This book analyses the concept of scientific explanation developed by French disciples of Descartes in the period 1660-1700. Clarke examines the views of authors such as Malebranche and Rohault, as well as those of less well-known authors such as Cordemoy, Gadroys, Poisson and R'egis. These Cartesian natural philosophers developed an understanding of scientific explanation as necessarily hypothetical, and, while they contributed little to new scientific discoveries, they made a lasting contribution to our concept of explanation--generations of scientists in subsequent centuries (...) followed their lead. (shrink)

In this paper, I consider Descartes’ Sixth Meditation dropsy passage on the difference between the human body considered in itself and the human composite of mind and body. I do so as a way of illuminating some features of Descartes’ broader thinking about teleology, including the role of teleological explanations in physiology. I use the writings on teleology of some ancient authors for the conceptual (but not historical) help they can provide in helping us to think about the Sixth Meditation (...) passage. From this, I draw several points, most notably that the Sixth Meditation passage is primarily concerned with the natures of body and composites, and that the issue of teleological explanation is derivative of this primary interest. So, we – and Descartes – must come to terms with what he takes the nature of the composite to be such that it has an intrinsic end-referred nature which grounds teleological explanations. I consider three possibilities: the human composite is a third type of substance – a hylomorphic substance; there is a sort of “satisfaction” relationship between mind and body (each of which retains its own distinct nature in the composite) such that the mind confers teleological value on the body; and there is a sort of “satisfaction” relationship between mind and body (each of which retains its own distinct nature in the composite) such that the mind recognizes teleological value in the body. None of these interpretations is without problems. So in the concluding section, I sketch a program for future research, specifically, trying to render Descartes’ teleological thinking consistent by distinguishing between the metaphysical natures of things (the concern of his Sixth Meditation passage) and the physical natures of things (his concern in his physiological writings). (shrink)

In this chapter, I examine similarities and divergences between Du Châtelet and Descartes on their endorsement of the use of hypotheses in science, using the work of Condillac to locate them in his scheme of systematizers. I conclude that, while Du Châtelet is still clearly a natural philosopher, as opposed to modern scientist, her conception of hypotheses is considerably more modern than is Descartes’, a difference that finds its roots in their divergence on the nature of first principles.

Alison Simmons, in Simmons (1999), argues that Descartes in Meditation Six offered a teleological account of sensory representation. According to Simmons, Descartes’ view is that the biological function of sensations explains both why sensations represent what they do (i.e., their referential content) and why they represent their objects the way they do (i.e., their presentational content). Moreover, Simmons claims that her account has several advantages over other currently available interpretations of Cartesian sensations. In this paper, I argue that Simmons’ teleological (...) account cannot be sustained for both theoretical and textual reasons and that it does not have the advantages it is claimed to have. (shrink)

This article thinks about changes in the conception of hypothesis during the early modern period. It explains that during this period there was an urgency to redefine human knowledge so that uncertainty became one of its inevitable and acceptable features, and certainty was replaced by probability as an adequate achievement in knowledge of the natural world. It discusses Isaac Newton's deep-seated rejection of hypotheses and the assumption that their use in natural philosophy would compromise its status as genuine scientific knowledge.

Despite eschewing the utility of ends or purposes in natural philosophy, Descartes frequently engages in functional explanation, which many have assumed is an essentially teleological form of explanation. This article considers the consistency of Descartes's appeal to natural functions, advancing the idea that he is utilizing a non-normative, non-teleological form of functional explanation. It will be argued that Cartesian functional analysis resembles modern causal functional analysis, and yet, by emphasizing the interdependency of parts of biological systems, is able to avoid (...) many of the problems attendant upon modern causal theories. It is for this reason, if no other, that the study of Descartes's natural philosophy should be of interest to contemporary theorists of functional analysis. (shrink)

Despite holding to the essential distinction between mind and body, Descartes did not adopt a life-body dualism. Though humans are the only creatures which can reason, as they are the only creatures whose body is in an intimate union with a soul, they are not the only finite beings who are alive. In the present note, I attempt to determine Descartes'' criteria for something to be ''living.'' Though certain passages associate such a principle with the presence of a properly functioning (...) heart, I show that there are important reasons for also understanding life in terms of a degree of complexity of design. (shrink)

Monte Johnson examines one of the most controversial aspects of Aristiotle's natural philosophy: his teleology. Is teleology about causation or explanation? Does it exclude or obviate mechanism, determinism, or materialism? Is it focused on the good of individual organisms, or is god or man the ultimate end of all processes and entities? Is teleology restricted to living things, or does it apply to the cosmos as a whole? Does it identify objectively existent causes in the world, or is it merely (...) a heuristic for our understanding of other causal processes? Johnson argues that Aristotle's aporetic approach drives a middle course between these traditional oppositions, and avoids the dilemma, frequently urged against teleology, between backwards causation and anthropomorphism. Although these issues have been debated with extraordinary depth by Aristotle scholars, and touched upon by many in the wider philosophical and scientific community as well, there has been no comprehensive historical treatment of the issue. Aristotle is commonly considered the inventor of teleology, although the precise term originated in the eighteenth century. But if teleology means the use of ends and goals in natural science, then Aristotle was rather a critical innovator of teleological explanation. Teleological notions were widespread among his predecessors, but Aristotle rejected their conception of extrinsic causes such as mind or god as the primary causes for natural things. Aristotle's radical alternative was to assert nature itself as an internal principle of change and an end, and his teleological explanations focus on the intrinsic ends of natural substances - those ends that benefit the natural thing itself. Aristotle's use of ends was subsequently conflated with incompatible 'teleological' notions, including proofs for the existence of a providential or designer god, vitalism and animism, opposition to mechanism and non-teleological causation, and anthropocentrism. Johnson addresses these misconceptions through an elaboration of Aristotle's methodological statements, as well as an examination of the explanations actually offered in the scientific works. Reviewed in: Notre Dame Philosophical Review 2006.06.15; Bryn Mawr Classical Review 2006.08.37; Il-Sole – 24 Ore 6 Aug. 2006; Philosophy in Review 26 (2006): 360-2; Rhizai 3 (2006): 171-8; Journal of the History of Philosophy 45 (2007): 323-4; Ancient Philosophy 27 (2007): 191-200; Phronesis 52 (2007): 248-9; Isis 98 (2007): 375; Aestimatio 4 (2007) 146-152; The British Journal for the History of Science 41 (2008): 129-130. The European Legacy 14 (2009); La Cultura 47 (2009): 174-175; Sean M. Row, Teleology in Political Contexts: an assessment of Monte Ransome Johnson’s “Aristotle on Teleology”. (A thesis presented to the faculty of the college of arts and sciences of Ohio University, 2009.). (shrink)

" Il est à remarquer en tout ce que j'écris que je ne suis pas l'ordre des matières mais seulement celui des raisons, c'est-à-dire que je n'entreprends point de dire en un même lieu tout ce qui appartient à une matière, à cause qu'il me serait impossible de la bien prouver y ayant des raisons qui doivent être tirées de bien plus loin les unes que les autres, mais en raisonnant par ordre, a facilioribus ad difficiliora, j'en déduis ce que (...) je puis, tantôt pour une matière, tantôt pour une autre, ce qui est à mon avis le vrai chemin pour bien trouver et expliquer la vérité. " (Descartes à Mersenne, 24 décembre 1640). " Si l'ordre analytique est le seul à procurer la démonstration valable de la philosophie, si les Méditations qui se développent rigoureusement selon cet ordre, permettent seules de comprendre à coup sûr l'ensemble de la doctrine, il n'y a pas d'autre méthode pour comprendre les Méditations elles-mêmes que de mettre en évidence cet ordre par lequel seul elles démontrent leur vérité. " (Martial Gueroult). (shrink)

In lieu of an abstract, here is a brief excerpt of the content:Journal of the History of Philosophy 39.1 (2001) 49-75 [Access article in PDF] Sensible Ends:Latent Teleology in Descartes' Account of Sensation Alison Simmons One of Descartes' hallmark contributions to natural philosophy is his denunciation of teleology. It is puzzling, then, to find him arguing in Meditation VI that human beings have sensations in order to preserve the union of mind and body (AT VII 83). 1 This appears to (...) be just the sort of teleological explanation that he proscribes. Descartes' Anglo-American commentators have had little to say about the teleological overtones of his claims about sensation. His French commentators acknowledge these overtones, but seem largely untroubled by them. 2 It is worth pausing to be troubled, for a closer analysis reveals that Descartes' famous proscription against teleology is not as simple as it is generally thought to be. In the first half of this essay, I argue that Descartes advocates a genuinely teleological conception of the senses. My aim is not to charge Descartes with employing illicit teleology, but to argue that there is a place for teleology even in his revisionist natural philosophy. Accordingly, in the second half of this essay, I argue that Descartes' assault on teleological explanation is [End Page 49] not a sweeping assault on finality, but a more directed attack on particular uses of ends in natural philosophy. Descartes' assault leaves standing a form of teleological explanation that proves crucial to his own treatment of sensation. 1. Descartes' Rejection of Teleological Explanation at a Glance A teleological explanation is one that purports to account for something in terms of its ends or its function relative to the ends of the system of which it is a part. Aristotle's physics provides many classic examples: plants produce leaves for the protection of their fruit; spiders spin webs in order to catch food; animals grow sharp front teeth and dull back teeth in order to facilitate biting and chewing respectively; eyes are for seeing. According to Aristotle, all natural phenomena are directed toward ends and no explanation is complete without a teleological component that specifies the end for the sake of which the phenomenon occurs. Indeed ends take explanatory priorityover other causes: "Both causes [the end and the matter] must be stated by the student of nature, but especially the end; for that is the cause of the matter, not vice versa." 3 And: [T]he causes concerned in natural generation are, as we see, more than one. There is the cause for the sake of which [the end], and the cause whence the beginning of motion comes [the efficient cause]. Now we must decide which of these two causes comes first, which second. Plainly, however, that cause is the first which we call that for the sake of which. For this is the account of the thing, and the account forms the starting-point.4In other words, Aristotle argues that natural substances have the matter they do, have the parts or organs they do, are organized as they are and act as they do for the sake of their ends. To explain why things are as they are, the natural philosopher must therefore explain the ways in which they contribute to ends.Among the late scholastic Aristotelians familiar to Descartes there is considerable debate concerning the causal efficacy of ends. Genuine final causation, in which something is said to be acted on by an end, is limited to the intentional behavior of rational agents who consciously recognize their ends: only something that recognizes an end can be "moved" by one. Even here the sort of causation involved is peculiar: a rational agent is "moved" by an end insofar as the end induces a "metaphorical motion" toward (or desire for) the end in the agent's will. 5 While these scholastic Aristotelians resist attributing final causation [End Page 50] to non-rational creatures, they nevertheless persist in attributing ends to them. When Toletus, Rubio, the Coimbrans and Suarez take up the question whether nature acts propter finem, each answers it affirmatively: natural... (shrink)

. The concept of bodily health is problematic for mechanists like Descartes, as it seems that they need to appeal to something extrinsic to a machine, i.e., its purpose, to determine whether the machine is working well or badly, and so healthy or unhealthy. I take issue with this claim. By drawing on the history of medicine, I suggest that in the seventeenth century there was space for a non-teleological account of health. I further argue that mechanists can and did (...) appeal to structural integrity, as a non-teleological notion of form, to ground the norms required for ascriptions of health. (shrink)

Alison Simmons, in Simmons (1999), argues that Descartes in Meditation Six offered a teleological account of sensory representation. According to Simmons, Descartes’ view is that the biological function of sensations explains both why sensations represent what they do (i.e., their referential content) and why they represent their objects the way they do (i.e., their presentational content). Moreover, Simmons claims that her account has several advantages over other currently available interpretations of Cartesian sensations. In this paper, I argue that Simmons’ teleological (...) account cannot be sustained for both theoretical and textual reasons and that it does not have the advantages it is claimed to have. (shrink)

Dennis Des Chene's Physiologia: Natural Philosophy in Late Aristotelian and Cartesian Thought reconstructs the discourse of late scholastic natural philosophy, and assesses Descartes' agreements and disagreements. In a critical discussion, I offer a different interpretation of late scholastic theories of final causality and of God's concursus with created efficient causes. Fonseca's and Suárez' conceptions of final causality in nature depend on their claim that a single action can be the action of two agents at once--in particular, of God and of (...) a creature. I discuss both their theory of action and its implications for natural teleology. I then compare Descartes, emphasizing his demolition of the Aristotelian hierarchy of causes, with unmoved movers regulating the action of inferior moved movers. Aristotle argues that unmoved causes are needed to produce a stable world-order; he takes arts as his models of unmoved causes, and uses this model to support natural teleology. Descartes radically simplifies this system by denying all unmoved movers other than God, and denying anything analogous to an art in non-human nature. I explore the implications for Descartes' notion of concursus and his criticism of natural teleology, and discuss his resulting difficulties in explaining natural stability. (shrink)

This book consists of a collection of essays written between 1965 and 1981. Some have been published elsewhere; others appear here for the first time. Although dealing with different figures and different periods, they have a common theme: all are concerned with examining how the method of hy pothesis came to be the ruling orthodoxy in the philosophy of science and the quasi-official methodology of the scientific community. It might have been otherwise. Barely three centuries ago, hypothetico deduction was in (...) both disfavor and disarray. Numerous rival methods for scientific inquiry - including eliminative and enumerative induction, analogy and derivation from first principles - were widely touted. The method of hypothesis, known since antiquity, found few proponents between 1700 and 1850. During the last century, of course, that ordering has been inverted and - despite an almost universal acknowledgement of its weaknesses - the method of hypothesis (usually under such descriptions as 'hypothetico deduction' or 'conjectures and refutations') has become the orthodoxy of the 20th century. Behind the waxing and waning of the method of hypothesis, embedded within the vicissitudes of its fortunes, there is a fascinating story to be told. It is a story that forms an integral part of modern science and its philosophy. (shrink)

ne of the leading problems for Cartesian dualism is to provide an account of the union of mind and body. This problem is often construed to be one of explaining how thinking things and extended things can causally interact. That is, it needs to be explained how thoughts in the mind can produce motions in the body and how motions in the body can produce sensations, appetites, and emotions in the mind. The conclusion often drawn, as it was by three (...) of Descartes's illustrious successors, Malebranche, Spinoza, and Leibniz, is that mind and body cannot causally interact.' I mention this problem of the interaction between thinking things and extended things only to distinguish it from the problem concerning the union of mind and body which I wish to discuss. Some commentators, such as Daisie Radner, maintain that the.. (shrink)

In lieu of an abstract, here is a brief excerpt of the content:Cartesian CompositesPaul HoffmanTowards the end of a paper in which I argued that Descartes thinks a human being is a genuine unity, I invited other commentators to come to Descartes’s defense by accounting for his apparently contradictory claims that a human being is an ens per se and that it is an ens per accidens.1 These claims seem to be contradictory, because in saying that a human being is (...) an ens per se, Descartes appears to be asserting that a human being is genuinely one, and in saying that a human being is an ens per accidens, he appears to assert that a human being is not genuinely one, but instead is a mere heap or aggregate. In the ensuing eleven years no one has taken up my invitation, except to argue that I was mistaken in claiming that Descartes thinks a human being has per se unity in any robust sense.2In this paper I will take up the challenge myself, having noticed a similarity between Descartes’s account of the unity of composite substances and his account of composite figures having true and immutable natures. After showing how he can consistently maintain that a human being is both an ens per se and ens per accidens in roughly the same way he can consistently maintain that composite figures both do and do not have true and immutable natures, I will try to respond to criticisms of my claim that he thinks of a human being as a substance or an ens per se.Let me begin with an analysis and comparison of two passages from the Objections and Replies. In the first, from the Replies to the First Objections, Descartes [End Page 251] discusses composite figures. In the second, from the Replies to the Fourth Objections, Descartes discusses composite substances.Next, to remove the other part of the difficulty, it should be noted that those ideas which do not contain true and immutable natures, but contain only ones which are fictitious and composed by the intellect, can be divided by the same intellect, not only through abstraction, but through a clear and distinct operation, so that any ideas which the intellect cannot so divide were undoubtedly not composed by it. As, for example, when I think of a winged horse, or an actually existing lion, or a triangle inscribed in a square, I easily understand that I can also in opposition think of a horse without wings, a non-existing lion, a triangle without a square, and so on; from which it follows that these do not have true and immutable natures. But if I think of a triangle or a square (I do not speak here of a lion or horse because their natures are not clearly evident to us), then certainly whatever I apprehend as contained in the idea of a triangle, as that its three angles are equal to two right angles, etc., I will truly affirm of the triangle, and of the square whatever is found in the idea of the square. For even if I can understand a triangle, abstracting from the fact that its angles should equal two right angles, I cannot nevertheless deny that of it by a clear and distinct operation, that is, correctly understanding this is what I say. Furthermore, if I consider a triangle inscribed in a square, not in order to attribute to the square those things which pertain only to the triangle or to the triangle those things which pertain to the square, but in order to examine only those things which arise from the conjunction of the two, then its nature will be no less true and immutable than the square or triangle alone, and it will be permitted to affirm that the square is not less than twice the triangle inscribed in it and similar things which pertain to the nature of this composite figure. (AT VII 117–8; CSM II 83–4)3I am not unaware that some substances are commonly called ‘incomplete.’ But if they are said to be incomplete because they cannot exist per se alone, I confess that it seems contradictory to me that... (shrink)

This journal article has been superseded by a revised version, published in the collection _Essays on the Philosophy and Science of Rene Descartes_, ed. by Stephen Voss (Oxford University Press, 1993), 259–287.

Recent Cartesian scholarship postulates two Descartes, separating Descartes into a scientist and a metaphysician. The purpose varies, but one has been to show that the metaphysical Descartes, of the Meditations, is less genuine than the scientific Descartes. Accordingly, discussion of God and the soul, the evil demon, and the non-deceiving God were elements of rhetorical strategy to please theologians, not of serious philosophical argumentation. I agree in finding two Descartes, but the two I identify are not scientist and philosopher, but (...) practitioner and methodologist of the mathematical sciences on the one hand, and metaphysician of a new, general science of nature on the other. This chapter examines the transition to the second Descartes, and especially the metaphysical turn. It proposes that although Descartes' doubt was methodological and he felt no serious threat from skepticism and absolute certainty was not his primary goal. Rather, the doubt was used to reform the intellect, or to teach the use of the pure intellect (and to obtain certainty in that domain). Further, Descartes' metaphysics was primarily in the service of his natural philosophy (where in the main he did not claim absolute certainty). He did not talk about God and the soul in order to fool the theologians. His discussion of the relation between God and human reason was part of a metaphysical strategy in which, through his doctrine on the eternal truths, he separated knowledge of the first principles of natural philosophy (gained by the natural light) from theological cognition (through the light of grace), thereby seeking to render his metaphysics distinct from the proper domain of theology. (shrink)

ZusammenfassungNach Descartes besteht der Hylomorphismus nur beim Menschen und sonst gar nicht. Die Cartesische Lehre wird an Hand von vier Fragen untersucht. 1. Wie sehen die Texte aus, in denen Descartes gegen die substantiale Form im allgemeinen bzw. fur die substantiale Form im Men schen spricht? 2. Wie verhält sich die Cartesische Lehre von der Stelle des Menschen in der Natur zur Aristotelischen Fassung? 3. Wie hat Descartes das scholastische Modell umgedeutet, um zu seiner Kritik der substantialen Form zu gelangen? (...) 4. Welche Rolle spielt die substantiale Form in der Entwicklung der Cartesischen Metaphysik, und wie verandert sich der Substanzbegriff durch diese Entwicklung?SummaryAccording to Descartes hylomorphism occurs in man only and nowhere else. The Cartesian doctrine is examined in relation to four questions. 1. What are we to make of the texts in which Descartes speaks against substantial form in general and for substantial form in the human case? 2. How does Descartes's doctrine of the place of man in nature compare with Aristotle's? 3. How did Descartes reinterpret the scholastic model, in order to arrive at his critique of substantial form? 4. What role does substantial form play in the development of Descartes's metaphysic, and how is the traditional concept of substance altered by this development?RésuméPour Descartes, l'hylomorphisme ne se trouve que chez I'homme, et nulle part ailleurs. L'auteur examine cette doctrine en essayant de répondre à quatre questions: 1. Que peut‐on tirer des textes où Descartes se prononce contre les formes substantielles dans le cas général et pour ces mêmes formes dans le cas de l'homme? 2. Comment se présente, comparée à celle d'Aristote, la doctrine cartésienne de la place de I'homme dans la nature? 3. Comment Descartes, réinterpré‐tant le modéle scolastique, est‐il arrivéà sa critique des formes substantielles? 4. Quel rôle les for mes substantielles jouent‐elles dans le développement de la métaphysique cartésienne et en quoi le concept traditionnel de substance a‐t‐il été affecté par ce développement? (shrink)

This is a review of Stephen Gaukroger's book Descartes's System of Natural Philosophy.

rené descartes famously and explicitly rejects appeals to final causes in natural philosophy, suggesting that such appeals depend on knowledge of God’s inscrutable ends.For since I now know that my own nature is very weak and limited, whereas the nature of God is immense, incomprehensible and infinite, I also know without more ado that he is capable of countless things whose causes are beyond my knowledge. And for this reason alone I consider the whole kind of causes, customarily sought from (...) an end, to be totally useless in physics; there is considerable rashness in thinking myself capable of investigating God’s ends.1This rejection did not go unnoticed nor without controversy. In the Fifth.. (shrink)

L'etude historique du principe de vie dans l'oeuvre de Descartes et dans celle de ses predecesseurs souligne notamment l'enjeu de la scission cartesienne entre l'ame et les phenomenes biologiques. Elle permet de comprendre, dans sa nouveaute radicale, la notion de principe de vie chez Descartes, qui associe la decouverte recente de la circulation du sang par W. Harvey, a une explication mecanique de la chaleur du coeur. Du traite de L'Homme aux Passions de l'ame, Descartes identifie en effet la notion (...) de principe de vie a la chaleur contenue dans le coeur, nourrie par la circulation du sang. Une telle conception s'oppose a la vision aristotelicienne, ou la biologie et la psychologie sont etroitement liees, ainsi qu'aux adeptes du panpsychisme que Descartes a critiques: Campanella et Henry More. (shrink)

In Mechanization of the Heart: Harvey and Descartes Thomas Fuchs discusses the similarities and differences of the views of the two seventeenth-century scholars William Harvey and Rene Descartes on the beart and circulationof the blood; Fuch traces the reception of the two views in the medical literature of the time and the influence both views had. In Mechanization of the Heart: Harvey and Descartes Thomas Fuchs begins by comparing the views of William Harvey [1578-1657] and Rene Descartes [1596-1650] on the (...) heart and the circulation of the blood through the body. These two seventeenth-century scholars -- one a British medical doctor, the other a French philosopher and mathemetician -- differed substantially in their beliefs: they both accepted the idea of circulation of the blood, but differed on the action of the heart. Fuchs traces the ways the opposing views were received, revised, rejected, or renewed in succeeding generations by medical writers in various parts of Europe. He then examines Harvey's approach to cardiac and circulatory physiology, mainly through an examination of Harvey's book De motu cordis: he follows with a discussion of the background in Aristotelian philosophy that was the requirement for all studies in medicineand how that affected Harvey's beliefs. Fuchs then turns to Descartes's presentation of Harvey's views and shows how his view, rather than Harvey's, was accepted in Europe at that time. Marjorie Grene brings to the translation herdistinguished background in philosophy and her keen insights into medical philosophy. Thomas Fuchs teaches psychiatry at the Rupert-Karls-Universitat, Heidelberg. MarjorieGrene is Professor Emeritus of Philosophy at the University of California at Davis, and Adjunct Professor and Honorary Distinguished Professor of Philosophy at Virginia Tech University. (shrink)

Towards the end of his life, Descartes published the first four parts of a projected six-part work, The Principles of Philosophy. This was intended to be the definitive statement of his complete system of philosophy, dealing with everything from cosmology to the nature of human happiness. In this book, Stephen Gaukroger examines the whole system, and reconstructs the last two parts, 'On Living Things' and 'On Man', from Descartes' other writings. He relates the work to the tradition of late Scholastic (...) textbooks which it follows, and also to Descartes' other philosophical writings, and he examines the ways in which Descartes transformed not only the practice of natural philosophy but also our understanding of what it is to be a philosopher. His book is a comprehensive examination of Descartes' complete philosophical system. (shrink)

This chapter considers philosophical problems concerning non-human (and sometimes human) animals, including their metaphysical, physical, and moral status, their origin, what makes them alive, their functional organization, and the basis of their sensitive and cognitive capacities. I proceed by assuming what most of Descartes’s followers and interpreters have held: that Descartes proposed that animals lack sentience, feeling, and genuinely cognitive representations of things. (Some scholars interpret Descartes differently, denying that he excluded sentience, feeling, and representation from animals, and I consider (...) the evidence for these interpretations as well.) Given that Descartes denied any sort of soul to animals, his other philosophical commitments entailed that he must explain the vital and sensitive powers of non-human animals through purely material causes. Indeed, he welcomed this task, for he was engaged in the larger project of providing purely mechanistic explanations for all natural phenomena of the material world. Animal bodies form functional unities that are adapted to environmental circumstances. In his new physics, Descartes sought to discover or hypothesize material mechanisms that would explain the physiological and behavioral capacities of animals, including how they maintain themselves by seeking food and drink, reproduce themselves, and modify their behavior to fit current circumstances. Metaphysically, his new perspective raised the problem of accounting for the functional unity of the animal body considered as a purely material construction, devoid of an active, organizing power such as the sensitive soul. Descartes’s project becomes even more challenging if we ask whence come such mechanisms that are capable of performing the functions of living things. Officially, Descartes endorsed the accepted theological orthodoxy, that God designed and created the bodily mechanisms of humans and animals. However, in his natural philosophy he set himself the task of explaining the origin of animals as part of the natural development of the universe out of an original chaotic soup of material particles. Within this naturalistic perspective, he must explain how, through purely material processes, the functionally organized bodies of living things (plants and animals) could be produced from non-living matter. Without a designing creator, how do animal bodies arise that are capable of digesting food, growing, reproducing, and performing the behaviors needed to preserve life and health? (shrink)