Marleen Rozemond

This chapter explains Descartes view that the mind, the source of mental states in incorporeal substance. Decartes acts of intellection are not accompanied by correlated physical events but there are physical events that parallel intellection and that intellection is independent of the body because intellection is an operation of the mind alone. This chapter explains Descartes mechanistic explanations as covering all animal behavior as a support to the immortality of the human soul with the human soul as different from the animal soul since human soul is immortal. This chapter also explains that the animal soul dies with the animal but it is thought to have some degree of reason, while the human soul is the principle of all the variety of functions ascribed to humans and the power of intellection. In intellection the soul operates independently of the body. The soul is the form of the body. It is also dependent on the body but at the same time it is an incorporeal body. Further the chapter explains Descartes mechanistic science which means that operations traditionally ascribed to the soul except the intellect can be explained mechanistically and does not need a soul.

Descartes held that the human mind or soul is indivisible, unlike body. In this paper I argue that his treatment of this feature of the soul is intimately connected to his engagement with Aristotelian scholasticism. I discuss two strands in Descartes. There is a long tradition of arguing for the immortality of the human soul on the basis of this view. Descartes did use this view in defense of dualism, but I argue that he held that the soul’s immortality should be established rather on the basis of its status as a substance. This line of thought, I contend, is connected to his rejection of (most) Aristotelian substantial forms. Furthermore, the indivisibility of the human soul emerges repeatedly in connection to the union and interaction of mind and body in ways that connect to Aristotelian scholastic treatments of these issues.

Locke claimed that God superadded various powers to matter, including motion, the perfections of peach trees and elephants, gravity, and that he could superadd thought. Various interpreters have discussed the question whether Locke's claims about superaddition are in tension with his commitment to mechanistic explanation. This literature assumes that for Locke mechanistic explanation involves deducibility. We argue that this is an inaccurate interpretation and that mechanistic explanation involves a different type of intelligibility for Locke.

Descartes, an acknowledged founder of modern philosophy, is identified particularly with mind-body dualism--the view that the mind is an incorporeal entity. But this view was not entirely original with Descartes, and in fact to a significant extent it was widely accepted by the Aristotelian scholastics who preceded him, although they entertained a different conception of the nature of mind, body, and the relationship between them. In her first book, Marleen Rozemond explicates Descartes's aim to provide a metaphysics that would accommodate mechanistic science and supplant scholasticism. Her approach includes discussion of central differences from and similarities to the scholastics and how these discriminations affected Descartes's defense of the incorporeity of the mind and the mechanistic conception of body. Confronting the question of how, in his view, mind and body are united, she examines his defense of this union on the basis of sensation. In the course of her argument, she focuses on a few of the scholastics to whom Descartes referred in his own writings: Thomas Aquinas, Francisco Suarez, Eustachius of St. Paul, and the Jesuits of Coimbra. This new systematic account of Descartes's dualism amply demonstrates why he still deserves serious study and respect for his extraordinary philosophical achievements.

In recent years more and more scholars of early modern philosophy have come to acknowledge that our understanding of Descartes’s thought benefits greatly from consideration of his intellectual background. Research in this direction has taken off, but much work remains to be done. Dennis Des Chene offers a major contribution to this enterprise. This erudite book is the result of a very impressive body of research into a number of late Aristotelian scholastics, some fairly well known, such as Suárez, others quite obscure. Two thirds of the book is devoted to the Aristotelians, with occasional references to Descartes; the last third focuses on Descartes, although there still much Aristotelian ground is covered. Des Chene indicates three major themes for his book: natural change and agency, the structure of material substance, and finality.

A prominent argument for the immateriality of the soul is the so-called "Achilles Argument", which relies on the claim that the soul is simple or indivisible. It was not widely used in the Aristotelian tradition, however. But a version of the argument played a crucial role in Suárez’s contention that a human being contains only one unitary soul. On an alternative view that was widespread at the time, living substances may contain several souls, such as a sensitive and a rational soul in the case of human beings. Suárez holds that the powers of the soul are really distinct from each other and from the soul itself. At the same time, the actions of the different powers of the soul influence each other, as when a loud noise distracts me from doing philosophy or when my intellect relies on my imagination for mental images. Suárez argues that this interaction between powers requires that they are all are "rooted" [radicatae] in one single soul.

In the Monadology Leibniz has us imagine a thinking machine the size of a mill in order to show that matter can’t think, or, in his terms, cannot have perceptions: his well-known Mill Argument. The argument is often thought to rely on the unity of consciousness and the notion of simplicity. Leibniz himself did not see matters this way. For him the argument relies on the Cartesian “Mode-Nature View”, and the idea that perception is not a modification of matter because perception is active and matter is passive. At the same time, there are traces in Leibniz of a different argument that relies on the idea that perception is an “internal” action, an action of a thing on itself as opposed to an “external” action, where a thing acts on a different thing.

In Descartes's Method of Doubt Janet Broughton examines in depth Descartes's well-known use of the method of doubt in the Meditations. This is a very stimulating book. The book is rich in subtle, interesting ideas, and the writing is engaging in perhaps the best sense for philosophy. It is not only extremely lucid, but in addition one senses Broughton think the issues through on the page in a way that strongly draws the reader in. Broughton pursues the historian's aim of offering an interpretation of Descartes's method of doubt that accounts for the texts. She does so while pursuing the issues with philosophical intensity and depth and connecting her interpretation to contemporary investigations in skepticism. Her evaluation of Descartes's use of the method is mixed: she thinks his ambitions in using it are ‘splendid but doomed, and highly instructive’. After describing the contents of the chapters of the book, I will focus on two issues: Broughton's interpretation of Descartes's anti-skeptical strategy and her treatment of transparency of the mental.

Descartes's dualism, and his argument for it, are often understood in terms of the modal notion of separability. I argue that the central notions, substance and real distinction, should not be understood this way. Descartes's well-known argument for dualism relies implicitly on views he spells out in the Principles of Philosophy, where he explains that a substance has a nature that consists in a single attribute, and all its qualities are modes of that nature. The argument relies ultimately on a deeply rationalistic view of substance.

In this paper I explain several ways in which Descartes denied that the human soul or mind is composite and the role this idea played in his thought. The mind is whole in the whole and whole in the parts of the body because it has no parts. Unlike body, the mind is indivisible, and this is a different idea from the thought that mind and body are incorruptible. Descartes connects the immortality of the soul with its status as a substance and as incorruptible rather than with its indivisibility.

Descartes argued that the eternal truths, most prominently the truths of mathematics, are created by God. He was not explicit, however, about the ontological status of these truths. Interpreters have proposed interpretations ranging from Platonism and conceptualism. I argue for an intermediate interpretation: Descartes held they have objective being in God’s mind. In this regard his view was line with a prominent view in Aristotelian scholasticism. I defend this interpretation against objections based on divine simplicity and concerns about causation. I raise questions about the philosophical merit of these objections, but in addition I argue that there is good reason to think that Descartes himself did not think they were problems for the view. Seemingly conceptualist passages in the Principles, I argue, in fact address issues different from the ontological status of the eternal truths.