This essay explores the vexed issue of individual corporeal substance in Descartes' natural philosophy. Although Descartes' often referred to individual material objects as separate substances, the constraints on his definitions of matter and substance would seem to favor the opposite view; namely, that there exists only one corporeal substance, the plenum. In contrast to this standard interpretation, however, it will be demonstrated that Descartes' hypotheses make a fairly convincing case for the existence of individual material substances; and the key to (...) this new found individuation is a long neglected set of passages in the Principles of 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 the first part of this paper I explore the relations among distinctness, separability, number, and non-identity. I argue that Descartes believes plurality in things themselves arises from distinction, so that things distinct in any of the three ways are not identical. The only exception concerns universals which, considered in things themselves, are identical to particulars. I also argue that to be distinct is to be separable. Things distinct by reason are separable only in thought by means of ideas not (...) clear and distinct. In the second part I argue that the notion of separability in Descartes’s account of real distinction between mind and body is subject to five different interpretations. I claim that the heart of Cartesian dualism concerns the separability of the attributes thought and extension. It does not require that mind and body are separable in the sense that each can exist without the other existing. (shrink)

“Leibniz on Consciousness and Self‐Consciousness” It is argued that Leibniz held a version of the so‐called “higher‐order thought” theory of consciousness. According to this theory, what makes a mental state conscious is that it is accompanied by a thought that one is in that state. For example, in elaborating on his theory of monads, Leibniz explains that an unconscious perception becomes conscious when it is accompanied by an apperception of it. Apperception is best understood as a form of self‐consciousness, and (...) reflection is best understood as a sophisticated form of apperception. With these crucial terminological distinctions in place, it is then argued that treating Leibniz as a HOT theorist can help us understand how he did indeed hold that animals apperceive even if most of them are incapable of sophisticated forms of reflection and rationality. (shrink)

I undertake to examine how Descartes understood the relationship between physics and mathematics. My thesis is that what distinguishes the objects of mathematics from those of physics on Descartes's view is that the former are considered in abstraction from a material substratum while the latter are considered as involving a material substratum. Since it has often been maintained that Descartes identified matter with extension, and hence rejected the notion of a material substratum, I attempt in the first part of my (...) paper to establish the textual basis for ascribing a substratum view to Descartes. In the second part of the paper, I present the case for my thesis concerning Descartes's account of the difference between the objects of mathematics and those of physics. (shrink)

What are Descartes's criteria for substance, and how many material objects meet them? A passage in the Synopsis of the Meditations has led some to portray him as a monist about extended substance and others to say that he does not even use “extended substance” as a count term. After considering Descartes's two criteria for substance, as well as his account of transubstantiation, we see that these answers are mistaken. Descartes countenances an infinity of extended substances. These are quantities of (...) matter that can survive any rearrangement or scattering of their parts, but not the annihilation of any of them. (shrink)

Descartes rightly attacked the idea of space as extended nothing, but in inferring that space is an extended something, a substance, he overlooked the possibility that it is instead a system of relations. Even if it is a substance, it does not follow – as Descartes implied that it does – that “space” and “matter” are synonymous. It might instead be that space is a substantial container, portions of which can be colocated with bodies or that space is a substantial (...) separator, portions of which flow into all locations where there are no bodies. (shrink)