Descartes and the Ontology of Everyday Life

Descartes offers a view of the material world that identifies matter with indefinitely divisible extension. Such a view also eliminates the various substantial forms that, for his Scholastic contemporaries, serve to distinguish the natural substances of our experience, the paradigmatic instances of which are living things. These contemporaries countered that this view presents the world as a barren desert landscape, devoid of the variety of everyday life. A further Scholastic objection has it that Descartes’s elimination of substantial forms requires the elimination of a notion of goal-directed functions that is itself required for an understanding of life. From a Scholastic perspective, then, Descartes’s landscape is lifeless as well as barren.In their historically erudite and philosophically stimulating book, Deborah Brown and Calvin Normore argue that Descartes’s account of the material world in fact allows “for distinguishing many different kinds of things, among which we include everyday objects along with substances and modes of his official metaphysics” (3). Thus, they claim to find a basis in Descartes for an “ontology of everyday life.” Moreover, they contend that Descartes has the resources to explain the functional interdependence and unity of organic systems without appealing to a Scholastic notion of final causality that he himself rejected.Let us start with the argument that Descartes allows for an ontology of everyday life. Brown and Normore concede initially that this ontology has no room for the naturally generated and corrupted material substances of the Scholastics. They emphasize here Descartes’s claim in the Synopsis of the Meditations that since “body in general” is a substance, it must be incorruptible (CSM 2:10). 1 Brown and Normore conclude—correctly, I think—that this claim commits Descartes to the conclusion that it is not plants and animals that are substances, but only the parts of extension (the “bodies in general”) of which they are composed. Nonetheless, they also conclude that Descartes can allow that such objects have a distinctive ontological status in virtue of the fact that they have their own “true and immutable nature.” Such a nature serves to distinguish the object from the material substances that compose them. As Brown and Normore express the point, the possession of such a nature is “sufficient to make an ordinary thing an ens per se and unum per se even if it cannot be reduced to any substance that happens to compose it at any given time” (51).This is an ingenious suggestion. That it has a basis in Descartes’s texts, I doubt. For one thing, when Descartes discusses true and immutable natures, it is invariably with respect to our innate ideas of the most basic features of reality. Thus, when providing examples of innate ideas in correspondence, he cites “the idea of God, mind, body, triangle, and in general all those which represent true, immutable and eternal essences” (CSMK 183). In this same passage, he notably offers the astronomical idea of the sun—an ordinary object if there ever was one—as an example of a constructed or “factitious” rather than an innate idea. Moreover, in another text Descartes explicitly distinguishes true and immutable essences from the essences of lions and horses, which “are not transparently clear to us” (CSM 2:84). Though Descartes does not explain what is less than transparent, he seems to have in mind the fact that we cannot derive from the structure of extension alone essential truths concerning lions and horses in the way in which we can so derive from this structure essential truths concerning triangles. There is some reason to think, then, that Brown and Normore overextend Descartes’s notion of true and immutable natures in applying it to justify the claim that ordinary objects constitute entia per se.Brown and Normore also appeal to Descartes’s notion of true and immutable natures to allow for a kind of normativity in our talk of ordinary objects. They suggest on Descartes’s behalf that “relative to the true and immutable nature, horse, Bucephalus is a better instance than Dobbin—better at the things that define that true and immutable nature” (132). I have already questioned whether Descartes allows that there is a true and immutable nature of a horse. However, in this case there is an additional worry that derives from Descartes’s discussion in the Sixth Meditation of the case of a human body suffering from dropsy. Descartes notes that when the human body is considered merely as an extended thing, it is simply a mechanism that follows the laws of nature. It is such a mechanism whether or not it suffers from dropsy, just as a clock is a mechanism that follows these laws whether or not it tells time correctly. When we say that the dropsical body or broken clock deviate from their nature, Descartes insists that this sort of nature is “nothing other than a denomination depending on my thought” and “extrinsic to the things of which it is said” (CSM 2:58–59). So also, it seems, Bucephalus can be said to perform better than Dobbin only with respect to a nature that is extrinsic to the animals themselves. Considered simply as mechanisms operating in accord with the laws of nature, both are performing just as their intrinsic natures require.But does Descartes even have the resources to conceive of an animal body as a distinctive object that retains its identity through changes in its material composition? Brown and Normore claim that he does, appealing to the result in Descartes’s physiological writings that “the heart, brain, lungs, etc. form in sequence and in a way that is mutually reinforcing and sustaining” (127). The development of an organism thus involves “relations of reciprocal dependence” (127), and the persistence of these relations carries with it the persistence of a unified organism. Moreover, though the various parts of an organic body can be said to have “functions” that serve for the preservation of the organism, these do not involve any “ends” set for the organism by God or nature. Thus, Descartes’s prohibition of the appeal to ends in explanations of material nature is upheld.Again, the suggestion here is ingenious. However, I do have the worry that there remains some tacit reliance on a nature that is extrinsic to the purely material objects under consideration. My worry derives from an important passage from a letter to Mesland that Brown and Normore themselves cite at length (see 41–43). There Descartes distinguishes a “body in general” from the human body. Though the former cannot survive any change in its material composition, the latter is able to survive such changes due to its union over time with the same human mind. The human body therefore can remain the same body insofar as “it has in itself all of the dispositions required to preserve that union” with the mind (CSMK 243). It is the union that renders the preservation of these dispositions salient. But the worry here is that the preservation of relations of reciprocal dependence is salient in the case of the nonhuman animal body only when this body is compared to the human body as united to a human mind. We might seem to have the troubling result that the privileging of relations of reciprocal dependence on the basis of the fact that these bring about the continuing preservation of the nonhuman animal itself relies on a comparison to something that is extrinsic to the nature of that animal, namely, the idea of mind-body union.Toward the end of their book, Brown and Normore attempt to “make metaphysical sense” of Descartes’s own account of the union (167). They argue—convincingly, it seems to me—that the mind-body union Descartes posits cannot constitute a single substance. This union thus differs from the substantial union of the Scholastics, which typically is supposed to result in such a substance. But if we cannot conceive of Descartes’s union in terms of a Scholastic substantial union, how can we conceive of it? Brown and Normore claim in response that Descartes’s union is “a paradigm example of how a composite can constitute an irreducible or true and immutable nature” (165). What marks the human composite out as a distinctive kind of nonsubstantial object is the fact that—as in the case of other ordinary objects—it has its own true and immutable nature.Though I cannot completely accept this response, I do agree that Descartes takes the union to involve a special kind of “nature” distinct from the true and immutable natures of mind and body. Recall again the discussion of the dropsical body in the Sixth Meditation. As I have emphasized, Descartes holds the nature involved in our conception of a malfunctioning body is extrinsic insofar as that body is conceived as a mere mechanism. However, in this same passage he notes that when the human body is considered as part of the human composite, we can take it to deviate from a nature that is “something which is really to be found in the things themselves” (CSM 2:59). In holding that the union offers a paradigmatic example, however, Brown and Normore mean to indicate that it serves as only one among other examples of nonsubstantial objects that count as unities. Yet Descartes’s mind-body union seems to constitute a unique sort of case for him, and not one that he can extend (except in a merely extrinsic manner) to the case of ordinary material objects. Moreover, with respect to the claim that the union involves a “true and immutable nature,” it is not clear that Descartes allows that we have an innate idea of the union akin to our innate ideas of the true and immutable essences pertaining to God, mind, and body.The limits of this review preclude me from covering adequately all of the issues raised in this rich book. For instance, Brown and Normore offer on Descartes’s behalf criteria for being an automaton. They also argue cogently against various proposals for what Descartes takes life to be, concluding that “‘life’ as a concept, for Descartes, is equivocal or vague” (167). Finally, in an exploratory final chapter, they go beyond Descartes’s own explicit position in proposing an account of how social and political unions constitute distinctive communal wholes that involve reciprocal dependence among their members. The book in fact provides much material for reflection throughout. To be sure, I have been skeptical of some of the central theses in the book. Yet even where I have disagreed with Brown and Normore, I have learned from engaging with their highly original treatment of Descartes. Let the debate over this treatment begin!Thanks to Deb Brown, Calvin Normore, and Gideon Manning for helpful comments on an earlier draft of this review

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