Demetrius of Laconia in PHerc. 1012 col.31, 4–8, PHerc. 698 fr.23N, and, of course, both Epic. Ep. Hdt. 56–9, 72–3 and PHerc. 1413 [= Arr.2 37]. Barigazzi and Arrighetti attribute PHerc. 1413 to Epicurus’ On Nature 2; Sedley, on the other hand, attributes it to book ten.66 While testimonia are the mainstay of Sorabji’s evidence for a belief in time-atoms, these ancient authors had their own interpretation, agenda and, sometimes, vocabulary.67 As Warren observes, despite the testimonial evidence, the Epicurean references to the times conceivable by ratio and λόγος ‘need not be atomic’.68 Had Epicurus actually posited time-atoms, or — for that matter — space-atoms, it is unlikely that Lucretius would have veered so far in the other direction. Moreover, as we will see, Epicurus’ claim that atoms move at the speed of thought is probably using figurative language. One can reason by analogy from the movements of the smallest perceptible bodies, i.e. dust-motes, to those of the smallest extant bodies, namely the first-beginnings of things.69 Nevertheless, Lucretius’ case for the existence of the first-beginnings is made on different grounds.70 Thus it is implausible, at least with respect to Lucretius, to reason from 136 KRITERION – Journal of Philosophy, 2016, 30(2): 125–151

perceivable instances to the existence of minimal units of time and space, along with the implications of such things for atomic motion.71 In support of the claim that there are no time-atoms, space-atoms, or minimal parts of those units,72 consider also that, for Lucretius, space itself is both infinite and infinitely divisible. There is no physical or conceptual limit to the number of divisions which would divide any particular measure of it (i.e. place), however arbitrarily defined, because no measure of it would lack extension. Time itself is infinite and infinitely divisible in the same way.73 Speed is simply the measure of an interval of space (i.e. distance) traveled over an interval of time in a particular direction. Thus the smallest conceivable distance which one primordium could travel at any angle would still be infinitely divisible and so would the smallest conceivable fraction of time which that journey could require. Therefore the primordia never move in spatial or temporal jerks (i.e. in a jerky or staccato manner),74 even while swerving.75 After all, as we have seen, according to Lucretius primordia move continuously and motion is a coniunctum of body. The most concise evidence that he believes time, space, and motion (in the void) to be continuous is this:

est igitur natura loci spatiumque profundi, Therefore the nature of space and the space of quod neque clara suo percurrere fulmina cursu the vastness exists; the bright lightning bolts, perpetuo possint aevi labentia tractu gliding the perpetual extent of time, cannot nec prorsum facere ut restet minus ire meando run its full course, nor can they make one DRN 1.1002–5 dent in the journey left to travel onwards.

Here, perpetuus seems to mean both continuous and without end, and labor suggests continual motion; if the infinite void were not continuous, such motion would not be possible and perhaps progress might be.76 Thus, pace Morel, regardless of what modality one considers, time itself is continuous.77 The past and future, as the ‘Symmetry Argument’ shows, are also infinite.78 This picture of the infinite divisibility of infinite time and the sensus temporis has consequences for our understanding of Lucretius’ presenta- tion of Epicurean cosmogony and the plurality of all created things. We have seen that an immense number of interactions take place within a perceptible moment — especially in the cases of thought and, as we will see, sight, despite the vast distances which the simulacra may also travel during that moment. Primordia in the void move swiftest of all bodies; their motions seem both constant and so swift as to be virtually infinite.79 Therefore the potential number of interactions between these primordia occurring within any interval of time — moments, days, seasons, years, a lifetime — quickly becomes beyond reckoning. Lucretius posits infinite matter, always moving, at incredible speed, and — above all — in infinite Pamela Zinn: Lucretius On Time and Its Perception 137 time. Interactions become not just possible, but probable. Infinite space is thus no bar to the formation of concilia of whatever size and complexity, including identical worlds.80

6 Simultaneity

If time itself is infinitely divisible, and the sense of time arises from other perceptions, then Lucretius should measure an instant relative to perception, not per se entities. Indeed we find precisely that. As we saw above, lines 4.794–801 clarify that the now or the smallest perceptible moment of time is equivalent to the time it takes to emit one articulated sound (‘cum vox emittitur una’, 4.795).81 As rapidly as this happens, the many steps of the underlying physiological process occur far more swiftly. Circumscribing apparent simultaneity,82 this interval is equivalent to the smallest perceptible change in the relations of things: e.g. with respect to their positions, order, arrangement, motions, interactions, and the rest. Cases of apparent simultaneity are useful for clarifying the relative speeds of the processes underlying our experiences. Lucretius uses the concept of simultaneity to address such questions as: (i) why are we immediately able to think of whatever we wish to, and (ii) why do we see an object instantly when it is placed before a mirror? Take the case of deliberate thought; Lucretius tell us that the mens is able to think of whatever it desires to ‘instantly’.83 There are a multitude of successive interactions in an instant — in this case each with a distinct simulacrum — and corresponding internal interactions occur indescribably fast. Partly for this reason, the mens is apparently able to think of whatever it desires to instantly, even if it cannot move the whole body quite that fast.84 Epicurus claims that the genesis of εἴδωλα occurs at the speed of thought (‘ἡ γένεσις τῶν εἰδώλων ἅμα νοήματι συμβαίνει’).85 However, Epicurus also uses the expression (ἅμα νοήματι) of the motion of atoms in the void, and then goes on to say that atomic movements happen at a speed which only reason can fathom.86 Therefore the speed of thought may simply be figurative language likening their speed to its nearest empirical comparison. As we have seen, there is no speed faster than that of the first-beginnings moving through the void. Regardless, thought occurs extremely fast. Hearing is another revealing example, which also contributes to our understanding of the speed of thought. One seems to hear someone nearby at the same time as that individual emits a word; so speaking and hearing oneself apparently also occur simultaneously.87 This suggests how swiftly 138 KRITERION – Journal of Philosophy, 2016, 30(2): 125–151

hearing-causing bodies move through the air, as well as how swiftly the mechanism of hearing works. Hearing-causing bodies are transmitted through the air more rapidly than smell-causing bodies are, yet far less so than simulacra which interact with the eyes.88 This last, in turn, is much less rapid than the aerial transmission of the simulacra which interact with the animus (or thought simulacra), whose transmission seems generally to occur faster than the speed of light through the heavens.89 The consequent speed of thought is indescribably fast on this reading, particularly given that interaction with but one simulacrum may effect it.90 Nevertheless, due to the limits of the perception of time, the vision of the eyes seems to occur as swiftly as thought does. We see ourselves reflected in the mirror as soon as it is placed before us — apparently instantly and continuously. The whole process of see- ing — the source-object’s shedding of simulacra, their transmission and interaction with the eyes, the experience of sight — all takes place within a perceptible moment.

et quamvis subito quovis in tempore quamque And at any moment, however suddenly you rem contra speculum ponas, apparet imago; may place any thing before the mirror, the perpetuo fluere ut noscas e corpore summo image is visible — so that you learn that fine texturas rerum tenuis tenuisque figuras. structures and fine shapes of things constantly ergo multa brevis spatio simulacra genuntur, flow from the surface of body. Therefore ut merito celer his rebus dicatur origo many simulacra are generated in a brief time, DRN 4.155–60 with the result that the origin of these things is justly called swift. The succession of simulacra which are involved in this sight are both produced and transmitted with extreme rapidity. The constant streaming flow suggests that there is effectively no interval of time, however small, separating the emission of one simulacrum and generation of the next.91 They are continually coming into being, with the corresponding loss of matter for the source object, in however brief a period of perceptible time. Hence an indescribably vast number of simulacra make up a stream, each of which interacts with the eye in one moment of sight. Indeed, sim- ulacra can travel to a much farther mirror without delaying the experience.

hoc etiam in primis specimen verum esse videtur This above all seems also to be true evidence quam celeri motu rerum simulacra ferantur, of with how swift a motion the simulacra of quod simul ac primum sub diu splendor aquai things are borne: the fact that at the same time ponitur, extemplo caelo stellante serena as a sheen of water is first placed beneath the sidera respondent in aqua radiantia mundi. heavens, immediately the serene shining stars iamne vides igitur quam puncto tempore imago in the glittering sky of the world92 are aetheris ex oris in terrarum accidat oras reflected in the water. Do you now see, DRN 4.209–15 therefore, how the image falls instantly from the far reaches of the aether to the boundaries of the earth? One’s agreement with this proof, that the stars’ reflection occurs as the puddle comes into being, relies upon one’s simultaneous perception of Pamela Zinn: Lucretius On Time and Its Perception 139

the puddle and the reflection. Both the speed at which simulacra travel and the physiological mechanism underlying sight are so fast that the entire process of seeing these reflected heavenly bodies occurs within a single perceptible moment. Similar considerations explain the simultaneous experience of other perceptions, like that of an object and its distance from the perceiver.

et quantum quaeque ab nobis res absit, imago And an image93 causes us to see to what efficit ut videamus et internoscere curat; extent each thing is withdrawn from us and nam cum mittitur, extemplo protrudit agitque helps us to distinguish. For, when the image aera qui inter se cumque est oculosque locatus, is sent, it immediately thrusts and drives isque ita per nostras acies perlabitur omnis forward the air — whatever is located between et quasi perterget pupillas atque ita transit. itself and the eyes. And this all slips through propterea fit uti videamus quam procul absit our eyes thus: it both brushes, as it were, the res quaeque; et quanto plus aeris ante agitatur94 pupils and passes through in this way.95 For et nostros oculos perterget longior aura, this reason it happens that we see how far tam procul esse magis res quaeque remota videtur. withdrawn each thing is. And by how much scilicet haec summe celeri ratione geruntur, more of air is tossed before it and the longer quale sit ut videamus et una quam procul absit the breeze brushes our eyes, so much more DRN 4.244–55 distant does each removed object seem to be. Obviously these things are conducted in an extremely swift manner, such that at one and the same time we see what sort of thing it is and how far it is withdrawn.

The respective interactions that give rise to the perceptions of the source- object and its distance from the perceiver must occur in succession, however rapidly.96 These interactions culminate in the perception of one image and its distance for one moment. It is the same moment (una) 97 because the eye interacts with both the stream of simulacra and the air driven by the constituents of that stream at a speed which is extremely rapid relative to the perception of time. What about actual simultaneity? Does it happen? It does in at least one case: death. Death and the permanent cessation of one’s faculties occur at precisely the same time (even at the micro-level) as one reaches a critical dissolution of the animus-anima complex; that arrangement of constituents is integral to a creature’s existence as such.98

Conclusion

In this paper we have seen that time is a property, one which we are capable of perceiving, but whose existence does not depend on a perceiver. Lucretius has the concept of the sense or perception of time — namely of time passing through things happening, to put it colloquially. While the sensus temporis is an eventum of eventa, time itself exists as long as there are bodies moving in the void. As a faculty of living creatures, 140 KRITERION – Journal of Philosophy, 2016, 30(2): 125–151

the perception of time is one of the sens¯usanimi. As an instance of perception, the sensus temporis is a second order perception which entails the perception of other perceptions, and the ability to compare them. These conclusions were supported by a ground up approach — i.e. by reconstructing Lucretius’ account of the sensory mechanisms from which the perception of time emerges. The sense of time elucidated aspects of the other mechanisms, including the speed at which the senses operate. The perception of time is fast, but occurs much more slowly than the perceptions from which it emerges. This explained why one experiences certain things simultaneously. It also explained why one seems to see an object instantly when it is placed before a mirror, and why one is immediately able to think of whatever one wishes to. This reconstruction challenged a number of views common in scholarship on Epicureanism. Lucretius is not a past-presentist; the past, the now, and the future are all real — and both time and motion are continuous, not atomic. Also, so many interactions can occur at the atomic level within a single perceptible moment, that, given infinite time, it is quite plausible that spontaneous collisions in the void brought our world together. These contributions have been made by jointly understanding the nature of time, the experienced perception of time, and the psychophysiological mechanisms underlying its perception, as Lucretius presents them.

Acknowledgements

Many thanks to Monica Gale, Susan Suavé Meyer, James Warren, Stephen McCarthy, and the two anonymous readers from Kriterion for their feedback at various stages of this project, as well as to Gordon Campbell for discussion. My thanks also to the Fondation Hardt for its award of a Young Researcher’s Scholarship in 2014, which was invaluable to its inception.

Notes

1[3], [40], [13], [32], [26] and [27]. 2[48] 3 Lucr. DRN 1.418–21. 4 Lucr. DRN 1.426–7. 5 Lucr. DRN 1.430–48. 6 Lucr. DRN 1.449–58. Pamela Zinn: Lucretius On Time and Its Perception 141

7 Cf. Epic. Ep. Hdt. 72. Barigazzi suggests that PHerc. 1413 fr.81 col.53 may be a comparandum on the issue of time not existing per se or καθ’ αὑτό;[14, 49–50]. Warren’s cautionary remarks on drawing any precise conclusions from PHerc. 1413 are well noted and should be borne in mind in any evaluation of the references to it in this study; cf. [48, 365]. On the interpretation of Lucr. DRN 1.459–82, cf. esp. [48, 368–77] and [7, i.33, 37, ii.25–6]. 8 Quotations from the Latin text of Lucretius’ De rerum natura follow the 1992 edition of Rouse and Smith ([8]) unless otherwise noted. All translations are my own. 9 This reading of Lucr. DRN 1.459–61 falls in between that of [48, 369] and that of [7, i.33]. 10 Cf. [31, 36 n.18] who also uses the expression ‘sense of time’. There is no convenient parallel. 11 Brown’s emphasis would instead render the eventa to which the expression ‘rebus ab ipsis’ refers as ‘occurrences’, seemingly in the sense of ‘events’; [4, 118–21]. Cf. [43, 108], ‘solo a partire dai fenomeni risulta comprensibile la temporalità di quanto si genera e diviene nel presente, nel passato e nel futuro. . . . dall’evento passato, presente o futuro deriva il sensus, la coscienza dell’ temporalità’. 12 Cf. [48, 370]. The relationship between Lucretius’ account and the fragmentary definition of PHerc. 1413 fr.55 col.34 1ff., ‘φαντασία τίς ἐστιν ὁ χρόνος κινήσεως πάσης καταμετρητική’ ([14, 42]), may turn on the relationship between φαντασία and sensus. On Epicurus’ use of φαντασία with reference to time, cf. [32, 201–2]. 13 For a recent interpretation of the various faculties and processes involved in the perception of time, cf. [26]. 14 [15, esp. 477–84]; N.B. her observation that ‘three metaphors of time: force of time, motion of time, and space of time, correspond to the three aspects of nature: matter, motion, and space’ (p.484). 15 Deeds are eventa of eventa in this sense whether one is talking about the motions of a particular body or the motions of a group of bodies relative to one another, such as the internal motions of an actual concilium or of an effective one (e.g. those fighting the war at Troy (Lucr. DRN 1.464–82), or members of a herd watching their well-fed young frolic (1.257–61) — in both cases the group of bodies involved includes the physical location of the creatures). On the possibility that some eventa can involve the relationships among or between concilia, cf. [31, 136 n.17]. 16 Bailey argues that time and occurrences are special types of eventa, and that Lucretius’ target in DRN 1.459–82 is particularly the Stoics; cf. [3, ii.675–80]. 17[43, 96, 106]. 18[34, 33], [44], [46, 7–9, 193–4], [7, i.37]. 19 Cf. e.g. Lucr. DRN 1.449–82, 1.778–81. 20 E.g. Epic. Ep. Hdt. 72–3. But, cf. also Epic. Ep. Hdt. 47–8. 21 Cf. [14, 56]. For example, Paris’ abduction of Helen occurred before the sack of Troy and both things took place long ago relative to the present. Both events are phrased as perfect passive infinitives in indirect statement, substituting for original perfect passive indicatives: ‘Tyndaridem raptam belloque subactas | Troiiugenas gentis cum dicunt esse’ (Lucr. DRN 1.464–5). This emphasizes the fact that these motions occurred with respect to particular bodies — and, as Lucretius 142 KRITERION – Journal of Philosophy, 2016, 30(2): 125–151

goes on to say at 1.466, they were eventa of the people (as bodies). On both points, cf. [48, 370]; for another point of view, cf. [16]. 22 E.g. Lucr. DRN 2.573–4: ‘aequo geritur certamine principiorum . . . bellum’. The greater passage at 2.573–80 compares the war of the first-beginnings (for the generation and destruction of non-living concilia) conducted from infinite time to the birth and death of human concilia which follows upon the alternation of days and nights; this further suggests that time itself exists with respect to the res gestae of all bodies — i.e. living creatures, non-living concilia, and primordia — in the same way. The battle language of the dust-motes at 2.118–21 (e.g. 2.118: ‘proelia’) is similarly emphatic and explicitly analogous to the primordia. 23[48, 374] 24 On PHerc. 1413 [= Arr.2 37], cf. p.135. 25 Sometimes the interactions occurs indirectly, via interaction with intermediary stimuli generated by the source-object. 26 Lucretius seems to assume other second order perceptions as well, such as the perceptions of self, other, and — perhaps — kin, as well as of space or extension. On the possibility of self-awareness or self-perception, cf. [24], [13, 105 n.2]. 27[43, esp. 91–3]. 28 E.g. Demetrius of Laconia in Sext. Emp. M. 10.219 and the report of Aëtius 1.22,5. Both fragments = Usener 294, but in the latter case συμπτωμάτων is a conjecture. Cf. Verde: ‘Il tempo, dunque, è accidente di accidenti perché è relativo ai fenomeni che a loro volta sono accidenti degli atomi e del vuoto’; [43, 112]. For a fuller account of the argument, preserved in Sext. Emp. M. 10.219–27, cf. [7, ii.28–9], who argue that this idea constitutes Demetrius’ interpretation and exegesis of Epicurus. 29 Recall that motion itself is a coniunctum (of body) whose particular manifestations are eventa. This point should perhaps be compared to the fragments of PHerc. 1413 quoted at [14, 53], in light of Sedley’s insight that the term συμβεβηκότα encompasses both coniuncta and eventa; cf. [35]. The conditions of matter’s motion are place and space. Place simply refers to a particular location in space; it has the dimensions of whatever occupies the interval of space. 30 [13, 33]; cf. [48, 364–5], who notes in a similar vein that reference to time’s measurement (e.g. in Epic. Ep. Hdt. 72) ‘is meant to show how, from this primary and earliest impression of temporal change and duration, we come to be able to evaluate other temporal changes by using days and nights as some sort of comparative measure’ (p.364). 31 [48, esp. 263, 377–84]. On the Epicurean dictum that all αἰσθήσεις are ἀληθές, cf. e.g. Lucr. DRN 4.478–9, D.L. 10.32. The literature on the subject is vast; a useful starting point is [42]. 32 For an explanation of this label, cf. p.125. Warren has come down persuasively against the past-presentist interpretation; also on both sides of the past-presentism debate, cf. [48]. Verde has since suggested an intermediate position, namely that the present existence of the past is relative to the evidence of presently existing bodies and their properties, but that the past may have existed relative to a different collocation of entities previously; [43, esp. 112–13, 116–17]. The existence of the past is not contingent upon the present, nor does anything switch its ontological basis in order to maintain existence. Pamela Zinn: Lucretius On Time and Its Perception 143

33 Only to the extent that these vestigia are present and to-hand does one have evidence by which one can infer things about the past and judge whether those inferences are true or false; cf. the concern of [48, 373 n.23] about the reading of [7, i.37, ii.26]. 34 Lucr. DRN 5.1440–7. Cf. 5.324–9, where Lucretius also suggests that the works of the poets are among the traces which the facta virum (cf. res gestae, 5.1444) would have left behind — specifically the bellum Thebanum and the funera Troiae. Lucretius’ reference to the human quest for immortal glory here seems ironic in that it alludes to the quest’s futility. Just as no concilium is eternal, the wars would have left behind many dead, of whom the war was in part an eventum, and their bodies would have provided matter for worms and plants. Taking the two passages together: material traces remain, but — absent verse — they are not generally in any recognizably traceable fashion. Such ideas may contribute to his argument for the value of poetry in that Lucretius is tracing and setting to verse the res gestae of the cosmos, immortalizing them at least relative to the existence of that system of concilia. 35 This does not mean, for example, that Helen’s kidnapping remains extant as an eventum of a place. It happened and thus can thereafter be called an eventum of the place in which it occurred. This move does not give what happened in the past a detached per se existence; it simply acknowledges that it did exist once, however ephemerally, as an eventum of the body and void with respect to which it occurred. Such reasoning concurs with [48, 373] regarding the ‘charitable interpretation’ of ‘Reading (A)’, and support for (A) on p.374, incl. n.24. Campbell, on the other hand, thinks that we can only ‘treat past events as real if we can examine the traces they have left in the present world’ (italics mine); [17, 158]. 36 This precludes the foreknowledge of future contingents, and thereby determinism. Cf. also, perhaps, Epic. Ep. Men. 127. For a clear and plausible account of the Epicurean ‘temporally-relativized view of truth’, particularly with respect to claims about the future, which also takes into account the evidence from Cic. Fat., cf. [48, 377–84, 385]. 37 Early humans initially perceived the regular alternation of days and nights and thus experienced no fear that day would not return; rather their concerns were about legitimate threats to survival. Later, their perceptions of certain celestial phenomena and their regularity led to the postulation that they must be controlled and ordered by divinities — and hence to the further false belief that such movements might be suddenly changed, to human disadvantage; Lucr. DRN 5.970–87, 5.1183–93. Nevertheless, as Lucretius is aware that the length of days and nights vary, the early humans too would not have an entirely precise notion of their respective lengths; 5.680–95, cf. Epic. Ep. Pyth. 98. 38 As we have seen above, eventa are real. 39 On seeing the invisible by analogy and deduction, e.g. from the visible, cf. esp. [33]. 40 Epic. Ep. Hdt. 72. On this point, cf. esp. [26] and [25, 210–11]; contra Glidden, cf. [32, 204 n.1]. 41 Regarding the question of the objective or subjective perception of time, cf. e.g. [31, 136 n.18], who comes down on the side of ‘subjective recognition’ and [32, 197–203], who regards time as being equally or indifferently objective and subjective, albeit by agreeing with the thesis of time-atoms. 144 KRITERION – Journal of Philosophy, 2016, 30(2): 125–151

42 [24, 155]. The meanings of these Greek terms are disputed, but all are encompassed by Lucretius’ term. What to others may seem like ambiguity, may have suggested to him underlying connections and conceptual inclusivity. 43 A fuller treatment of sensus in DRN is outside the scope of this study. 44 In support of the claim that the perception of time occurs also with regards to any motion that one can perceive with the mens, cf. PHerc. 1413 fr.84 col.55 and its interpretation by [14, 40]. 45 Lucr. DRN 4.229–30, 6.934–5. 46 Through the vision of the animus we seem to see dancers moving while we sleep, just as one does with the eyes while waking; Lucr. DRN 4.770 and 4.789: ‘in somnis’, 4.791 in [8]: ‘[simulacra] repetunt oculis gestum’, 4.769 and 4.788: ‘in numerum’. We will return shortly to the idea that these are dancers. 47 This takes ‘moveri’ as passive for middle, on the strength of its clear meaning, the parallel with ‘iactare’ in the next line, and the echoes between Lucr. DRN 4.768–9 and 4.788–90, in which the verb is active and transitive: ‘simulacra . . . mollia membra movere’. 48 Here ‘quippe’ relates back to the ‘non est mirum’ of Lucr. DRN 4.768; it also carries the sense that it is introducing the obvious explanation as well as the truth. 49 External stimuli which enter the body in this manner perish, so to speak, by absorption. What happens then is beyond the scope of this investigation. 50 Here ‘simulacra’ (Lucr. DRN 4.768) is taken as the antecedent of ‘prima’ and ‘altera’, such that they are neuter plural subjects with the singular verbs ‘perit’ and ‘est . . . nata’ respectively; if the second point is correct, then Lucretius may be following the model of a Greek construction. Similarly, ‘simulacra’ is also taken as the antecedent of ‘rerum’. It would be more natural to take the adjectives as attracted into the gender and number of ‘imago’ (4.770); regardless, imago seems less likely to be their antecedent for mechanistic reasons which will become clear shortly. 51 Cf. Epic. Ep. Hdt. 47. As [3, iii.1273] notes, Lucretius elsewhere seems to express this idea with ‘puncto tempore’ and the like, as well as other expressions that indicate, in effect, instantaneousness, suddenness, or simultaneity. 52 Contrary to ‘now’ meaning something like ‘today’. On the historical debates about the nature of time and the units by which it can be measured, cf. [40]. Sorabji suggests that Epicurean thought on time was particularly shaped by the reactions of Aristotle and Diodorus Cronus to the paradoxes of Zeno of Elea, but his conclusions about Epicurean time-atoms, as we shall see, do not fit with the evidence for Lucretius’ views on time. On the debates relevant to and including the Epicurean account(s) of time, cf. [40, esp. chs. 1–2, 7, 12, 21–4]. 53 To elaborate: the stimuli would have to be perceived within the now in order for their source-object to be real, according to the past-presentist interpretation, but if the stimuli spent even a moment longer in transmission (as distant and slower moving ones sometimes do) the source-object which generated them would cease to be real. 54 According to Sorabji, only in Diodorus Cronus and not in Epicurus (or, apparently by implication, his followers) do we find the argument that the present is a time- atom; [40, 371]. Pamela Zinn: Lucretius On Time and Its Perception 145

55 The word gestus is often used of an artful gesture, as would seem to fit the movements of the dancers here, but cf. also Lucr. DRN 4.365 and 4.367, where it seems to refer to the larger movement itself — one of the very mundane general sort. In 5.1022 it could refer to either and 5.1031 more likely refers to gesture; in neither of these cases would it be artful, but at least deliberate and purposeful. Cf. gestus, OLD §1, 3. 56 [3, iii.1277] notes that Lucr. DRN 4.799–801 = 4.774, 4.771, 4.772 (except that hoc replaces quippe) but takes this as evidence for a view of the state of the text not unlike that expressed esp. by [12]. The variation makes sense in the context of the respective constructions. 57 The reading ‘quod sentimus’ here follows the text of [3]. Bailey, following Lach- mann, reads this rather than cum sentimus (Munro, Naugerius, etc.) which the edition of Rouse and Smith adopts; each reading claims different parallels in Ep. Hdt. However, according to [3, i.306 and iii.1276–7], OQ and at least some of the Itali read consentimus. Bailey’s reading seems to make the best doctrinal sense of the whole passage, not just by comparison with Epicurus, but also when comparing this passage with Lucr. DRN 4.768–76, especially in light of ‘sensibili quovis . . . tempore in uno’ (4.775) and ‘quovis in tempore’ (4.797). 58 [8, 337 n.b] also use the analogy of how cinematographic pictures function with respect to this process and phenomenon. [3, iii.1273] is dubious of the analogy. 59 According to Lucretius, both the animus and the eyes perceive external source- objects by means of interaction with simulacra and do so according to similar mechanisms; cf. e.g Lucr. DRN 4.749–56. 60 For a different explanation, cf. [38]. 61[3, iii.1274], [12], [13, 121–2 n.4]. 62 Cf. esp. Lucr. DRN 4.732–48, 4.757–67. With the latter, cf. Diog. Oen. fr.9 IV.7–VI.3 Smith. 63 Cf. [3, iii.1277], [13, esp. 107, 109, 120]. 64 Cf. Epic. Ep. Hdt. 62. This instant is perhaps equivalent to Epicurus’ ‘κατὰ τὸν ἐλάχιστον συνεχῆ χρόνον’. 65 The very term atom (ἄτομος) emphasizes the indivisibility of the particles of matter, which Lucretius calls first-beginnings (e.g. primordia), from which all other material bodies are generated. On reasoning from the perceivably indivisible to the imperceivable indivisible, cf. Lucr. DRN 1.746–52; but that is an argument made specifically about corpora and should not be taken to apply to time or space. 66 [14, 30–2], [1, 650], [36, 118–19]. PHerc. 1413 has not been included in the recent critical edition of Epicurus On Nature 2; [6]. 67 Cf. e.g. [14, 42–3] challenging Sextus’ rendering of Epicurus’ ideas on time. 68[48, 368 n.16]. 69 Lucr. DRN 2.80–141, esp. 112–41. 70 Cf. esp. Lucr. DRN 1.265–328, 483–634. 71 [7, i.50–2] are somewhat more sympathetic to the theses against which this paragraph argues with respect to Lucretius. 72 On the side of the time-atom thesis, cf. e.g. [3, iii.1277], [40, 371–7 (esp: 375–7)], [13, 283], [32, 198], [27]. Morel, however, acknowledges that Lucretius does not 146 KRITERION – Journal of Philosophy, 2016, 30(2): 125–151

speak of this. Gœury similarly acknowledges that, with the possible exception of some Herculaneum papyri, Epicurus does not explicitly endorse this thesis and that ‘la notion de durée indivisible risque de suggérer, du point de vue d’Épicure, une substantialisation du temps qui va contre sa caractérisation insistante du temps comme accident’; [27, 552]. Furley similarly expresses tentative agreement with the idea that Epicurean time, space, and motion are only finitely divisible — on the basis of his analysis of Epicurean thought as an answer to Aristotle; [20, e.g. 121] and [21, 103-8]. On the side of infinite divisibility of time, cf. e.g. [18], [15, 478 n.4]. 73 The smallest conceivable measure of time would probably be the time required for a primordium to move a distance equal to its own size through the void; but that measure too would be infinitely divisible without lacking duration. On duration being one of the criteria for motion, cf. [40, 333]. With respect to the issue of succession: the now never actually stops or starts, and there is no boundary in between one perceptible moment and the next. Presumably perceivers could be staggered in the same manner as clocks, so as to show that time itself has no limit of division, even if a given individual’s perception of it does; cf. [40, 367, 383]. 74 Cf. Epic. Ep. Hdt. 62. 75 The term ‘swerve’ thus exaggerates the nature of the movement involved in the clinamen; Lucretius describes it as approximating the slightest inclining which one could call a changed motion (momen mutatum). Cf. Lucr. DRN 2.218–20. 76 Similarly, for Lucretius, the infinity of the void guarantees that the motion of the spear, once thrown and if unobstructed, will continue without end — either spatially or temporally; Lucr. DRN 1.968–83. Compare Lucretius’ lightning bolts and flying spear to Zeno’s paradox of the flying arrow. For Zeno, the infinite divisibility of time leads to an arrow’s lack of motion at any and every conceivable instant; cf. [40, 332–4]. 77 Morel plausibly identifies three modalities of time: time which can be represented by reason alone, perceivable time, and eternity. The first of these, however, he seems to equate with atomic time, which he finds to have at best ‘une unité éminemment friable’, as though it were a succession of time-atoms of the sort towards which Sorabji leans; [32, 205–6]. 78 Lucr. DRN 3.832–42, 3.862–9, 3.972–7, 3.1073–5, 3.1087–94. Cf. Cic. ND 1.21. For discussion, cf. esp. [45], [47, 57–108]. 79 Lucr. DRN 2.142–64, 4.183–216. Cf. Epic. Ep. Hdt. 46–7. This interpretation is in general agreement with that of [13, 107–11]. 80 Lucr. DRN 3.670–8. On this scale it is physically probable that every living creature, as a concilium, has existed and will exist again (with equal claim to reality), albeit with no memory or knowledge of any former lives. Proof of the infinity of matter, e.g. in the analogy of the creation of a ship from wrecks, assumes infinite time and space and motion, cf. 2.547–68. For other implications of the postulation of these infinities by Lucretius, cf. e.g. [29]. 81 Bailey, Asmis, and Morel, for example, also observe this; cf. [3, iii.1273], [13, 120], [32, 198]. On the signification of the word vox, cf. [30]. 82 Lucr. DRN 1.459–63. 83 Lucr. DRN 4.779–87 (N.B. ‘extemplo’, ‘simul ac volumus’, ‘sub verbone’). Pamela Zinn: Lucretius On Time and Its Perception 147

84 The mens cannot move the body at the speed of the perception of time, as one seems to perceive some lapse between voluntas and stirring or curbing of the whole body’s motion; Lucr. DRN 2.263–83. 85 Epic. Ep. Hdt. 48. 86 Epic. Ep. Hdt. 61–2. 87 Lucr. DRN 4.553–71. 88 Lucr. DRN 4.687–705, 6.164–72. Cf. n.59 above. 89 The nearest comparanda, for the simulacra which interact with the eyes, seem to be the speeds at which heat and light travel from the sun to the earth through the air (not through the void, as the heavens are part of the system of the cosmos). Asmis too notes this comparison; [13, 110 n.17]. There is no speed faster than that of the first-beginnings moving through the void, which seems generally both constant and so swift as to be virtually infinite; cf. Lucr. DRN 2.142–64, 4.183–216. 90 Asmis too notes that the relative speeds of simulacra would suggest that (the speed of internal mechanisms being equal) thought should occur faster than vision; [13, 111]. This is not dissimilar from the idea of racing thoughts, or from the idea that in an instant we perceive many things of which we are not consciously aware. The latter has become the basis of a memory retrieval exercise used in forensic science, known as a cognitive interview. 91 This is perhaps further evidence against the thesis of actual minimal units of time. 92 I.e. the cosmos. 93 Here imago seems to refer to each member of a stream of simulacra, taken individually. 94 What are here Lucr. DRN 4.250 and 4.251 were transposed from the reverse order by Marullus; cf. [3, iii.1213]. 95 In this context, ‘is’ is modified by ‘omnis’ and therefore refers to both the air and the simulacra, taken individually; cf. [3, i.374 and iii.1213], contra [8, ad loc.]. The juxtaposition of ‘perterget’ and ‘transit’ suggests at once contact (i.e. collision) and the frictive interaction which occurs during contact with and entrance into the passages of the eyes. The claim that this passage is referring to those processes is perhaps strengthened by the fact that there are a number of verbal echoes with Lucr. DRN 4.714–18, which also concerns simulacra entering eyes: sc. the repetition of ‘acies’ (which in both cases means eyes) and ‘pupillas’, as well as, perhaps, ‘mittitur’/‘inmissa’. Transeo is also used in similar contexts later, at 4.600 and 4.987, where it seems to mean quite clearly ‘to pass through’. Otherwise it may be tempting to take ‘transit’ here in the sense of passing away or ceasing, in the manner of the absorption of food. Given the importance of time and its perception in this passage, one also might wonder whether the choice of ‘geruntur’ here perhaps recalls ‘geruntur’ (1.472) and ‘gerantur’ (1.482). 96 Unless one would posit that two stimuli (of whatever sort(s)) can occupy precisely the same place at exactly the same time. 97 Here the adverb ‘¯un¯a’ seems to be stronger than ‘tempore in uno’ (4.775, 4.794), at least by virtue of expressing the idea in a single word, if not also by obviating the potential ambiguity in tempore of perceivable time. 98 The suddenly severed twitching parts, cf. Lucr. DRN 3.642–69, are still in the process of giving up their equivalent of the metaphorical dying breath. 148 KRITERION – Journal of Philosophy, 2016, 30(2): 125–151

Pamela Zinn Temple University & Villanova University

References

Ancient Sources [1] Arrighetti, G. Epicuro: Opere. Giulio Einaudi: Turin. 2nd edn, 1973. [2] Bailey, C. Epicurus: The Extant Remains. Oxford University Press: Oxford, 1926. [3] Bailey, C. Titi Lucretii Cari: De rerum natura, libri sex. 3 vols. Clarendon Press: Oxford, 1947. repr. Oxford University Press, Oxford, 2001. [4] Brown, P. M. Lucretius: De rerum natura I. Bristol Classical Press: Bristol, 1984. repr. 2001.

[5] Hicks, R. D. Diogenes Laertius: Lives of Eminent Philosophers. Harvard University Press: Cambridge MA, London, 1931. [6] Leone, G. Epicuro: Sulla Natura Libro II. Bibliopolis: Naples, 2012. [7] Long, A. A. and Sedley, D. N. The Hellenistic Philosophers. 2 vols. Cambridge University Press: Cambridge, 1987. [8] Rouse, W. H. D. and Smith, M. F. Lucretius: De rerum natura. Harvard University Press: Cambridge MA, London, 1992. [9] Smith, M. F. Diogenes of Oinoanda: The Epicurean Inscription. Bibliopolis: Naples, 1993. [10] Usener, H. Epicurea. B. G. Teubner: Leipzig, 1877. Pamela Zinn: Lucretius On Time and Its Perception 149

Secondary Sources [11] Annas, J. E. Hellenistic Philosophy of Mind. University of Califor- nia Press: Berkeley CA, Los Angeles CA, London, 1992.

[12] Asmis, E. “Lucretius’ Explanation of Moving Dream Figures at 4.768–76”. In: The American Journal of Philology 102.2 (1981), pp. 138–45.

[13] Asmis, E. Epicurus’ Scientific Method. Cornell University Press: Ithaca NY, London, 1984.

[14] Barigazzi, A. “Il concetto del tempo nella fisica atomistica”. In: Epicurea: In memoriam Hectoris Bignone. Istituto di filologia classica: Genova, 1959, pp. 29–60.

[15] Berns, G. “Time and Nature in Lucretius’ De rerum natura”. In: Hermes 104.4 (1976), pp. 477–92.

[16] Bollack, J. and M. 1983. “Temps, comme devenir (Lucrèce I 464–482)”. In: Συζήτησις 1983, pp. 309–27. [17] Campbell, G. L. “Oracular Cosmology in Lucretius”. In: Cosmolo- gies et cosmogonies dans la littérature antique. Ed by P. Derron, T. Fuhrer, and M. Erler. 2015, pp. 149–71.

[18] Caujolle-Zaslawsky, F. “Le temps épicurien est-il atomique?”. In: Les Études philosophiques 3 (1980), pp. 285–306.

[19] Derron, P., Fuhrer, T., Erler, M. (eds) Cosmologies et cosmogo- nies dans la littérature antique. Fondation Hardt Entretiens sur l’antiquité classique 61: Geneva, 2015.

[20] Furley, D. J. Two Studies in the Greek Atomists. Princeton Uni- versity Press: Princeton NJ, 1967.

[21] Furley, D. J. “Aristotle and the Atomists on Infinity”. In Cosmic Problems. D. J. Furley. Cambridge University Press: Cambridge, 1989, pp. 77–90. repr. from Naturphilosophie bei Aristoteles und Theophrast: Proceedings of the Fourth Symposium Aristotelicum. Ed. by I. Düring. Lothar Stiehm Verlag: Heidelberg, 1969, pp. 85–96.

[22] Gale, M. R. (ed.) Oxford Readings in Classical Studies: Lucretius. Oxford University Press: Oxford, 2007. 150 KRITERION – Journal of Philosophy, 2016, 30(2): 125–151

[23] Gignon, O. (ed.) Lucrèce. Fondation Hardt Entretiens sur l’antiquité classique 24: Geneva, 1978. [24] Glidden, D. K. “Sensus and Sense Perception in the De rerum natura”. In: California Studies in Classical Antiquity 12 (1979), pp. 155–81. [25] Glidden, D. K. “Epicurean Prolepsis”. In: Oxford Studies in Ancient Philosophy 3 (1985), pp. 175–217. [26] Gœury, M. “L’absence de préconception du temps chez Épicure: Lecture de la Lettre à Hérodote, 72–73”. In: Philosophie antique 12 (2012), pp. 89–114. [27] Gœury, M. “L’ atomisme épicurien du temps à la lumière de la Physique d’Aristote”. In: Les Études philosophiques 107 (2013), pp. 535–552. [28] Lehoux, D., Morrison, A. D., and Sharrock, A. (eds.) Lucretius: Poetry, Philosophy, Science. Oxford University Press: Oxford, 2013. [29] Kennedy, D. F. “The Political Epistemology of Infinity”. In: Lu- cretius: Poetry, Philosophy, Science. Ed. by D. Lehoux, A. D. Morrison, and A. Sharrock. 2013, pp. 51–67. [30] Koenen, M. H. “Lucretius’ Explanation of Hearing in De rerum natura IV. 524-562”. In: Mnemosyne 52.4 (1999), pp. 434-463. [31] Konstan, D. A Life Worthy of the Gods: The Materialist Psychol- ogy of Epicurus. Parmenides Publishing: Las Vegas NV, Zurich, Athens, 2008. [32] Morel, P.-M. “Les ambiguïtés de la conception épicurienne du temps”. In: Revue philosophique de la France et de l’étranger 127.2 (2002), pp. 195–211. [33] Schrijvers, P. H. “Seeing the Invisible: A Study of Lucretius’ Use of Analogy in the De rerum natura”, trans. M. R. Gale. In: Oxford Readings in Classical Studies: Lucretius. Ed. by M. R. Gale. 2007, pp. 255–88. repr. from ‘Le regard sur l’invisible: étude sur l’emploi de l’analogie dans l’œvere de Lucrèce’, In: Lucrèce. Ed by O. Gignon. 1978, pp. 77–114.

[34] Sedley, D. N. “Epicurus’ Refutation of Determinism”. In: Συζήτησις 1983, pp. 11-51. Pamela Zinn: Lucretius On Time and Its Perception 151

[35] Sedley, D. N. “Epicurean Anti-Reductionism”. In: Matter and Metaphysics: Fourth Symposium Hellenisticum. Ed. by J. Barnes and M. Mignucci. Bibliopolis: Naples. 1988, pp. 297–327. [36] Sedley, D. N. Lucretius and the Transformation of Greek Wisdom. Cambridge University Press: Cambridge, 1998. [37] Segal, C. Lucretius on Death and Anxiety: Poetry and Philosophy in De rerum natura. Princeton University Press: Princeton, 1990. [38] Sharples, R. W. “Some Problems in Lucretius’ Account of Vision”. In: Leeds International Classical Studies 1.2 (2002), pp. 1–11. [39] Solmsen, F. “αἴσθησις in Aristotelian and Epicurean thought”, In: Probleme der Lukrezforschung. Ed. by C. J. Classen. G. Olms: Hildesheim, Zurich, New York. 1986, pp. 151–72. repr. from Med- edelingen der Koninklijke Nederlandse Akademie van Wetenschap- pen, AFD Letterkunde, Nieuwe Reeks 24 (1961), pp. 612-33. [40] Sorabji, R. Time, Creation and the Continuum. Duckworth: Lon- don, 1983. [41] Συζήτησις: Studi sull’ epicureismo greco e romano offerti a M. Gigante. 2 vols. Gaetano Macchiaroli: Naples, 1983. [42] Striker, G. “Epicurus on the Truth of Sense Impressions”, In: Archiv für Geschichte der Philosophie 59 (1977), pp. 125–42. [43] Verde, F. “Rebus ab ipsis consequitur sensus: Il tempo in Epicuro”. In: Elenchos 29.1 (2008), pp. 91–117. [44] Wardy, R. “Lucretius on What Atoms Are Not”, In: Classical Philology 83.2 (1988), pp. 112–28. [45] Warren, J. “Lucretius, Symmetry Arguments, and Fearing Death”, In: Phronesis 46.4 (2001), pp. 466–91. [46] Warren, J. Epicurus and Democritean Ethics: An Archaeology of Ataraxia. Cambridge University Press: Cambridge, 2002. [47] Warren, J. Facing Death: Epicurus and His Critics. Oxford Uni- versity Press: Oxford, 2004. [48] Warren, J. “Epicureans and the Present Past”, In: Phronesis 51.4 (2006), pp. 362–87.