Marleen Rozemond

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.

Donald Rutherford and Jan Cover have put together an excellent volume of essays on Leibniz. Cover and Rutherford begin the volume with a clear and informative introduction, that should serve the less initiated extremely well. They explain the developments of Leibniz scholarship over the course of the twentieth century: the early twentieth century saw a focus on logic, truth and closely connected issues sparked by Russell and Couturat. In the second half of the century the scholarship changed course: issues central to metaphysics and theology became prominent in Leibniz scholarship. Furthermore, in the last 30 years or so, Leibniz scholarship has exemplified a more historical turn in history of philosophy in the English-speaking world. Scholars started to look at the historical background of Leibniz’s thought, and take an interest in the development of Leibniz’s thought over time, and in his very early work, where his thought seems to be quite different from the later, more familiar writings. The present volume exemplifies these newer tendencies.

The Clarke-Collins correspondence was widely read and frequently printed during the 18th century. Its central topic is the question whether matter can think, or be conscious. Samuel Clarke defends the immateriality of the subject of the mental against Anthony Collins’ materialism. This paper examines important assumptions about the nature of body that play a role in their debate. Clarke argued that consciousness requires an “individual being”, an entity with some sort of significant unity as its subject. They agree that body does not have this type of unity, because it consists of actually distinct parts.

Early modern philosophers rejected various important aspects of Aristotelianism. Current scholarship debates the question to what extent the early moderns rejected final causation. Leibniz explicitly endorsed it. I argue that his notion of final causation should be understood in connection with his resurrection of substantial forms and his seeing such forms on the model of the soul. I relate Leibniz’ conception of final causation to the Aristotelian background as well as Descartes’s treatment of teleology. I argue that he agreed with a view found in Aristotelianism that genuine efficiently causal powers require immanent teleology and with Descartes that immanent teleology presupposes cognition in the agent.

The Clarke-Collins correspondence was widely read and frequently printed during the 18th century. Its central topic is the question whether matter can think. Samuel Clarke defends the immateriality of the human soul against Anthony Collins’ materialism. Clarke argues that consciousness must belong to an indivisible entity, and matter is divisible. Collins contends that consciousness could belong to a composite subject by emerging from material qualities that belong to its parts. While many early modern thinkers assumed that this is not possible, this correspondence offers an unusually detailed discussion of this issue. Clarke rejects emergentism because real qualities of a composite must be homogeneous with the qualities of the parts. This rejection is based on considerations about the nature of causation. In addition, the disagreement derives in part from a disagreement between Clarke and Collins about the limits of our knowledge.

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.

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.