Peter Hartman

Once Socrates has thought something, he comes to acquire an item such that he is then able to think such thoughts again when he wants, and he can, all other things being equal, do this with more ease than he could before. This item that he comes to acquire medieval philosophers called a cognitive habit which most medieval philosophers maintained was a new quality added to Socrates' intellect. However, some disagreed. In this paper, I will examine an interesting alternative theory put forward by Durand of Saint-Pourçain and Prosper de Reggio Emilia about the location of cognitive habits. On their view, cognitive habits are not to be located in the intellect but in something on the side of the body or sensitive soul.

According to a standard interpretation of Aristotle, a material substance, like a dog, is a hylomorphic composite of matter and form, its “essential” parts. Is such a composite some thing in addition to its essential parts as united? The moderate reductionist says “no,” whereas the anti-reductionist says “yes.” In this paper, I will clarify and defend Durand of St.-Pourçain’s surprisingly influential version of moderate reductionism, according to which hylomorphic composites are nothing over and above their essential parts and the union of those parts, where this union is explained by the presence of two modes: a mode of inherence on the side of form and a mode of substanding on the side of matter.

What is an occurrent mental state? According to a common scholastic answer such a state is at least in part a quality of the mind. When I newly think about a machiatto, say, my mind acquires a new quality. However, according to a view discussed by John Buridan (who rejects it) and John of Mirecourt (who is condemned in 1347 for considering it “plausible”), an occurrent mental state is not even in part a quality. After sketching some of the history of this position, I will present two common arguments against it—the argument from change and the argument from agency. I will then turn to Mirecourt’s own position on the matter. Mirecourt, I show, in fact offers us two different theories about occurrent mental states. The first, which I call the conservation theory, accepts that mental states are in part qualities. However, a mental state is a quality together with an action on the side of the mind, namely, its conservation of a quality within itself. The second position, which I will call the pure-action theory, holds that an occurrent mental state is not even in part a quality; instead, it is an action the mind performs which is neither the production nor the conservation of a quality within itself. Mirecourt characterizes such pure actions as “modes” of the mind, and it is this position which is condemned in 1347. In the final section, I turn to an objection that both Buridan and Mirecourt raise against the pure-action theory: if accidental states of the mind are mere modes of the mind, then why not suppose that all accidents are mere modes of the subjects which they qualify?

This book provides the Latin text and its annotated English translation of the question-commentary of John Buridan (ca. 1300-1360) on Aristotle’s “On the Soul”. Buridan was the most influential Parisian nominalist philosopher of his time. His work speaks across centuries to our modern concerns in the philosophy of mind. This volume completes the project of a volume published earlier in the same series: “Questions on the Soul by John Buridan and Others”. An appealing book for scholars of Aristotle and those who are in the field of Medieval philosophy.

When I think that I am now thinking about a rose, are there two mental acts present in the intellect at once, the one direct (about the rose) and the other reflex (about the thought about the rose)? According to a generally accepted principle in medieval psychology, a given mental power cannot have or elicit multiple mental acts at the same time. Hence, many medieval thinkers were unwilling to admit that during such a case of mental reflection there are two acts present in the mind. In this paper, I will look at two theories about mental reflection. According to John Pouilly (1312), during a case of mental reflection there is just one act present in the mind. However, this one act is somehow identical with the direct mental act about the rose that immediately preceded it. If it were not identical with this act, then the sentence "I am thinking that I am thinking about a rose" would be false, since in order for this sentence to be true the direct mental act of thinking about the rose must be present with the reflex mental act of thinking about that act, either as a distinct act, or as somehow identical with it. According to John Baconthorpe (ca. 1325), such a view fails, for even if the reflex mental act were somehow identical with the direct mental act that immediately preceded it, still we would have to admit that it does not coexist with it. On his view, what is sufficient here is that the direct mental· act exist merely as a kind of represented object. Hence, for Baconthorpe, when I think that I am thinking about a rose, there is just one act present in the mind, and this one act has as its content another distinct act (the direct act). However, the direct act does not really exist at the same time as it, although it is represented as if it did.

The relation-theory of mental acts proposes that a mental act is a kind of relative entity founded upon the mind and directed at the object of perception or thought. While most medieval philosophers recognized that there is something importantly relational about thought, they nevertheless rejected the view that mental acts are wholly relations. Rather, the dominant view was that a mental act is either in whole or part an Aristotelian quality added to the mind upon which such a relation to the object can be founded. In this paper, I examine Durand of St.-Pourçain's defense of the relation-theory of mental acts against two objections raised against it: the first from John Duns Scotus, among others, and the second from an anonymous Thomist and Adam Wodeham.

Early modern philosophers, such as Descartes and Spinoza, appeal to a theory of modes in their metaphysics. Recent commentators have argued that such a theory of modes has Francesco Suárez as its primary source. In this paper, I explore one explicit source for Suárez’s view: Durand of St.-Pourçain, an early fourteenth-century philosopher. My aim will be mainly expository: I will put forward Durand’s theory of modes, thus correcting the persistent belief that there was no well-defined theory of modes prior to Suárez. First, I will sketch out the historical and theological context in which Durand developed his theory, briefly canvassing some of the items that he treats as modes as well. Second, I will go over the distinctive features that Durand thinks modes have. Finally, I will close with some reflection on why we should countenance modes in our ontology. Along the way, I will correct a few misconceptions about Durand’s theory of modes.