There is broad agreement in the medieval tradition that we conceive things in the world owing to the transmission of intelligible content through various media that culminates in the concept by which something in the world is cognitively present for us. Yet how the intelligible content is transmitted along with the nature of the ultimate object of cognition provoked ceaseless debate. The first three essays in Universal Representation, and the Ontology of Individuation consider these issues as they play out in the metaphysics and natural philosophy of Avicenna, Averroes, Thomas Aquinas, Ockham and others. The last three essays turn to the metaphysical problem of the nature of the principle of individuation. Moderate realists believe in the existence of immanent general natures such as humanity and equinity, whereby individuals are members of diverse natural kinds. Accordingly, moderate realists such as Aquinas, Henry of Ghent and Duns Scotus need to investigate the nature of the individuating principle by which members of one and the same natural kind differ from one another. Nominalists, for their part, need not concern themselves with any principle of individuation as, for them, all reality is individual, there being no immanent universals; but this release comes at the cost of a new set of epistemological problems.

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 their intentionality, their 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 mental phenomena, such as sensation and imagination, as ordinary physical processes. Still, it is true that medieval philosophers would regard all acts of cognition as characterized by intentionality, on account of which all these acts are some sort of representations of their intended objects. Mental Representation explores the intricacies and varieties of the conceptual relationships between intentionality, cognition and mental representation as conceived by some of the greatest medieval philosophers. The clarification of these conceptual connections sheds new light not only on the intriguing historical relationships between medieval and modern thought on these issues, but also on some fundamental questions in the philosophy of mind as it is conceived today.

This volume considers the contemporary relevance of Aquinas’ thought and what parameters should influence its reception. It discusses the reception of Aquinas on creation ex nihilo and offers guidelines for reception in the fields of metaphysics and natural theology. Chapters on physics and philosophy of mind intersect with key modern debates. Contributions interpret Aquinas’ physics in light of contemporary findings and discuss his account of human self-awareness.

This volume considers the Aristotelian virtue-ethics tradition as it develops in the writings of Thomas Aquinas. Part One studies the types of virtues Aquinas believes are held by Christians in a state of grace. Aquinas’s intriguing account is apparently fraught with inconsistencies, which have split contemporary interpreters over not only how to understand Aquinas on this matter, but also as to whether it is even possible to provide a consistent interpretation of his doctrine. This book brings together scholarship that reflects the various sides of the debate. Part Two explores a Thomistic synthesis regarding Aquinas’s account of the good as telos or end that emerges in the seventeenth century, as well as what promise his virtue ethics holds today, arguing that Aquinas’ hylomorphic understanding of human beings as matter-form composites furnishes a robust moral accounting that seems unavailable to alternative, reductive materialist accounts.

Moses Maimonides and John Duns Scotus are key figures as regards the thirteenth-century philosophical tradition that developed out of the Western Christian reception of the Neo-Platonized Aristotelianism of Islamic and Jewish thinkers. Whereas the writings of Maimonides count among the received works that inaugurate and shape this span, the variety of conceptual instruments developed by Scotus arguably signal its end, preparing the way for the emergence of diverse fourteenth-century philosophical worldviews. Maimonides on God and Duns Scotus on Logic and Metaphysics explores the eponymous thinkers’ work across a variety of fields. In the domain of natural theology, Maimonides presses for creation de novo, adapting from the Islamic Kalām tradition what has come to be known as the Argument from Particularity, which deduces intelligent design when science seems, in principle, unable to account for states of affairs that conceivably needn’t obtain (to take an example from modern physics, the strength of the four fundamental forces). Part one of this volume contrasts Maimonides’s and Aquinas’s parallel treatments of this and other proof strategies still employed by contemporary philosophers. Part two, on Scotus, includes discussion of the authenticity of the logical writings attributed to him, the evolution of his thought in this field against the backdrop of various thirteenth-century developments, the types of Aristotelian universals theorized by Scotus, his semantics of theological discourse and ontology of possible entities.

Metaphysical Themes, Medieval and Modern presents three sets of essays that engage the metaphysics of substance through a study of thought on this theme over the last eight centuries, shedding light on contemporary disputes as well as the history of thought leading into the modern era. Part I grows out of an author-meets-critics panel on Robert Pasnau’s Metaphysical Themes: 1274–1671 (OUP, 2011). Pasnau’s rich study delves into the four centuries wherein later medieval thought gives way to the modern period. Andrew Arlig reflects on Pasnau’s discussion of holenmers, entities such as God and the human soul, that are thought to exist as wholes in more or less disparate things. Paul Symington, on the other hand, treats the substance ontology of Thomas Aquinas in particular through a reflection on Aquinas’s understanding of the ontological status of the various modes or accidents of Aristotelian substances. Part II, “Substance Ontology, Medieval and Modern”, transitions to contemporary substance ontology. Travis Dumsday canvasses the field of debate over what is the substratum of change, contending that the Aristotelian, hylomorphic account of substance that views substances as matter-form composites remains the most robust. Gyula Klima, while agreeing with Dumsday’s conclusion, strengthens his argument with reference to the development of this bundle of problems within the recent history of analytic philosophy. Dumsday concludes with reflections on the relevance of substance ontology to natural theology, which, in turn, is the theme of Part III, “The Natural Theology of Thomas Aquinas”, wherein Alexander Hall and Michael Sirilla consider how Aquinas’s understanding of the divine substance bears on the logic of demonstration in his natural theology, concluding that contemporary Radical Orthodoxy readings that have Aquinas forfeit demonstrative proof that God exists misconstrue him on this point.

Skepticism, Causality and Skepticism about Causality studies the interrelated themes of causality and skepticism in contemporary, early modern and medieval philosophy. Thomas Aquinas’s celebrated proofs of the existence of God (the Five Ways of the Summa Theologica) rely in part on an Aristotelian notion of synchronous causality, wherein the things that exist and persist require an accounting that ultimately terminates in the ongoing activity of a first mover, as the existence and persistence of an ecosystem is traceable to the sun. By contrast, in David Hume’s early modern account, causality consists in the regularity of successive events (a rolling billiard ball’s collision with a stationary one is always followed by the movement of the latter). Moreover, Newtonian and Einsteinian accounts respectively suggest that motion, once initiated, requires no explanation. In light of these developments, the first set of essays in this volume re-evaluates the Aristotelian paradigm and its relation to modern science, contending that in some fields (such as ecology, thermodynamics or information theory) contemporary science still preserves some intuitions about causality that support Aquinas’s deliberations. Hume’s skepticism about causality is heir to late medieval and early modern development that transformed not only the notion of causality in general, but also the idea of the causal connections between our cognitive faculties, God, and the world in particular, giving rise to extreme, solipsistic forms of skepticism, such as Descartes’ Demon skepticism. The second set of essays considers whether Aquinas’s thought would be susceptible in some ways to this form of skepticism, and what motivated, just a couple of generations later, the turn to epistemology already involving this sort of skepticism.