In the _Meditations_ and related texts from the early 1640s, Descartes argues that the self can be correctly considered as either a mind or a human being, and that the self’s properties vary accordingly. For example, the self is simple considered as a mind, whereas the self is composite considered as a human being. Someone might object that it is unclear how merely considering the self in different ways blocks the conclusion that a single subject of predication—the self—is both simple (...) and composite, which is contradictory. In response to this objection, this paper develops a reading of Descartes’s various ways of considering the self. I argue that the best reading of Descartes’s qualified claims about the self, i.e., about the self _qua_ mind or the self qua human being, presupposes an account of the unqualified self, that is, of the self _simpliciter_. I argue that the self _simpliciter_ is not a mind, and that it is not a human being either. This result might suggest the pessimistic conclusion that Descartes’s view of the self is incoherent. To avoid this result, I introduce a new metaphysical account of the Cartesian self. On my view, the self is individuated by a unified mental life. The self is constituted by the beings that jointly produce this mental life, and derives its unity from it. (shrink)

ABSTRACTThis paper studies Antoine Le Grand's account of organic identity over time in human bodies. In response to Aristotelian critics who argued that the Cartesian rejection of the Aristotelian ontology of matter and form had put in jeopardy the diachronic identity of material substances in general and of living bodies in particular, Le Grand argued that the identity over time of the human body could be accounted for without the traditional notions of matter and form. The paper shows how he (...) drew on both the Cartesian metaphysics of mind and body and contemporary views on human anatomy and organic generation to develop a unique account of bodily identity over time in human animals. (shrink)

As the word “optics” was understood from antiquity into and beyond the early modern period, it did not mean simply the physics and geometry of light, but meant the “theory of vision” and included what we should now call physiological and psychological aspects. From antiquity, these aspects were subject to geometrical analysis. Accordingly, the geometry of visual experience has long been an object of investigation. This chapter examines accounts of size and distance perception in antiquity (Euclid and Ptolemy) and the (...) Middle Ages (Ibn al-Haytham), before turning to "natural geometry" in Kepler and Descartes. It finds a purely mechanical realization of natural geometry in Descartes (primarily in his L'Homme, 1664), in which he conceives states of the visual system as varying in accordance with distance, much as his geometrical compasses vary their spatial relations in accordance with geometrical proportions. This reading challenges the notion that a two-dimensional sensation (without three-dimensional phenomenality) was universally accepted prior to the nineteenth century by positing a direct psychophysiological account of the experience of distance in Descartes. It thereby challenges the interpretations of Descartes on natural geometry of George Berkeley, Nancy Maull, Margaret Wilson, Erwin Panofsky, and Jonathan Crary. (shrink)

Descartes analysed the mind into various faculties or powers, including pure intellect, imagination, senses, and will. This article focuses on his account of the sensory power, in relation to its Aristotelian background. Descartes accepted from the Aristotelians that the senses serve to preserve the body by detecting benefits and harms. He rejected the scholastic Aristotelian sensory ontology of resembling species, or ‘forms without matter’. For the visual sense, Descartes offered a mechanistic ontology and a partially mechanized account of sensory processes, (...) including some previously ascribed to judgement. He did this in the context of his theory of brain signs that prompt sensations. The article contends that Descartes’s use of the sign-relation was modelled on standard discussions of non-resembling signs in commentaries on Aristotle’s De interpretatione. It follows three uses of the sign-relation: brain states that cause colour sensations; brain states that cause experiences of spatialized contents, such as shapes; and brain states that realize a ‘natural geometry’. It argues that Descartes’s natural geometry does not involve mental operations but physiological mechanisms that co-vary with the distance to seen objects. While retaining the language of sensory powers, Descartes offered a partial mechanization of those powers. (shrink)

In 1675, Burchard de Volder (1643–1709) was the first professor to introduce the demonstration of experiment into a university physics course and built the Leiden Physics Theatre to accommodate this new pedagogy. When he requested the funds from the university to build the facility, he claimed that the performance of experiments would demonstrate the “truth and certainty” of the postulates of theoretical physics. Such a claim is interesting given de Volder’s lifelong commitment to Cartesian scientia. This chapter will examine de (...) Volder’s views on experiment and show that they are not Newtonian or inductivist, as is sometimes claimed. While de Volder thinks we need deductive reasoning from first principles to provide evidence of the certainty of the content of our physical theories, he also contends that we need experiment to provide evidence of the certainty of the existence of the particular bodies those theories discuss. This approach to experiment is based on a distinction between rational certainty and the certainty of material bodies in the actual world. While this account is deeply influenced by Descartes, it is importantly different than Descartes’ distinction between absolute and moral certainty. De Volder’s “Cartesian Empiricism” is best understood as a continuation and further development of a long tradition of teaching through observation at Leiden. (shrink)