Links go to abstracts of books, except in the case of the book reviews, where I supply the full text.
The Philosophy of Aquinas (Boulder: Westview Press, 2003). Coauthored with Christopher Shields.
Cambridge Translations of Medieval Philosophical Texts. Volume III: Mind and Knowledge (Cambridge: Cambridge University Press, 2002).
Thomas Aquinas on Human Nature. A Philosophical Study of Summa theologiae 1a 75-89 (Cambridge: Cambridge University Press, 2002).
Thomas Aquinas, Treatise on Human Nature (Summa theologiae 1a 75-89) (Indianapolis: Hackett, 2002).
Thomas Aquinas, Commentary on Aristotle's De anima, translation with introduction and notes (New Haven: Yale University Press, 1999).
Theories of Cognition in the Later Middle Ages (Cambridge: Cambridge University Press, 1997).
"The Event of Color," Philosophical Studies (forthcoming).
I argue that there is another, hitherto unnoticed way of thinking about color: that colors are not standing properties or dispositions of objects, but events that take place when a surface is illuminated by light. If physicalism about color is true at all, this is its most defensible form.
“Id Quo Cognoscimus,” in H. Lagerlund and P. Kärkkäinen (eds.) Theories of Perception in Medieval and Early Modern Thought (Aldershot: Ashgate, 2008).
Aquinas holds that the mental likeness or "species" in cognition is "that by which we cognize" rather than the thing itself that is cognized. In my Theories of Cognition monograph I claimed that, surprisingly, Aquinas is committed to treating the species as in fact the object of cognition in a certain sense. Here I reaffirm that conclusion, responding to some critics along the way, by considering the ontological status of species as accidents of the soul.
“The Mind-Soul Problem,” in H. Thijssen (ed.) Mind, Perception, and Cognition (Aldershot: Ashgate, 2008).
Whereas we now think of dualism as plagued principally by the difficulty of explaining the mind's union and interaction with the body (the mind-body problem), I argue that medieval versions of dualism are best seen as facing a rather different problem, that of explaining the relationship between soul and mind (the mind-soul problem). Some scholastic authors, such as Aquinas, distinguish between the soul and its powers, which helps them explain how the soul can both be the form of the body and give rise to mental phenomena. Other authors, such as Ockham, identify the soul with its powers. Each view poses problems of its own, and these issues anticipate various issues that would become central in the seventeenth century.
"Democritus on Secondary Qualities," Archiv für Geschichte der Philosophie 89 (2007) 99-121.
Democritus is customarily described as having drawn the distinction betwen primary and secondary qualities that would become famous in John Locke. I argue that this is not so, and that Democritus is better viewed as an anti-realist regarding all sensible qualities, primary and secondary. Just how far his anti-realism extends is a difficult question, which I attempt to address.
“Mind and Extension (Descartes, Hobbes, More),” in H. Lagerlund and O. Pluta (eds.) Forming the Mind (Dordrecht: Springer, 2007).
Descartes, Hobbes, and More form an interesting philosopher's triangle, agreeing and disagreeing in overlapping ways regarding whether the mind is extended and whether it is incorporeal. Their agreements and disagreements raise some fundamental questions regarding how to understand what demarcates the distinction between the material and immaterial realms.
“Aquinas on Abstract Truth,” in H. Lagerlund (ed.), Representation and Objects of Thought in Medieval Philosophy (Aldershot: Ashgate, 2007) 33-63.
Thomas Aquinas holds that the proper objects of intellect are the natures of material objects, conceived of universally through intellectual abstraction. This paper considers two questions regarding that doctrine: first, what are these abstracted, universal objects and second, given that the world is concrete and particular, how can such abstract, universal thoughts yield true beliefs about the world?
“A Theory of Secondary Qualities,” Philosophy and Phenomenological Research 73 (2006) 568-91.
The secondary qualities are those qualities of objects that bear a certain relation to our sensory powers: roughly, they are those qualities that we can readily detect only through a certain distinctive phenomenal experience. Contrary to what is sometimes supposed, there is nothing about the world itself (independent of our minds) that determines the distinction between primary and secondary qualities. Instead, a theory of the secondary qualities must be grounded in facts about how we conceive of these qualities, and ultimately in facts about human perception.
“Form, Substance, and Mechanism,” Philosophical Review 113 (2004) 31-88.
The scholastic doctrine of substantial form is two-sided, at times appearing concrete and causal, and at other times abstract and metaphysical. Both sides of the theory serve to explain the special sort of unity possessed by substances, but in later medieval thought the concrete side seems ascendant. Turning to the seventeenth century, the paper first considering several gross misunderstandings of the theory, and then evaluates the extent to which substantial forms can be seen to have survived in the work of Descartes, Boyle, and Locke. Contrary to some recent suggestions, Descartes accepts virtually nothing of the doctrine. Boyle and especially Locke, however, can be read as accepting large portions of the doctrine, albeit within a mechanistic framework.
“Human Nature” in A. S. McGrade (ed.) The Cambridge Companion to Medieval Philosophy (Cambridge University Press, 2003), 208-30.
A very fast summary of medieval thought on mind, knowledge, free will, immortality, and the mind-body problem, extending from Augustine into the later Middle Ages.
“Souls and the Beginning of Life (A Reply to Haldane and Lee),” Philosophy 78 (2003) 509-19.
My monograph Thomas Aquinas on Human Nature attempts to use Aquinas's metaphysics to defend a moderate view on the ethics of abortion: that an abortion at any time during a pregnancy should be considered a grave loss, but that it should be considered murder only after roughly the middle of the second trimester. John Haldane and Patrick Lee contend that I have misunderstood the implications of Aquinas's view, and that in fact his metaphysics supports the conclusion that a human being comes into existence at the moment of conception. Here I make a brief reply.
“Cognition,” in T. Williams (ed.) The Cambridge Companion to Duns Scotus (Cambridge University Press, 2003), 285-311.
A summary of John Duns Scotus's theories of sensory and intellectual cognition, mental representation, intentionality, intuitive cognition, and divine illumination.
“What is Cognition? A Reply to Some Critics,” American Catholic Philosophical Quarterly 76 (2002) 483-90.
In my Theories of Cognition monograph, I proposed understanding Aquinas's theory of cognition in terms of the possession of information about the world. This proposal has seemed problematic in various ways. It has been said to include too much, and too little, and to be the wrong sort of account altogether. Nevertheless, I continue to think of it as the most plausible interpretation of Aquinas's theory.
“Final Causes and Intentionality,” in D. Perler (ed.) Intentionality in Ancient and Medieval Philosophy (Brill, 2001) 301-23.
"Plotting Augustine's Confessions," Logos: A Journal of Catholic Thought and Culture 3 (2000) 77-106.
Originally intended as a guide to teaching the Confessions in the setting of an introductory philosophy class. (It was nevertheless rejected by Teaching Philosophy on the grounds that it did not talk about teaching philosophy.) The above link goes to a full-text version of the paper (with permission from the editors at Logos).
"Sensible Qualities: The Case of Sound" Journal of the History of Philosophy 38 (2000) 27-40.
Medieval theories of perception rest on the sensible qualities that are the objects of perception. In the Aristotelian tradition, the different kinds of perception and the different sensory modalities are defined in terms of these objects. One of the most interesting cases is that of sound, for two reasons. First, the medievals (unlike us) standardly took sound to be an irreducible quality. But since it was obvious that sound is tightly linked with motion, questions arose over whether sound might in the end just be a certain kind of motion and, therefore, not a sensible quality at all. Second, the medievals (like us) standardly supposed that sounds are located in the surrounding medium. But this raised difficulties for their wider theory of perception, leading to questions of whether sounds should instead be located at their point of origin.
"Divine Illumination" in The Stanford Encyclopedia of Philosophy (orig. vers. November 2, 1999).
"Peter John Olivi" in The Stanford Encyclopedia of Philosophy (orig. vers. November 2, 1999).
"What is Sound?" Philosophical Quarterly 49 (1999) 309-24.
Our standard view about sound is incoherent. On one hand we suppose that sound is a quality not of the object that makes the sound, but of the surrounding medium. This is the supposition of our ordinary language, modern science, and a long philosophical tradition. On the other hand, we suppose that sound is the object of hearing. This, too, is the assumption of ordinary language, modern science, and a long philosophical tradition. Yet these two assumptions cannot both be right--not unless we wish to concede that hearing is illusory and that we do not listen to the objects that make sounds. To avoid these consequences we must recognize and repair the inconsistencies contained in our standard view of what sound is. I offer an account that ascribes sound as a quality belonging not to the medium, but to the object that makes the sound.
"Olivi on Human Freedom" in Pierre De Jean Olivi (1248-1298) (Paris: Vrin, 1999) 15-25.
"Aquinas and the Content Fallacy," Modern Schoolman 75 (1998) 293-314.
The content fallacy is my name for the mistake in reasoning that comes from conflating two kinds of facts: facts about the content of our thoughts, and facts about what shape or form our thoughts take in our mind. This mistake appears throughout Thomas Aquinas's philosophical work, in many different contexts: it shapes his account of agent intellect; it grounds his insistence that intellect has no direct apprehension of singular material objects; it provides a principal argument for the human soul's immateriality and incorruptibility. {Addendum of December 2008: When I published this paper, I expected there to be someone out there who could show me how to defend Aquinas against this seemingly devastating objection. It was when I realized there was no one out there who could do this that my philosophical adolescence was over.}
"Aquinas on Thought's Linguistic Nature," Monist 80 (1997) 558-75.
Thomas Aquinas gives us many reasons to think that conceptual thought is linguistic in nature. But how exactly should we understand the apparent connection between thought and language? This paper focuses on two respects in which thought is language-like, each of which finds some support in Aquinas's work. One is the claim that the content of our thought is in some way linguistic. The second is the claim that thoughts are structurally linguistic, that there is a language of thought. Although Aquinas defends this latter claim, he does not go as far as William Ockham later would.
"Olivi on the Metaphysics of Soul," Medieval Philosophy and Theology 6 (1997) 109-32.
"Petri Iohannis Olivi Tractatus de verbo" in Essays in Honor of Fr. Gedeon Gál (St. Bonaventure, NY: Franciscan Institute Press, 1997). [Franciscan Studies 53 (1993) 121-53].
An edition of the beginning of Olivi's commentary on the Gospel of John, where he discusses at length his theory of the mental word (verbum). In an extended introduction to the text, I analyze the philosophical significance of Olivi's account for the philosophy of mind.
"Who Needs an Answer to Skepticism?" American Philosophical Quarterly 33 (1996) 421-32.
"William Heytesbury on Knowledge: Epistemology Without Necessary and Sufficient Conditions," History of Philosophy Quarterly 12 (1995) 347-66.
Sometime around 1335 William Heytesbury proposed the following account of what he called knowledge in the ordinary sense: "to know is nothing other than unhesitatingly to apprehend the truth -- i.e., to believe unhesitatingly that it is so when it is so in reality." Despite the ease with which counterexamples to this proposal can be formulated, Heytesbury's proposal deserves our attention. Its apparent inadequacy stems from the mistaken presupposition that this must be a criterion of knowledge. Once we set aside that interpretive bias, we can see this proposal as an interesting attempt to characterize ordinary empirical knowledge as distinct from demonstrative scientia.
"Henry of Ghent and the Twilight of Divine Illumination," Review of Metaphysics 49 (1995) 49-75.
Henry of Ghent, in the opening questions of his Summa , makes the last sustained medieval attempt to save Augustine's theory of divine illumination. His efforts are particularly interesting, because he tries to make room for divine illumination while embracing much of Aristotle's theory of cognition, in particular agent intellect's role in abstraction. In order to incorporate divine illumination within a generally Aristotelian framework, Henry develops a distinctive and philosophically interesting argument: he argues that the human mind, on its own, is unable to grasp the real natures of things, even as they occur in the natural world.
"Justified Until Proven Guilty: William Alston's New Epistemology" in Philosophical Studies 72 (1993) 1-33.
In "Perceiving God" William Alston argues that we cannot show that our most basic beliefs are justified. Our only option, he says, is to suppose that they are justified and act accordingly. Here I argue that Alston is not entitled to this last, comforting, solution. If our epistemic situation is as Alston claims, then we have no reason, pragmatic or otherwise, to suppose that we ever have knowledge.
Review of Eleonore Stump, Aquinas, in Mind (forthcoming).
Review of John Inglis, On Aquinas , in Philosophical Books (forthcoming).
Review of Thomas Aquinas, On Evil (translations by R. Regan and J.A. & J.T. Oesterle) in Review of Metaphysics (forthcoming).
Review of Dennis Des Chene, Life’s Form: Late Aristotelian Conceptions of the Soul, in The Philosophical Review 111 (2002) 308-10.
Review of Anthony Kenny, Aquinas on Being , in Notre Dame Philosophical Reviews (2003).
“William Crathorn,” in J. Gracia and T. Noone (eds.) The Blackwell Companion to Medieval Philosophy (Oxford: Blackwell, 2003).
Review of Stephen J. Pope, The Ethics of Aquinas, in Notre Dame Philosophical Reviews (2003).
Review of Richard Cross, The Physics of Duns Scotus: The Scientific Context of a Theological Vision, in Speculum 77 (2002) 1268-70.
Review of Armand Maurer, The Philosophy of William of Ockham in the Light of Its Principles in Journal of the History of Philosophy 38 (2000) 590-91.
Review of John Finnis, Aquinas: Moral, Political, and Legal Theory in Faith and Philosophy 17 (2000) 407-13.
The Routledge Encyclopedia of Philosophy (1998). Articles on Peter Aureol, William Crathorn, Robert Holcot, and Peter John Olivi.
Review of Jerome Gellman, Experience of God and the Rationality of Theistic Belief in The Philosophical Review 107 (1998) 624-26.
Review of Thomas Nagel, Other Minds: Critical Essays 1969- 1994 in Review of Metaphysics 50 (1997) 166-68.
Review of Simon Kemp, Cognitive Psychology in the Middle Ages in Isis 88 (1997) 703-4.
Review of Roderick Chisholm, A Realistic Theory of Categories: An Essay on Ontology in Review of Metaphysics 666-67.
Review of John Wippel, Mediaeval Reactions to the Encounter Between Faith and Reason in The Review of Metaphysics 50 (1997) 179-80.
Review of Francisco Suarez, On Efficient Causality. Metaphysical Disputations 17, 18, and 19 (translated by Alfred Freddoso) in The Philosophical Review 105 (1996) 533-35.
Review of Robert Fogelin, Pyrrhonian Reflections on Knowledge and Justification in The Review of Metaphysics 49 (1996) 653-54.
Review of Stephen Everson, Language (Companions to Ancient Thought 3) in The Review of Metaphysics 49 (1996) 650- 51.
Review of Robert Audi, Action, Intention, and Reason in The Review of Metaphysics 49 (1995) 398-400.
Review of Anthony Kenny's Aquinas on Mind in The Philosophical Review 103 (1994) 745-48.
Review of Richard Dales's Medieval Discussions of the Eternity of the World in Speculum (July 1992) 654-656 (co-authored with Norman Kretzmann).
Of the many areas of philosophy to which late medieval thinkers made original and insightful contributions, none is more worthy of study than their work on human cognition and knowledge. Many of the issues that dominate philosophy of mind and epistemology today -- mental representation, materialism, direct versus representational realism, foundationalism, skepticism -- were hotly debated during the scholastic period. Indeed, in many cases the scholastics were the first in the Western philosophical tradition to give these problems sustained consideration.
The book begins with the theoretical foundations of scholastic accounts of cognition, and moves toward the underlying epistemological concerns that became increasingly prominent as the scholastic period developed. My point of departure is Thomas Aquinas (1225-1274), the first in the later medieval period to establish a coherent and comprehensive account of cognition and knowledge. I contrast Aquinas's work with its later medieval criticism and frequent rejection, focusing in particular on two figures: Peter John Olivi (1248-1298) and William Ockham (ca.1285-1347).
I have sought, by looking at Aquinas through the eyes of his near contemporaries, to reach a clearer understanding of Aquinas's own views. Just as importantly, I have tried to work out in detail some of the novel theories of mind and cognition offered by later scholastics. The heart of the book is my discussion of Olivi and Ockham. These two Franciscans, living a generation apart, offer similar challenges to Aquinas and traditional accounts of cognition. Both reject analyses of thought and perception that postulate inner representations mediating between our cognitive acts and the external objects of those acts. Their alternative proposals eliminate all such intermediaries in favor of direct realism.
Along the way toward working out the details of their accounts I take up many of the central problems (then and now) in the philosophy of mind and epistemology. Separate chapters are devoted to the medieval notion of intentionality, the roles of resemblance and causality in explaining mental representation, and the degree of passivity in perception. I go on to argue that, contrary to what is commonly supposed, Aquinas holds a theory of perception that involves intermediaries of a sort that most proponents of direct realism would reject. Hence the proposals of Olivi and Ockham constitute a genuine alternative to standard scholastic accounts.
The "Treatise on Human Nature" is the most philosophically rich section of the Summa theologiae; it contains Aquinas's definitive statements on the mind-body problem, action theory, sensation, and the workings of intellect. Although one of the most familiar parts of Aquinas's corpus, the Treatise is not well understood. I hope to foster modern appreciation for Aquinas by considering the text in careful philosophical detail. Rather than offer a running commentary, I focus on some of the most interesting portions of the Treatise, always considering them in the context of Aquinas's full corpus, with an eye to the best medieval and modern commentators and critics.
Perhaps the most far-reaching ideas in the Treatise come from Aquinas's attempt to explain human nature in terms of soul and body, without falling into either a dualism of mind versus matter, or a reductive materialism according to which matter, in the final analysis, is all there is. He avoids dualism by holding that soul and body are united by Aristotle's form-matter relationship in such a way as to produce a single, unified substance. He avoids reductive materialism by analyzing the entire physical world not in terms of various groupings of physical stuff, in assorted sizes and colors, but as diverse modes of what he calls actuality. Sometimes this actuality exists in a physical mode, sometimes not. It is distinctive of the human intellect that it is entirely nonphysical, even though it is a unified part of a physical human being. Viewed from Aquinas's perspective, there is nothing puzzling about such immateriality. Given that all we see are physical modes of actuality, we tend to assume that physical stuff is all there is. Our problem, Aquinas thinks, is that our imaginations won't go beyond that, and so we fail to see that our material world is just one way in which actuality is manifested.
Just as Aquinas insists on the unity of the soul-body composite, so he stresses that the workings of the soul are performed not by isolated faculties, but by complexly interrelated operations. Sensation, in human beings, takes much of its content from the intellect's conceptualization. Intellect, in turn, constantly relies on the senses so as to frame its thoughts in light of sensory images. The bases of human action are likewise cooperative. Freedom of choice stems from will and intellect making choices in tandem. "Weakness of will" aptly describes those cases where the will, due to temptation or habit, fails to take seriously the intellect's judgment about the proper course of action. Because Aquinas believes that human beings have an inherent sense of moral truth (synderesis), weakness of will lies at the heart of Aquinas's account of immoral action.