Truthmaking Is Not Necessitation
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Truthmaking is not necessitation Philipp Keller∗ 3rd October 2005 Comments and criticism very welcome Abstract I argue against truthmaker necessitarianism, the view that truthmaking is necessitation. I argue !rst that David Armstrong"s argument for it is ill#motivated and establishes only a weaker thesis $ truthmaker internalism $, that truthmaking is an internal relation in David Lewis" sense. I then argue that necessitation is not su%cient for truthmaking. The argument for its non#necessity examines !rst Armstrong"s particular version of necessitarianism, truthmaking by states of a&airs. Some of the relevant considerations are then generalised in order to make the broader claim plausible. How is it that by !xing our gaze on 'there are no artic penguins( we may learn something about the animal life of some distant geographical region? A popular answer has it that the question divides into two subquestions: how do we understand the truth expressed by these marks? and: what makes this truth true? While these two questions are obviously related, I will concentrate on the second in the following. The truthmaker question has of course much wider application than to penguins. In particular, it may be asked to determine the entities and categories of entities in the existence of which someone believes. This is of particular use in metaphysics, and I therefore agree with Armstrong that asking the truthmaker question is a promising way to regiment metaphysical enquiry )Armstrong 2004a: 4*. In particular, I agree with him that 'continually to raise the truthmaker question about properties makes for ontological honesty( )Armstrong 2004a: 43*. I also think that answering the truthmaker question commits us to an ontology of sparse properties,'in terms of which the worl+s work is done( )Armstrong 2004a: 17*, and that this is motivated by the fact that, intuitively speaking, we do not need the whole of the particular to make non#relational predications true )Armstrong 2004a: 41*. I also agree with Armstrong that we should start o& as truthmaker maximalists, i.e. only give up on our search for truthmakers once its futility in some particular case has been demonstrated. My argument against necessitarianism presupposes that we are after a uniform account of truth as being made true. The regimentation metaphysical enquiry will receive from asking and answering truthmaking ques# tions will of course depend on what the truthmaking relation is taken to be. It is commonly assumed that truthmaking is necessitation and this is the thesis I will criticize in the following: 1 !Truthmaker Necessitarianism". The determining of a truth by a truthmaker is an absolute ne! cessitation. Truthmaker necessitarianism is one of Armstrong"s reasons for believing in states of a&airs. Because the truthmaker for the contingently true predication 'F a( must necessitate its truth, it cannot be F ∗University of Geneva, Switzerland, [email protected]. 1 or a alone, nor their fusion, for all the three of them could exist without 'F a("s being true. Hence it is the state of a&airs a"s being F )cf. Armstrong )1989b: 88* and also Armstrong )1997: 115**: 'If it is said that the truthmaker for a truth could have failed to make the truth true, then we will surely think that the alleged truthmaker was insu%cient by itself and requires to be supplemented in some way. A contingently su%cient truthmaker will be true only i" circumstances that obtain in this world. But then these circumstances, whatever they are, must be added to give the full truthmaker.( )Armstrong 1997: 116* While there are other arguments for truthmaker necessitarianism, it is this ,su%ciency argumen- that provides the strongest motivation for believing that truthmaking is necessitation. The su%ciency argument, as Armstrong )1997: 115* says, establishes that the truthmaking relation is internal. This brings out a viable intuition: the truthmaking relation cannot depend on facts about things outside the items it relates. If T makes it true that p, nothing else than T and p have a bearing on whether or not the truthmaking relation holds between them. If the truthmaking would depend on something outside T and p, this additional circumstance would have to be brought into T , as Armstrong says. Another, equally good reason to take the truthmaking relation to be internal is the following: external, but not internal relations are ontological additions to their terms. If truthmaking was an external relation, it would be an addition to the 'ontology of the situation( )Armstrong 2004a: 9* $ it itself would have to be brought into the truthmaker, creating an in!nite regress. So the su%ciency argument establishes the following: 2 !Truthmaker internalism". Truthmaking is an internal relation. Whether we get truthmaker necessitarianism out of truthmaker internalism, of course, depends on what we mean by 'internal(. 'Internal relation(, however, is a notoriously ambiguous term.1 Bradley )1893: 392* used it to character# ise relations that 'essentially penetrate .…/ the being of .their/ terms(, Moore )1919$1920* for relations that supervene on monadic foundations which are 'critical to the identity of the terms to which they belong( and Wittgenstein in the Tractatus for relations the relata of which are inconceivable without them )Wittgenstein 1921: §4.123*. What does Armstrong mean by an 'internal relation(? Armstrong )1978b: 85* de!ned an internal relation as follows: Two or more particulars are internally related if and only if there exist properties of the particulars which logically necessitate that the relation holds. They are externally related if and only if there are no properties which necessitate the relation or a part of it. The properties in question here must be understood as intrinsic properties. So we get the following account: De#nition 3 !Internal relations". A relation is internal i# it supervenes on the intrinsic properties of its relata.2 Armstrong, however, also characterises internal relations in some, at least prima faci$, di&erent way: 'I mean by calling a relation internal that, given just the terms of the relation, the relation between them is necessitated.( )Armstrong 2004a: 9* 1Ewing )1934* identi!es ten senses of 'internal relation(. 2Lewis )1986: 62* calls an internal relation 'intrinsic to its relata( )cf. also Lewis 1983: 26, n. 16*. 2 This turns truthmaker internalism into truthmaker necessitarianism. How is such a transition to be justi!ed? Armstrong )1997: 12, 87, 115* says that a relation is internal if and only if it is impossible that its terms should exist and the relation not exist, where the joint existence of the terms is possible. He then adds that 'to fall under our de!nition of internal relations, the particulars involved must be taken as having their non#relational properties( )Armstrong 1997: 88*. This means that the terms necessitating the internal relations are to be thought of as the 'thick particulars(, the particulars ,taken together" with their intrinsic properties.3 The thesis that truthmaking is internal in the sense of supervening on intrinsic properties of truth# maker and truthbearer is prima faci$ di&erent from truthmaker necessitarianism because it can be reasonably questioned whether all intrinsic properties are 'given just the terms of the relation(. It may well be that some intrinsic properties of some truthmaker are not essential to it, i.e. such that the truthmaker could exist without exemplifying them. This, I think, is reason enough to distinguish truthmaker internalism from truthmaker necessitarianism. Truthmaker internalism )2* brings out the sense of su%ciency we are after in our quest for truthmakers, for it means that it is a matter of how a thing is itself what truthbearers it makes true. We only have chosen our truthmaker inclusive enough if its truthmaking ties do not depend on anything ,outside" of it, i.e. if they cannot be made to vary by variation in the intrinsic properties of things disjoint of our truthmaker in question. Such a relation, however, can still be contingent. It is one thing to say that the truthmakers for the obtaining of an internal relation are just the terms of the relation )Armstrong 2004a: 92,98,104,139* and that internal relations are ontologically innocent )Armstrong 2004a: 104*. It is another thing to take this to entail necessitarianism. Even though the su%ciency argument does not privilege truthmaker necessitarianism over truthmaker internalism, the former may be held to be independently plausible. How could something, it may simply be asked, be su%cient for the truth that p even if it could exist without p being true? I think, however, that necessitation is neither necessary nor su%cient for truthmaking. 1 Necessitation is not su$cient for truthmaking Let me start with the non#su%ciency claim. This is the easier part of the argument, as many of the relevant points have already been made. I will call, following Smith )1999*, entities that necessitate truths they do not make true ,malignant necessitators". There are at least three areas where malig# nant necessitators may be found: truthmakers for necessary truths, extrinsic essential properties and necessary but accidential properties. With respect to logical truths, Restall )1996* pointed out that if T makes it true that p and if the truthmaker of a disjunction makes at least one disjunct true, then T makes every proposition true, which 'gives logic a certain grandeur( )Restall 1996: 333, n. 3*. He proposed to spell out the entailment from the existence of a truthmaker to the truth of the proposition as a kind of relevant implication that does not support disjunction introduction. In order not to trivialise truthmaking, we also have to restrict transmission of truthmaking over entailments to those that involve only contingent truths. Such a restriction, even if combined with a relevantist account of necessitation, does not solve the problems in this area.