It is supposed to be common knowledge in the history of ideas that one of the few medieval philosophical contributions preserved in modern philosophical thought is the idea that mental phenomena are distinguished from physical phenomena by theirintentionality,their intrinsic directedness toward some object. As is usually the case with such commonplaces about the history of ideas, especially those concerning medieval ideas, this claim is not quite true. Medieval philosophers routinely described ordinary physical phenomena, such as reflections in mirrors or sounds in the air, as exhibiting intentionality, while they described what modern philosophers would take to be typically...

The medieval theory of signification underpinned the theory of truth, which in turn fed into a theory of inference. The theory of signification describes generally how words relate to things and how propositions come to mean what they do. But this general description needs a further account of how a particular occurrence of a word in a particular proposition is related to which things in what way. Only then can one say what has to be the case for the proposition to be true, and so determine how truth is preserved in an inference.

For the medievals in whom I...

It would be anachronistic, at the very least, to attribute to Aquinas a theory of mental language. As historians of philosophy seem to agree, and I will not question, it is only after Aquinas that thinkers elaborated theories of mental language, or of a “language of thought,” with attempts to provide a linguistic (especially semantic and syntactic) analysis of cognition: first within the project of later medieval nominalism, and more recently (and apparently independently) by thinkers in contemporary analytic philosophy (foremost Jerry Fodor).¹

Nonetheless, allowing that we do not find a recognizabletheoryof mental language to Aquinas, I want...

Among scholars of medieval philosophy Henry of Ghent is well known as a critic of the view (defended, for example, by Thomas Aquinas) according to which intellectual cognition requires so-called intelligible species, that is, cognitive devices that precede the act of the intellective power and that are necessary in order to render the intellect capable of exercising its activity.¹ It is also generally recognized that Henry did not always reject these species. Whereas he admitted their existence in the earlier stages of his career, he is said to have later modified his position.² Henry’s attitude toward intelligible species is considered...

Suppose I am thinking about what it is to be a cat. What sort of activity am I engaging in? What is it to think about something? Thomas Aquinas and John Duns Scotus answered this question in two remarkably different ways. Even though Scotus did not develop his theory of thinking in direct opposition to Aquinas, a comparison between their treatments can shed some light on what is distinctive of their respective views on what they called “acts of thinking.”¹

It will be convenient to break down the question “What is it to think about something?” into the following three...

In one corner, Socrates. In the other, on the mat, his cat, Felix. Socrates, of course, thinks (correctly) that Felix the Cat is on the mat. But there’s the rub. For Socrates to think that Felix is on the mat, he has to be able to think about Felix, that is, he has to have some sort of cognitive grasp of an individual—and not just any individual, but Felix himself. How is that possible? What is going on when we think about things?

These questions have a contemporary flavor. First, whether an act of thinking is able to grasp...

William Ockham and John Buridan belong to the same late medieval philosophical tradition. What primarily unites this tradition is a shared metaphysical stance, which can be traced at least up to Thomas Hobbes, and which through Hobbes had a profound influence on British philosophy and also on Leibniz. The most salient feature of this tradition’s metaphysics is, of course, the rejection of universals in extramental reality. According to both Ockham and Buridan, universals exist only in language. All things existing in extramental reality are singular.

By saying that they think universals exist only in language, I mean that they think...

The study of consciousness is without question one of the hottest topics in contemporary philosophy of mind, cognitive psychology, and neuroscience. Among other issues currently being debated are: whether consciousness even exists; if it does exist, then can we explain it or characterize it; and if we can do that, then can we explain or characterize the relation between consciousness, on one hand, and, for example, cognition or intentionality, on the other, and further can we say which of these is a more primitive feature of human mental life. All of this contemporary activity in the study of consciousness has...

Externalism in recent philosophy is the idea that the internal states of an agent do not suffice in general to determine the content of what she thinks, or knows or does not know, or the meaning of what she says. Under one guise or another, externalism has been defended by some of the most prominent analytic philosophers of the last three or four decades, including Hilary Putnam, Saul Kripke, Tyler Burge, Jerry Fodor, Donald Davidson, Ruth Millikan, David Armstrong, and Alvin Goldman. What I would like to show here is that there was already an important externalist drive in William...

Conceiving of the mind as a substance, Adam Wodeham regarded thoughts as accidents within the mind and their contents as fixed independently of things existing outside of it. He also recognized, however, that, in the normal course of nature, our simplest and most basic mental acts, by which we conceive of the nonmental things we form complex thoughts about, are ultimately caused by things existing outside our mind and within our environment. This doctrine is the subject of the present writing, the issue being whether it should be regarded as internalist, as the former feature suggests, or as externalist, as...

Recent scholarship has begun to uncover the nature and extent of the reciprocal—and typically adversarial—relationship between William Ockham (d. 1347) and Walter Chatton (d. 1343). We now know, for example, that Chatton, a slightly younger contemporary of Ockham, is both enormously influenced by and, at the same time, highly critical of his older colleague. Chatton often takes up precisely those questions Ockham treats (and likewise the terminology and conceptual framework in which he expresses them) only to reject Ockham’s conclusions.¹ We also know that Chatton’s criticisms leave their mark on Ockham. Ockham frequently rehearses and responds to Chatton’s objections,...

If we admit that all mental states share a common feature, namely, the feature of being about something, or being directed toward something, then we can describe “intentionality” as this property of aboutness or directedness. But what is this thing that a mental state is about? More precisely, two questions should be answered: What makes a mental state intentional? Why is this mental state aboutthisobject (rather thanthat)? The first question is supposed to explain the ontological status of a mental state, the second, to describe how a mental state can be related to an object. Of course,...

What is intentionality? It is a useful concept, but its essence is hard to define, especially if we look at how it has actually been used by philosophers since Greek and Roman antiquity. It behaves like a quality, though it is not always clear what kind of quality it is or what it is a quality of. Sometimes it is specified as a quality of qualities, a concept of concepts, though we also see it ascribed to things outside the mind, as when Thomas Aquinas uses it to characterize the sensory species transmitted through the medium between object and perceiver.¹...

In hisPhilosophical Investigations(Philosophische Untersuchungen), Ludwig Wittgenstein makes the following remark about animal thinking:

It is sometimes said that animals do not talk because they lack the mental capacity. And this means: “they do not think, and that is why they do not talk.” But—they simply do not talk. Or to put it better: they do not use language—if we except the most primitive forms of language.¹

We should thus be careful not to assume a necessary connection between the use of language and a capacity for thought. In fact, thinking may be an ability not connected...

The short introductory remarks of Aristotle’sDe interpretatione,as unimposing as they may appear, have provided the starting point of some of the most intense and long-lasting debates in the history of semantics and epistemology.¹ Quite a number of these discussions are more or less closely related to the Stagirite’s well-known statement that “mental concepts are the same for all” (eaedem omnibus passiones animae sunt). What at a first glance might appear to be but an arcane issue in the scholastic exegesis of Aristotle, i.e. the attempt to provide a reasonable interpretation and account of his thesis of the inter-subjective...

Talking about mental representations and concepts in medieval philosophy, one should probably start with clarifying these terms in the way medieval philosophers used and understood them. However, the phraserepraesentatio mentalisis rarely, if ever, used by medieval philosophers: “mental representation” is rather a term of art of modern philosophy of mind. Furthermore, although the termconceptusis widely used by medieval philosophers, its meaning and reference seem to vary widely among them, depending on their particular theories. Indeed, to complicate matters, many authors would use other terms, such asintentio, intellectus, notitia,or evenratioorverbum mentis,let...