On Laws and Ends: A Response to Hattab and Menn

Dennis Des Chene Johns Hopkins University

From the topics discussed by Hattab and Menn, I examine two of special im- portance. The ªrst is that of active powers: does the Cartesian natural world contain any, or is the apparent efªcacy of natural agents always to be re- ferred to God? In arguing that it is, I consider, following Hattab, Descartes’ characterization of natural laws as “secondary causes.” The second topic is that of ends. Menn argues, and I agree, that in late Aristotelianism Aris- totle’s own conception of an “art in things” has been abandoned. The point is reinforced when one considers the general divine ends which must be in- voked in cases of aborted action. In them no individual agent attains its end. Yet Nature as a whole continues to act toward ends. I suggest that those general ends, to which Suárez, for example, refers, may have served later philosophers, especially Malebranche, in combining the Cartesian notion of law with a teleological interpretation of nature that Descartes, for his part, rejected. In the transition from Aristotelian natural philosophy—more speciªcally, that version which Menn calls “liberal Jesuit Scholasticism”—to the mechanistic philosophy of the new science, two questions are of funda- mental importance in the explanation of natural events and our relation to them as knowing subjects and as agents. The ªrst is that of agency, the second that of the laws of nature. The Aristotelian philosophy takes natu- ral change to be the work of active powers in nature itself, in which God concurs. The Cartesian interprets it as the work of God alone, subject to natural laws, appeal to which will help demonstrate the observed regulari- ties which by the Aristotelian are referred to the intrinsic powers of mate- rial things, and to the ends toward which they act. By the question of agency, then, I mean in particular the question ‘Where are the active powers that bring about change in the natural

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Downloaded from http://www.mitpressjournals.org/doi/pdf/10.1162/106361400568055 by guest on 26 September 2021 Perspectives on Science 145 world?’ Hattab’s paper, after discussing Descartes’ conception of force, de- votes itself to arguing that when he calls the laws of nature “secondary causes,” he should be taken at his word. It then explains how laws can be regarded as causes at all, and how they might occupy the role which in late Aristotelian physics was occupied by the active powers of natural agents. I remain, nevertheless, puzzled both by Descartes’ terminology and by the notion of laws as causes, and I will show why. The question of ends is yet simpler: Are there any? Or, more pointedly: Are there any ends other than those intended by rational agents? Certainly we conceive of some of our actions as directed to an end. We conceive of God likewise as having acted, in establishing the constitution of the natu- ral and human worlds, and in those particular interventions recorded in texts held true by faith, to accomplish various ends. In Physiologia I argued that for the Aristotelian philosophers I was concerned with, Aristotle’s own conception of ends as intrinsic to natural agents had become increas- ingly opaque. Another conception—that the ends of natural agents are in- tended by God—had largely usurped its place. Adopting that conception, however, gave urgency to the problem of retaining for natural agents any genuine efªcacy. If art is no longer in things, but only in divine or human intellects, then natural agents seem to be reduced to instruments. That outcome, though welcomed by Descartes, was rejected by the Aristo- telians. On this, I think, Menn and I agree. We disagree on the interpreta- tion of Suárez’s position, so I will do my best to clarify matters.1

1. Where is agency? The ªrst topic, then, is agency and active powers. For Aristotelians, in every natural change, there is an agent and a patient. The difference is real: it does not depend on our conception. Just as real are the powers by which agents act. The efªcient cause of a natural change is an agent designated from the point of view of the effect it produces in the patient, to which it

1. Since I have mentioned Aristotelianism several times, I will now exercise the au- thor’s privilege of retrospective revision. I should have emphasized more than I did in Physiologia that the Aristotelians in question are those that Menn calls ‘liberal Jesuit Scho- lastics.’ Generalizations about Aristotelianism, even in the relatively brief period I exam- ined, must be either very broadly stated or limited in scope. Even among those who adopted Thomas Aquinas as their patron, there are major differences of opinion; the differ- ences grow all the greater if one takes in Scotists, Nominalists, or mavericks like Zabarella. Combining ideas from Ed Grant and Dan Sperber, I would take ‘Aristotelianism’ to denote neither an essence nor a natural kind, but a massive and heterogeneous collection of con- cepts, methods, and doctrines endemic to the learned world of the period, which may be likened to a biological population (Grant 1987). Like inºuenza and other successful patho- gens it was easily transmissible and amenable to variation, and therefore capable of surviv- ing in diverse environment (Sperber 1996).

Downloaded from http://www.mitpressjournals.org/doi/pdf/10.1162/106361400568055 by guest on 26 September 2021 146 Laws and Ends gives, as all causes do, being. It brings into existence a quality like heat or even introduces a new substantial form into pre-existing matter. Unlike the material or formal causes the efªcient cause is extrinsic to its effect, even if per accidens cause and effect are identical individuals. That is far from the whole story, but it will do for now. The question at hand is: where is agency? In particular, do secondary causes have any efªcacy of their own, or are they instead like a carpenter’s saw, modulating the effects of the First Cause, but not themselves even the proximate principle of any action? It is agreed that God not only creates and conserves all other beings, but must allow, indeed co-operate with, their actions. Can a natural, nonrational, agent nevertheless be—I quote here Suárez’s version of the deªnition—“the ªrst principle from which there is an action,” or again “from which the effect exists, by way of an ac- tion” (Disp. 17§1¶6; Suárez [1856] 1965, 25:582)? Descartes’ answer is No. That natural agents have no active powers whatsoever follows immediately from the deªnition of ‘corporeal sub- stance’ or ‘body’ as res extensa. If there are efªcient causes acting in nature other than God, they cannot be bodies. Descartes says that laws are causes, but ªrst one other candidate must be considered: force. Hattab has given a clear summary of the section in Physiologia where I sort out the interpreta- tions of Hatªeld, Gueroult, Gabbey, and Garber. From that discussion I arrive at what she calls a “double-aspect” interpretation of force. There is no one thing of which one can say both that it is a mover of bodies, an ac- tive power, and that it is measured by the quantity volume times speed. Volume and speed, and derivatively the product of the two, pertain to bodies; activity to God. In the case where a body at rest successfully resists a moving body—as in Descartes’ fourth rule of collision—the natural inertia possessed by every body, at rest or not, does not yield a “force of resistance” sufªcient to explain the outcome. The moving body can have any speed whatever; yet the body at rest, provided only that it is larger, will not budge. The usual factor measuring the conversion of the moving body’s quantity of motion into a quantity of motion in the body at rest, namely the ratio of the mov- ing body’s volume to that of the resting body, will not yield what Des- cartes wants. Instead the body at rest behaves as if it were part of some more inclusive body, as large as need be to compel the moving body to re- verse its course. From the standpoint of the smaller moving body, the force opposing its continued motion is effectively inªnite. In trying to grasp what Descartes had in mind in formulating the rules of collision, and considering the references to divine action in his argu- ments for the laws of nature, I suggested that we should think of the mov- ing force attributed to God as consisting in his concurrence, governed by

Downloaded from http://www.mitpressjournals.org/doi/pdf/10.1162/106361400568055 by guest on 26 September 2021 Perspectives on Science 147 those laws, in the changes that occur when bodies meet; but that the indeªnitely large force of resistance exhibited by some bodies at rest would be better referred to conservation. Hattab raises two questions. The ªrst concerns the parallel between “static” forces and conservation. I made two comparisons of this sort. One comparison, deriving ultimately from Bonaventura, is between conserva- tion and the force exerted by a nail, say, when it holds up a picture. This was by way of trying to understand how (as Gueroult believes) conserva- tion could be thought of as a force at all (Gueroult [1954] 1970). The other I’ve just mentioned. Moving force is measured by volume times speed. But force of resistance, which as the force of a body at rest is in a sense “static,” is effectively inªnite. So perhaps that force could be referred to conservation. I hoped thereby partially to vindicate Gueroult’s under- standing of force. In doing so, I presupposed that for Descartes concurrence and conserva- tion are distinct. Otherwise it would do no good to refer moving force to one and force of resistance to the other. Descartes does use both terms. But I am inclined to agree with Hattab that he makes no steady distinction between them. Consulting the statement of the laws of nature in Monde, for example, one ªnds reference only to conservation. In a letter of 1641 to the so-called Hyperaspistes, on the other hand, Descartes takes the conser- vation of created substances to be an instance of concurrence. I quoted that letter in the very pages Hattab refers to. But I did not think through its consequences for the argument I made shortly thereafter. In the letter Des- cartes treats created substance as if its own existence were among its ef- fects; but since only God is truly causa sui, his concurrence in that self- action is required if it is to succeed. The Principia retain the term concursus in the deªnition of substance,2 while in the section introducing the laws of nature Descartes writes that God conserves quantity of motion by “his or- dinary concurrence alone.”3 Conserving that quantity would seem to be a special case of concurrence, and not a distinct kind of action. The main result, however,—the “double-aspect” theory of force—re- mains, I think, untouched. Quantity of motion, measured by the product

2. “Per substantiam nihil aluid intelligere possumus, quàm rem quæ ita existit, ut nullâ aliâ re indigeat ad existendum. Et quidem substantia quæ nullâ planè re indigeat, unica tantúm potest intelligi, nempe Deus. Alias verò omnes, non nisi ope concursùs Dei existere posse percipimus” (Principles 1§61, AT 8/1:24). Note: All references to Descartes are to the Adam-Tannery edition (Descartes 1964). 3. “Et generalem quod attinet, manifestum mihi videtur illam non aliam esse, quàm Deum ipsum, qui materiam simul cum motu & quiete in principio creavit, jamque, per solum suum concursum ordinarium, tantundem motús & quietis in eâ totâ quantum tunc posuit conservat” (Principles 2§36; AT 8/1:61).

Downloaded from http://www.mitpressjournals.org/doi/pdf/10.1162/106361400568055 by guest on 26 September 2021 148 Laws and Ends of volume and speed, exists, if anywhere, in bodies. Using it, we could, if the bodies in question existed in vacuo, predict what happens in collisions. The quantitative laws of motion can be stated and applied without refer- ence to any cause of motion. Like the sine law derived by Descartes in the Dioptrique, they can be regarded as merely phenomenological. But physics cannot, in Descartes’ view, content itself with pheno- menological laws. It must assert a principle of motion. For Descartes this is the unchanging efªcient-causal relation of God to the world established in the act of creation and continued thereafter. The ground of that relation in God is his power, which appears to the naïve or the Aristotelian mind as a force residing in bodies themselves. But it does not. It appears also to vary, because its effects—the speeds and directions of moving bod- ies—vary. But that variation is an illusion; the illusion arises from consid- ering only a part of the terminus of God’s action, namely the colliding bodies, and not the whole, which is the created material world. If we con- sider the whole, then we see that God’s action does not vary, nor does its effect—the total quantity of motion in the world. The quantity of motion in an individual body does not measure the intensity of God’s action, nor of the application of his power to that body or to others. It merely deter- mines what changes will occur.

2. Laws ofnature If concurrence is the more fundamental of God’s actions on created things, then the question Hattab raises next is all the more urgent. God concurs in the action of efªcient causes. But if no body is an efªcient cause, with whose action does God concur? Ours, no doubt; but sticks and stones have no soul, hence no will with whose action God might concur. Hattab’s pro- posal is that when Descartes speaks of the laws of nature as secondary causes, he should be taken at his word. Those laws, then, are analogous to the forms with whose action God is said by Aristotelian philosophers to concur. The basis of the analogy is this. When God concurs with ªre, say, in heating a stone or with water in cooling it, his action would seem to vary. But that cannot be because God himself varies—as if he were hot one mo- ment and cold the next. So the variation must be ascribed to something else. In a world with active powers, there are two candidates: those powers themselves, and the objects on which they act. Jointly the power and the object specify the action; God’s concurrence consists in his determining the act in number. So too in Descartes’ world, God’s action cannot vary. “We understand,” Descartes says, “that perfection in God consists not only in his being im- mutable in himself, but also in his operating in as constant and immuta-

Downloaded from http://www.mitpressjournals.org/doi/pdf/10.1162/106361400568055 by guest on 26 September 2021 Perspectives on Science 149 ble a way as possible” (Principles 2§36). A perfect being is immutable not only in what it is, but in what it does. The occurrence of change, therefore, cannot be ascribed either to any alteration in God, nor to any alteration in the exercise of his power. In Descartes’ world, unlike the Aristotelian, there are no active powers; speciªc variation in effects cannot be ascribed to speciªc differences among powers. Instead Descartes appeals to laws. In any interaction among bodies, those laws, together with the speed and volume of the bodies in question, “determine the speciªc rate and direc- tion of each individual action,” as Hattab says. Speeds and volumes alone determine nothing. Nor does the conserva- tion of the total quantity of motion in the world. Let us suppose that an “occasionalist” interpretation of Descartes’ treatment of force, as Hattab calls it, is correct. When one body moves so as to create a situation in which it could not keep moving in the same way without impinging upon another, the ªrst law yields a conºict. The two bodies cannot remain in the state they were in, on pain of coinciding in all or part of their exten- sion. That, as Descartes tries to explain to More, is impossible. But the conºict could be resolved in any number of ways. All we have inferred so far from God’s immutability is that the quantity of motion in the total ob- ject of his creative act must remain constant. But there is no reason why, if the efªcient cause of all motion is God, he should not resolve the conºict in a way that to us would look like action at a distance—why bodies in motion and about to collide should not be brought to a standstill, and their motion redistributed to others. Hattab, in arguing that the laws of nature do not follow from God’s immutability alone, holds that they depend also on the existence of a ma- terial world. That the laws are laws of a world of res extensæ has, no doubt, a role in determining their character. It is clear, for example, that the very possibility of collision presupposes that bodies are extended. But is it sufªcient? Of the three laws, the ªrst is the most promising.4 But even here, two considerations need to be brought forward. The ªrst is that God

4. The ªrst law is that “each thing, insofar as it is simple and indivisible, remains, as much as it lies within it to do so [quantum in se est; in the French, autant qu’il se peut], in the same state always, nor does it ever change unless by external causes” (Principles 2§37; AT 8/1:62). The second law is that “each part of matter, taken by itself [seorsim spectatam, corre- sponding to the quantum in se est of the ªrst law], never tends to move along any oblique line, but only along straight lines” (ibid. §39, 8/1:63). The third law, the only law concern- ing the interaction of bodies, is that “when a moving body encounters another, if it has less force [vim] to persist along a straight line, than the other has to resist it, then it is deºected in the other direction, and, retaining its motion, gives up only the determination of its motion; if it has more [force], then it moves the other body with it, and gives it as much of its motion, as it loses” (ibid. §40, 8/1:65). It is the second part of the third law that Des- cartes derives from the immutability of the divine operation of conservation: “conserving

Downloaded from http://www.mitpressjournals.org/doi/pdf/10.1162/106361400568055 by guest on 26 September 2021 150 Laws and Ends operates in “as constant and immutable a way as possible”: with emphasis on the quàm maximè (modo quàm maximè constanti & immutabili operetur). The second is to apply the ªrst consideration not merely to God’s total action of conservation, or to that action through time, but to the partial acts of conservation whose termini are the parts of matter. Only then can we infer that this individual will remain in the same state. Hence, perhaps, the phrase quantum in se est: we are considering this individual, this part of matter, as if it alone had been created by God. Descartes’ ªrst law, however, applies to motion merely as one among many modes that constitute a body’s state. Only the next two laws concern motion in particular. In the second law, it is not the individual body that we are to consider as the object of God’s conserving act, but its motion “precisely as it is in the very moment in which he conserves it” (2§39). That is clear enough. But in the argument for the third law, after observ- ing that there are situations in which, on pain of interpenetration, a col- lection of bodies cannot individually each satisfy the ªrst two laws, Des- cartes says only that

conserving it [the world] with the same action, and with the same laws as those he created it with, he conserves motion, not ªxed al- ways in the same parts of matter, but passing from some to others insofar as they run into one another (2§42).

True enough: but again nothing follows about the distribution of motion resulting from the conºict. What one must designate here as the partial object of God’s action—by analogy with the ªrst two laws—is, in the sim- plest case of a two-body interaction, the total quantity of motion in those two bodies. (We could, at the moment of impact, regard them as one; but if they separate after impact, we still need to know which gets how much speed when they are two again.) There is no surprise in all this. The pre- sumption is simply that there is no actio in distans: God redistributes mo- tion from one body to another only when they touch. But this follows nei- ther from immutability nor, so far as I can see, from the nature of body. Perhaps it is, in some sense, the simplest basis for redistribution, and could therefore be derived as Descartes attempts to derive rectilinear mo- tion in the second law; Descartes, however, seems not to have noticed that a derivation was needed. My point is not so much that divine immutability and the nature of matter yield no determinate manner in which to redistribute motion, as motion by the same action, and with the same laws with which he created [the world],” God transfers motion from one body to another as needed when collisions occur, so as to preserve the same quantity of motion eternally.

Downloaded from http://www.mitpressjournals.org/doi/pdf/10.1162/106361400568055 by guest on 26 September 2021 Perspectives on Science 151 that the application of the immutability of God’s operation to the task of deriving laws of nature simply breaks down in the third law, for lack of a partial object to determine a partial action that one could then regard as immutable in its own right. In the ªrst law, and even in the second, there is such an object. But not in the third. This observation tells against the claim that the laws of nature arise “si- multaneously from the existence of matter and God’s decision to act on it”—or from those alone, at least. But it only goes to strengthen Hattab’s claim that the operation of the laws of nature “need not be regarded as an indistinguishable aspect of God’s causal action.” For now, in addition to the decision (so to speak) that there should be a world of res extensæ, and that it should be endowed with a certain total quantity of motion, and all the little decisions to give one particle one part of the total, and another another, there are further decisions: that there should be no appearance of action at a distance, for example. The question remains whether the laws of nature, as Descartes con- ceives them, can be treated as efªcient causes. At the end of her paper, Hattab writes, “These constraints [i.e., those arising from God’s decision to create extended stuff and act on it] make the divine action determinate and that determinate action causes the modes of matter.” I agree that the constraints, if indeed they are constraints, do not arise from the nature God attributes to matter or from immutability alone or jointly. But it re- mains unclear to me how constraints, even if they are independent of God’s action and so forth, can be causes. It does not worry me that they might be continuous with God’s action, or that they are not substances. There I think Hattab is on ªrm ground. The problem is rather with the word ‘constraint’ itself. Nothing can truly hinder God, especially Des- cartes’ God, from carrying out his volitions. So constraints cannot be, as it were, powers compelling God to do some things and not others. If they are causes they must be, to use the phrase Menn takes from Suárez and Fonseca, “essentially subordinated” to the First Cause. I think, moreover, that Descartes, in attempting to derive the laws from the immutability of God’s will, wants thereby to avoid any sugges- tion that God is in fact constrained. Immutability is, like the steadfastness Descartes recommends in his morale provisoire, a purely formal character of volitions. In God’s case, I don’t think the steadfastness of his will can be regarded as a decision by God to bind himself by his own decisions. It is simply a consequence of his perfection. Like inªniteness, it is, despite the etymology, a positive character; the mutability of our wills is, like the ªniteness of our intellects, a lack. One might think, however, that once having willed that there should be a material world, God is constrained, so to speak, in the further speciªcation of his volition. I tend to agree with

Downloaded from http://www.mitpressjournals.org/doi/pdf/10.1162/106361400568055 by guest on 26 September 2021 152 Laws and Ends Hattab that he is indeed constrained. But it is worth noting that even in the third law, Descartes does his best to produce a derivation from immu- tability conjoined with the impossibility, even for God, of making two numerically distinct bodies overlap, an impossibility of the same stripe as that of creating a void. Even if he failed, that is what he intended. How then might laws nevertheless be causes? In one of the passages cited by Hattab, Descartes uses the interesting word efªcacitas—“ut naturæ legum efªcacitatem in propositâ hypothesi ostendere incipiamus” (“in order that we may begin to exhibit the efªcacy of the laws of nature in the proposed hypothesis”) about the initial state of the universe (Principles 3§48). The word efªcacitas was often used of laws. We still use ‘effective’ or ‘in effect’ in a like sense. In present-day uses of the term ‘law’ both in sci- ence and in the legal system, laws are generally regarded as linguistic enti- ties or as expressing propositions. People and things obey or enforce them, but laws themselves cannot be efªcient causes. In the seventeenth century, on the other hand, a law could be regarded as a particular will of the sover- eign. Malebranche, in the chapter of the Recherche cited by Hattab, speaks of God’s particular volitions as “efªcacious.” The laws of nature, it would seem, are volitions, hence eligible if anything is to be efªcient causes. Descartes avoids the legislative analogy. Neither in Monde nor in the Principia is it suggested, except of course by the words loi and lex them- selves. Instead he consistently treats the laws of nature as consequences of immutability. It is as if the only volitions Descartes thought he needed were the volition to create a world and give it motion, acts one could think of as entirely free. In the Principia both the “universal and primary” cause of motion—namely, the conservation of the total quantity of motion God imparted to matter at its creation—and the “secondary and particu- lar” causes—the laws of nature—are said to follow from his immutability. So the thought that laws might be particular volitions, and therefore causes, seems to run aground. There are, it would seem, no particular voli- tions whose content is that these laws should hold. What are we left with? The universal and primary cause of change ex- plains why there is change at all; the particular and secondary causes ex- plain why, in such-and-such a situation, such-and-such a change occurs. That is how the phrase ‘secondary cause’ enters the text. Among Descartes’ predecessors, universal causes are celestial agencies which assist particular mundane causes in generation and corruption. They are universal because they act everywhere and at all times, whereas mundane causes—animal souls, for example—have a very limited sphere of inºuence and act only from time to time. Descartes, having no use for that contrast, takes as his universal cause the conservation of the total quantity of motion in the

Downloaded from http://www.mitpressjournals.org/doi/pdf/10.1162/106361400568055 by guest on 26 September 2021 Perspectives on Science 153 world—which is to say, immutability as it applies to the total object of creation. His particular causes consist in the consequences of immutability for the partial objects of that act—individual bodies or collections thereof. We might suspect, then, that having diverted ‘universal’ and ‘particu- lar’ to a sense quite different from the Aristotelian, Descartes might well be doing the same with primarius and secondarius. Unlike prima and secunda, these terms do not seem to have a ªxed technical connotation when ap- plied to causes. One might suppose that they indicate a kind of subordina- tion. But the ªrst and second laws are not consequences or special cases of the conservation of the total quantity of motion. The ªrst law, in fact, does not presuppose even that there is change, which is what the so-called uni- versal and primary cause is supposed to explain. The best I can do is this: God cannot create parts of matter without creating the whole; but the pri- mary cause pertains to the whole, the secondary to its parts. So there is a relation of presupposition, even though the ªrst law can in fact be derived immediately from immutability without reference to conservation of the quantity of motion, and even though the derivation of the second law like- wise bypasses the “universal and primary cause.”5 Before I turn to Menn’s paper, two remarks. Hattab asks whether there is a sense of ‘law of nature’ that would allow laws to be efªcient causes. I think that the answer is yes, but that the sense in question will be found not in natural but in moral philosophy, its original home. The second is that even if Descartes himself did not treat laws as efªcient (and as second) causes, Malebranche certainly seems to have adopted that view. It would be illuminating to examine early interpreters of Descartes to see whether and how they amplify Descartes’ exiguous remarks on the matter.

5. A violation of the ªrst law contradicts the conservation of the total quantity of mo- tion if it is an increase or decrease in the motion or volume of a body without compensat- ing change elsewhere. But Descartes includes change of ªgure in the ªrst law also. Since the second law concerns what Descartes calls the “determination” (that is, the direction, more or less) of motion, and since determination does not enter into the calculation of quantity of motion, there is, so far as I can see, no avenue from the “universal” law to this law. The motivations of the three laws, though they all include some reference to constancy or per- sistence of certain quantities or qualities, are heterogeneous. The ªrst effectively reasserts the passivity of matter, and the absence of any active principle of change in bodies (or at least of self-change). The second appeals to simplicity (the appeal is even clearer in Le Monde: a straight line is determined by two points, a second-degree curve by three; in the Principles rectilinearity is packed into the notion of [instantaneous] determination itself). Only the third law refers to quantity of motion. It alone is derived explicitly from the “universal” cause. The attempt to explicate the universal-particular distinction in terms of derivation fails. But if we consider the object of divine action, the existence of the object of the universal cause, which is the whole material world, is presupposed by the existence of the objects of the particular causes—individual parts of matter.

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3. Final causes In responding to Menn’s paper, I will concentrate on the main line of ar- gument in the ªrst part, concerning ªnal causes. I will touch on the sec- ond part, and on its illuminating discussion of art in nature, and the fate of that Aristotelian idea among the late Scholastics and in Descartes, only brieºy. An end is that on account of which something acts or exists. Suppose, for example, that nest-building is done on account of the protection it will provide to the offspring of the builder. For protection to be not only the end of building, but also its ªnal cause, there must be a relation, which Suárez calls causalitas, between the protecting and the building. Causality consists in the inºux of being. Every cause imparts being, under some as- pect, to its effects. Remembering that goodness adds to being (ens) only the ratio of ªtness, that goodness just is being with the connotation of an inclination or capacity for perfection (DM 10§1¶12; 25:332), we may say that ends impart being under the aspect of goodness or perfection. In Physiologia, I arrived at the conclusion that if natural agents are divine instruments, their actions (and they themselves) can have their ends only extrinsically. The ends we attribute to their actions do not have the relation to those actions requisite to causality, and so those ends are not ªnal causes of those actions (Des Chene 1996, p. 197). Menn, focus- sing on Suárez, takes me to task for that conclusion, and I am inclined to agree. Let me start with one major point on which we do not differ. The ends toward which natural agents act are not in those agents themselves. The end of medicine is in the doctor by virtue of her having mastered the art (cf. Menn’s Part II), but natural agents have no arts. As the common axiom (tritum axioma) puts it: “The work of nature is the work of an intelligence” (Suárez, citing Averroes, Themistius, and Galen [DM 23§10¶5]). Ends are causes only insofar as they are recognized by an intelligent agent. That is a departure from Aristotle’s own view. Suárez quotes him to the effect that “nature wants this or that on account of an end” (Suárez ibid., Aris- totle De gen. anim. 4c2), but immediately adds that this “cannot be under- stood of nature, unless on account of its author.” It is not intelligible that Nature itself should want anything. Nature acts—Suárez certainly does not deny that—but insofar as it acts toward ends, it does so in subordina- tion to God (ibid.). There is nothing in natural agents analogous to that recognition of goodness or perfection upon which intelligent agents are said to act. Are the divine ends to which they undoubtedly act still ªnal causes of those actions? Menn’s answer, in brief, is this. In every action of a created thing there must be a concurrent action of God. More precisely, God concurs

Downloaded from http://www.mitpressjournals.org/doi/pdf/10.1162/106361400568055 by guest on 26 September 2021 Perspectives on Science 155 with the agent in bringing the action into existence. That concurrent ac- tion is identical to the action of the thing. Every action, of no matter what sort of agent, is therefore identical to the action of an intelligent being, namely God. It is thus ªt to stand in the relation of causality to an end. That end is the end to which God’s concurring action—which is, as I’ve just said, identical to that of the created thing—is directed (cf. DM 23§10¶9; 25:888). Much of the argument is drawn from Suárez. Menn adds, and this is of interest in its own right, the key point being that for Suárez, concurrence and the action of the agent are one and the same. By way of responding to Menn, let me start with my argument to the conclusion Menn takes issue with. I took the problem to be that of decid- ing whether the actions of natural agents, regarded as instruments, can be said to have ªnal causes. The core of my answer is taken from Suárez, not from the section to which Menn refers, but from his section on the causal- ity of ends in rational agents. Actions commanded by the will, according to Suárez, have no intrinsic aptitude toward the ends for which the will commands them; if someone walks for health, that action is, “in itself and in its being,” precisely the same as it would have been had one been walk- ing to buy cigarettes, or for no reason at all. I concluded that in the actions of natural things too there would be no intrinsic difference between an ac- tion directed toward some divine end and an action that was, per impossibile perhaps, not so directed. Divine ends, in short, would be imposed on the ac- tions of natural agents, in something like the way we may be said to im- pose meaning on little spots of ink. That conclusion, I believed, ought to have troubled the authors I was studying more than it did. It led me, moreover, to suggest that in the treatment of the ends of natural agents and their actions in natural philosophy, what I called “cosmic” and “col- lective” ends were primary. Suárez’s summary of his position on ªnal causality is worth quoting at length: [...] in those actions, insofar as they are from natural agents, there is no proper ªnal causality, but only an aptitude (habitudo) toward a certain terminus; but insofar as they are from God, there is in them a ªnal causality, as in other external and transeunt actions of God. For the adequate principle of these actions is not only the proxi- mate natural agent, unless perhaps secundum quid, that is, in the [natural] order; but, absolutely, their ªrst principle is the First Cause; and thus in the adequate principle of such actions is in- cluded an intelligent cause intending their ends (Disp. 23§10¶6; Suárez [1856] 1965, 25:887).

Downloaded from http://www.mitpressjournals.org/doi/pdf/10.1162/106361400568055 by guest on 26 September 2021 156 Laws and Ends There is no question, moreover, but that the actions of natural agents are from God. Responding a bit later to what I called the Lucretian world—a world in which, per impossibile, natural agents operate without the concur- rence of God—Suárez writes that “just as the motions and actions of natu- ral things cannot exist without the concurrence of some rational agent, so too they cannot exist without the causality of an end” (Disp. 23§10¶9; 25:888). Menn supplements the point with argument to the effect that the concurrence referred to by Suárez is nothing other than the action it- self. That is how it can be said to have, absolutely, a ªnal cause. ‘Abso- lutely’ we may take here to mean ‘in relation to an entirely adequate princi- ple of its coming-to-be.’ It was a mistake, then, for me to have overlooked that part of Suárez’s argument, especially since I do cite the passage on the Lucretian world. Suárez’s ªrst point against the impossible example is that “nature would operate in a most orderly way tending toward an end, without the direc- tion or intention of an end, which is already absurd” (ibid.). That I took note of; but I did not take the per impossibile seriously enough. Nor did I take note of the subsequent point about concurrence, which vindicates the claim that the ends to which the actions of natural agents are directed cause those actions. Nevertheless, the larger setting is one in which natural philosophers of all stripes were, in practice, tending more and more to concern themselves with efªcient-causal explanations of natural change, and leaving the invo- cation of ªnal causes to theologians. An enormous rear-guard battle was and is still being fought on behalf of the legitimacy of ends in natural sci- ence. In the sciences of life it can be said to have been lost in the nine- teenth century, with the rise of evolutionary theory; in the physical sci- ences—Derham’s Physico-theology, the Bridgewater Treatises and so on notwithstanding—it was lost long before that. Since I was throughout the book looking backward from Descartes, and trying to understand in what ways Aristotelianism both was opposed to and prepared the ground for the new science, I may well have overemphasized the troubles confronting ªnal causes in the Jesuit authors themselves. That is essentially Menn’s di- agnosis. But the impression recorded in the book, that while teleological explanation was by no means being abandoned, the causality of ends in natural agents had become something of an embarrassment, remains, I think, accurate. Suárez, after dismissing the Lucretian world, takes up a standard objection to the claim that nature always acts towards ends. Natural agents often fail to accomplish their ends; monsters, for example, are “fre- quently generated” (Disp. 23§10¶8). But God surely cannot be frustrated in accomplishing his ends, nor can he be mistaken about the means

Downloaded from http://www.mitpressjournals.org/doi/pdf/10.1162/106361400568055 by guest on 26 September 2021 Perspectives on Science 157 by which to accomplish them. Nevertheless, his intentions, considered one by one, need not always be “absolute and efªcacious.” God “wants a perfect effect to follow” from each natural cause, but only on the condi- tion that it should follow “according to the order of natural causes.” Some- times “he permits or even wishes and intends a monster [...] either on account of the variety and beauty of the universe, or in order to allow nat- ural causes to perform their motions and follow their course.” Only excep- tionally would he concur in such an “extraordinary way” as to allow a nat- ural cause to overcome what would normally impede it, or remove the impediment; though “for the common good” he sometimes does (Disp. 23§10¶11). In such cases, where the end to which the action naturally tends is not accomplished, but does serve some larger purpose, the natural agent—for example, the monster’s parent—seems to approach the condition of the carpenter’s saw. Its action, one wants to say, has no end. Only as part of some larger collective or joint action, like the production of variety and beauty in nature, can it be said to have an end. It is true that the com- ing-to-be of that action, considered as an act of concurrence by God, can still be brought under the schema of the ªnal cause. But the end intended is not the end of that action, except as part of some larger action, and is in that sense extrinsic to it, as health to walking. Consider the often-discussed case of monsters. We may distinguish (1) the end toward which the action is or would be directed from the point of view of the agent, and (2) the end on account of which God concurs. We may suppose, moreover, initially that God has, for each creature and in each concurrence with that creature’s actions, the particular intention to promote that creature’s good, or at least no intention to promote harm to it: as the slogan went, nothing tends to its own destruction, nor, presum- ably, does God intend ab initio that any good thing should perish. But God also has general and antecedent intentions—to let nature run its course as much as possible, for example, or to economize on miracles. In normal births the particular and the general intention are consistent. So we may include among the ends on account of which God concurs with the action of the creature the end to which the action would be directed (from the standpoint of the creature acting). But in monstrous births the two are not consistent. The only end on account of which God concurs is that contained in his general intentions—for example, that nature should run its course. Notice the difference with Aristotle. For Aristotle, in the case of mon- strous births, the end is, as in any birth, a normal offspring but by chance (the action of other agents, for example, or the inadequacy of the matter of generation, or too much heat in the womb) the end was not attained. For

Downloaded from http://www.mitpressjournals.org/doi/pdf/10.1162/106361400568055 by guest on 26 September 2021 158 Laws and Ends Suárez, on the other hand, the only end actually present in the ac- tion—namely, the divine end of letting nature run its course—was at- tained. The end of normal birth, which in Aristotle is in the progenitor or the seed, is for Suárez in God; God cannot have inconsistent ends, and so in monstrous birth, there is no such end. To preserve ªnal causality in the actions of natural agents, once the “art in things” has been removed from them, Suárez shifts his attention from the particular purposes of those agents, which so long as they were distrib- uted among many agents could easily be inconsistent, to the antecedent general intentions (voluntates) of God, which cannot be inconsistent. To move from a physics of powers and natural ends to a physics of laws—when those laws are thought to be divine intentions—need not be a move against teleology. On the contrary, it strengthens God’s hand, and eliminates what Malebranche, for one, saw to be a hidden polytheism in Aristotle’s physics.6 Arriaga holds that an action, considered apart from whatever end itmight serve, is useful toward that end only extrinsically (see Des Chene 1996, p. 197). Considering the action thus apart from ends, one may still determine its efªcient cause. That is the way of Descartes, for whom di- vine ends in nature are inscrutable. But for Suárez, a science that never considers actions except in abstraction from their ends is incapable of giv- ing an adequate cause for their existence. That is true even of the birth of monsters. In respect of the monster itself, its parents, or its species, it may seem to have no end—that is, it may seem that nothing has imparted be- ing to it under the aspect of the good. But we are to consider the ends of action absolutely—in respect to God’s total and universal external act of creation, conservation, and concurrence. It is in that act, and perhaps only in that act, that we can say without qualiªcation that God has communi- cated his goodness to the world.

6. The particular intention that God could have had, had he (consistently with his power, but not with his goodness) produced only the one creature, is effaced in favor of the general intention he did have. “One may say that in a sense God had no intention [dessein] to make monsters: for it seems to me evident that if God had made just one ani- mal, he would never have made it monstrous. But having had the intention to produce a wonderful work by the simplest means, and to bind all creatures with one another, he foresaw certain effects that would follow necessarily from the order and the nature of things, and that did not deter him from his intention. For although a monster by itself is an imperfect work, still when it is joined with the rest of God’s creatures, it does not make the world imperfect, or unworthy of the wisdom of the Creator, when we compare the work with the simplicity of the ways by which it is produced” (Malebranche [1712] 1962, liv2pt1c7§3, 1:245). On polytheism and substantial forms, see liv6pt2c3, 2:309–320.

Downloaded from http://www.mitpressjournals.org/doi/pdf/10.1162/106361400568055 by guest on 26 September 2021 Perspectives on Science 159 That God, having created natural agents of various kinds, should choose mostly to allow them to follow their natural course is reminiscent of Hattab’s suggestion that the creation of a world of matter in motion places “constraints” on God. God is an artist; but even the greatest artists, it would seem, must accept the limitations of the media they work in. In the second part of his paper, Menn notes that “Aristotle takes arts for nat- ural causes,” including God and the soul; in natural agents, art, being un- changed in its exercise, can be thought of as an unmoved mover; such un- moved movers are “regulators and sources of constancy in [natural] change”; and only because there are such unmoved movers is a science of natural change possible. But Aristotle’s unmoved movers are ªnite, lim- ited in their scope and force. Like human artists, they can be frustrated, they can impede one another’s actions. God is not limited; considered in himself, he cannot be frustrated or impeded by another agent. Yet even his intention, if we follow Suárez’s line of reasoning, is not realized except quasi conditionata, “as if condi- tioned,” namely by the “general and antecedent” will to concur in the nat- ural order he himself has founded. That will alone is the source of con- stancy in nature; if there is a science of nature only where there is con- stancy, then in God alone can we hope to ªnd an adequate cause of the nat- ural order. Concurrence, as Menn notes, entails that there are not, and can- not be, any other unmoved movers (although it should be noted that Suárez argues that concurrence is not an action, prior to that of the agent, that moves the agent to act). This raises questions both about the efªcacy of natural agents—if indeed genuine efªcacy requires something akin to an art in the agent—and about the role of the ªnal cause in their actions. For at least one can say that, unlike the doctor healing a patient, they are not exercising the art which guides their actions. Even in bruta, for all their “sagacity and industry,” the causality of the end is “imperfect of its kind.” Because animals do not cognize the good or the lovable under the reason of the good or the lovable, but only recognize the thing that is good or lovable and pursue it by instinct, in them there is, “as it were, a mate- rial motion of the end, rather than a formal motion” (Suárez [1856] 1965, 25:889). Having written a book that was, among other things, a brief against anachronism, I am chastened to think that, as Menn puts it, I have made Suárez and company “sound too much like later physico-theologians.” Sometime before embarking on Physiologia I delved into the literature of physico-theology in the eighteenth century; I came to think of Descartes as far more radical in his rejection of all such comforting reconciliations of science and theology than his Leibnizian and Newtonian successors—

Downloaded from http://www.mitpressjournals.org/doi/pdf/10.1162/106361400568055 by guest on 26 September 2021 160 Laws and Ends more radical, indeed, than any other natural philosopher, except Spinoza, in the seventeenth century. There is, however, one point on which Descartes and the Jesuit Scholas- tics are in agreement. The observance of a natural order is for Suárez the consequence of divine will. Insofar as natural order must be observed if a science of nature is to be possible, it too is dependent upon the divine will and therefore upon God’s benevolence. The same holds for Descartes, but for quite different reasons. The derivation of natural laws is based not on any, so to speak, contentful volition of God, but only on the formal charac- ter of every divine volition: in particular, on its immutability. God’s good- ness has no role in that derivation. But to the extent that the derivation is incomplete, and perhaps cannot be completed, Descartes must then ap- peal, at least implicitly, to God’s benevolence. The sixth Meditation rests our knowledge of extended substance on God’s veracity, which in turn rests on his goodness. The guarantee thus proved is extended to include even particular facts, like the size of the Sun (Descartes 1964, 7:80); pre- sumably it extends also to the rules of collision. But the derivation of the third law, on which those rules rely, needs a premise to the effect that there is no action at a distance. One might argue that a world so arranged that motion was transferred among noncontiguous bodies would be one in which we would be impelled falsely to conclude that in bodies there are occult powers, when in fact they have none, being still nothing other than extended substances. There remains, then, a small but signiªcant residue of the order that, according to Descartes’ predecessors, was bestowed by God on nature. That residue is the basis on which hope remains, despite the inroads of skepticism, for human knowledge of the natural world. On Menn’s account, the notion of an “art in things,” apart from rational agency, had become a puzzle long before Descartes. In agents without rea- son, “art” must be understood simply as the overall outcome, foreseen by God, of certain otherwise blind powers which God has put into things. Their activity, it would seem, consists less in their apparent directedness (“apparent” because it must be referred to God’s will, and is therefore not intrinsic to things themselves) than in their spontaneity, in the fact that ªre, say, will burn wood if not prevented. But if that spontaneity can like- wise be treated as apparent, by treating it as the necessity with which events governed by law occur, then nothing remains of the Aristotelian notion except the inferrability from natural regularities of a benevolent in- tention behind them. But for Descartes, such inferences are, except where human beings are concerned, perilous, even presumptuous. Nothing, then, remains of the Aristotelian notion. The regularity of natural events, derived from the formal immutability of God’s will, provides no guide to the content of that will. The apparent spontaneity of natural causes is

Downloaded from http://www.mitpressjournals.org/doi/pdf/10.1162/106361400568055 by guest on 26 September 2021 Perspectives on Science 161 nothing other than an expression of the creative (hence conserving) power of God, whom we must suppose to be a rational agent even if his reasons must remain incomprehensible to us. There are, evidently, many routes to understanding even that part of the transformation of natural philosophy in the seventeenth century which concerns only Descartes and his Jesuit predecessors. Like Physiologia itself, Hattab’s and Menn’s papers consider primarily intellectual factors; they present what one might call an enlarged, enlightened, but still “internal” history. Enlarged, that is, to include metaphysical and theological con- cepts and opinions; enlightened insofar as they respect the frameworks within which the historical agents themselves operated rather than impos- ing another, perhaps alien, framework. Two questions may be raised. The ªrst is to what extent the Cartesian philosophy (and of course also the Jesuit texts) are representative of the pe- riod. Is, for example, the emphasis on the Aristotelian, as contrasted with, say, the atomist or Neoplatonist, background warranted? In Descartes’ case, I think, the emphasis is warranted. Although he opposes his philoso- phy to that of the atomists also, in the Principles especially, and was no doubt well aware of the opprobrium traditionally attaching to atomism, his ambitions were primarily directed toward supplanting the Aristotelian philosophy. It is likely that he did, at one point or another, read and use the works of Sebastian Basso, Daniel Gorlaeus, and other atomist or corpuscularian philosophers, just as in the Treatise on Man he adapts Galen and Jean Fernel. A fuller picture of the resources on which Descartes drew, even one that remained internal, would have to take those texts also into account, as Garber (1992) and Ariew (1999) have done. Nevertheless, the primary intellectual contrast, not only for Descartes but for many of his contemporaries, was between the “new philosophy,” mechanist in tendency though not exclusively so, and that of the Schools, of which the Jesuit textbooks were taken to be representative by the new philosophers themselves. That the picture they drew of the School philos- ophy is tendentious, that it failed to distinguish divergences among Aris- totelians themselves, is true enough, and we should not be taken in by it. Nevertheless, as often happens, it was the appearances that mattered, in- cluding that of a uniform School philosophy. As for Cartesianism itself, it seems clear if one reads, for example, the éloges by Fontenelle of members of the Académie des Sciences, that for most natural philosophers of the mid-seventeenth century Cartesianism was the new philosophy, with Gassendi’s atomism a distant second. Earlier in this paper I proposed, following Grant, that Aristotelianism be regarded as a collection of concepts and methods (to which one should add its characteristic literary forms and institutional embodiments),

Downloaded from http://www.mitpressjournals.org/doi/pdf/10.1162/106361400568055 by guest on 26 September 2021 162 Laws and Ends which, in keeping with Sperber’s view, one should treat as a kind of epi- demic. The same holds for Cartesianism: it is one thing to clarify and ex- plain Cartesian ideas, as the papers here have done, and another to explain how those ideas took hold when others did not. To answer that sort of question clearly internal history will not sufªce. However appealing, how- ever coherent the Cartesian system might have been when gauged by sev- enteenth-century standards of rational acceptability, still the adoption of Cartesianism by key ªgures in the Dutch universities (and the relative tol- erance in which teaching took place there), or the later role of the salons in Paris in its becoming fashionable, certainly must be brought into the ex- planation of the spread of the Cartesian virus. This brings me to the second question. Implicitly, Hattab, Menn, and I are proposing that the transfer of allegiance among many philosophers from Aristotelianism to Cartesianism, or to the new natural philosophy, should be treated as if those philosophers were attuned mostly to the con- cepts and arguments therein. That this is an idealization can be inferred, for example, from the treatment that the “sect of Cartesians” itself received from its opponents, who accused it—just as the Cartesians accused the School philosophers—of slavish adherence to the master. Even taking into account the tendency to caricature, one may suppose that Cartesianism might well have been accepted on grounds no more rational than the praejudicia—the opinions picked up before the age of reason—that in Des- cartes’ view explained the prevalence of Aristotelianism. When one of Molière’s characters exclaimed, “J’aime ses tourbillons,” it was no doubt not a close reading of the Principles or of Rohault that was supposed to have moved her. The question, then, is how much weight should be given to the intel- lectual characteristics of doctrines, as contrasted, for example, with the so- cial characteristics of those who hold them. Two answers suggest them- selves. Neither is conclusive, neither is universally applicable. The ªrst is that Cartesian philosophy, as exempliªed in his texts and those of his fol- lowers, does have such characteristics: it is accompanied by arguments, it claims to be coherent and systematic, it offers reasons to reject opposing doctrines. Even if it is a virus, it has, like its biological analogues, an in- ternal structure that almost certainly helps account for its effects. The second is that in the audience for natural philosophy in that period (or in ours), some members were attuned to just those features to which in- tellectual historians also are attuned. Huygens, Newton, and Leibniz may have had many motives for rejecting various of Descartes’ claims. But for each of them, those motives included the incoherence and experimental inadequacy of Cartesian physics. They were natural philosophers by train- ing; to be trained as a natural philosopher is, among other things, to be-

Downloaded from http://www.mitpressjournals.org/doi/pdf/10.1162/106361400568055 by guest on 26 September 2021 Perspectives on Science 163 come attuned to the consistency and experimental adequacy of doctrines in natural philosophy, and to enter into competition with one’s peers pre- cisely by way of arguing for or against doctrines on those grounds. So too Descartes himself, if we think of him as a “player” in the learned world of Paris and Utrecht, presented himself as a reasoner and an experimenter, and not, for example, as a magus. The Discourse is a narrative not of receiv- ing the beatiªc vision, or of gaining esoteric insight into the secrets of na- ture, but of ªnding a method and making discoveries. Attunement is an ideal. Like acting out of duty according to Kant, it is an ideal which one can never be certain of attaining. The intellectual historian supposes—a supposition always open to question in particular cases—that some success, by the agents’ own lights, has been attained by the agents she deals with, partial but nonetheless genuine. The study of the conceptual and argumentative structure of doctrines can therefore be accounted a study of certain causes of the social effects of those doc- trines.

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