The thirty chapters work through various fundamental metaphysical issues, sometimes focusing more on scholastic thought, sometimes on the seventeenth century.

After Certainty offers a reconstruction of the history of epistemology, understood as a series of changing expectations about the cognitive ideal that we might hope to achieve in this world. Pasnau ranges widely over philosophy from Aristotle to the 17th century, and examines in some detail the rise of science as an autonomous discipline.

This book is a major contribution to the history of philosophy in the later medieval period (1250-1350). It focuses on cognitive theory, a subject of intense investigation during these years. In fact many of the issues that dominate philosophy of mind and epistemology today - intentionality, mental representation, scepticism, realism - were hotly debated in the later medieval period. The book offers a careful analysis of these debates, primarily through the work of Thomas Aquinas, John Olivi, and William Ockham. Each (...) of these figures attempts to reconceptualise cognition along direct realist lines, criticising in the process the standard Aristotelian account. Though of primary interest to medieval philosophers, the book presupposes no background knowledge of the medieval period, and will therefore interest a broader community of philosophers concerned with the origins of contemporary cognitive theory. (shrink)

This is a major new study of Thomas Aquinas, the most influential philosopher of the Middle Ages. The book offers a clear and accessible guide to the central project of Aquinas' philosophy: the understanding of human nature. Robert Pasnau sets the philosophy in the context of ancient and modern thought, and argues for some groundbreaking proposals for understanding some of the most difficult areas of Aquinas' thought: the relationship of soul to body, the workings of sense and intellect, the will (...) and the passions, and personal identity. Structured around a close reading of the treatise on human nature from the Summa theologiae and deeply informed by a wide knowledge of the history of philosophy and contemporary philosophy, this study will offer specialists a series of novel and provocative interpretations, while providing students with a reference commentary on one of Aquinas' core texts. (shrink)

Epistemology today centrally concerns the conceptual analysis of knowledge. Historically, however, this is a concept that philosophers have seldom been interested in analysing, particularly when it is construed as broadly as the English language would have it. Instead, the overriding focus of epistemologists over the centuries has been, first, to describe the epistemic ideal that human beings might hope to achieve, and then go on to chart the various ways in which we ordinarily fall off from that ideal. I discuss (...) in detail two historical manifestations of idealized epistemology — Aristotle and Descartes — and then consider how this perspective might make a difference to the discipline today. In the end, an idealized epistemology points toward a normative, prescriptive rather than descriptive enterprise. (shrink)

Controversy over the epistemology of disagreement endures because there is an unnoticed factor at work: the intrinsic value we give to self-trust. Even if there are many instances of disagreement where, from a strictly epistemic or rational point of view, we ought to suspend belief, there are other values at work that influence our all-things considered judgments about what we ought to believe. Hence those who would give equal-weight to both sides in many cases of disagreement may be right, from (...) the perspective of pure rationality. But their critics are right too, in seeing something undesirable in the consequences of giving equal weight. Among epistemologists, there is a tendency to set aside trust and other such non-epistemic factors, on the grounds that these are not germane to their topic. But ultimately, the value of self-trust shows signs of encroaching on the strictly epistemic question of when our beliefs may be said to be justified. Hence again, even if the equal-weighters are right about what is rational, they may be wrong about what knowledge requires. (shrink)

Philosophers today have largely given up on the project of categorizing being. Aristotle’s ten categories now strike us as quaint, and no attempt to improve on that effort meets with much interest. Still, no one supposes that reality is smoothly distributed over space. The world at large comes in chunks, and there remains a widespread intuition, even among philosophers, that some of these chunks have a special sort of unity and persistence. These, we tend to suppose, are most truly agents (...) and subjects, and are what exist in the most proper sense of the term. We believe, in other words, in substances. (shrink)

In an ideal epistemic world, our beliefs would correspond to our evidence, and our evidence would be bountiful. In the world we live in, however, if we wish to live meaningful lives, other epistemic strategies are necessary. Here I attempt to work out, systematically, the ways in which evidentialism fails us as a guide to belief. This is so preeminently for lives of a religious character, but the point applies more broadly.

It is important to distinguish between two ways in which God might be timelessly eternal: eternality as being wholly outside of time, versus the sort of timelessness that consists in lacking temporal parts, and so existing “all at once.” A prominent but neglected historical tradition, most clearly evident in Anselm, advocates putting God in time, but in an all-at-once sort of way that makes God immune to temporal change. This is an intrinsically plausible conception of divine eternality, which also sheds (...) light on the modern dispute over the endurance or perdurance of material objects. (shrink)

When objects are illuminated, the light they reflect does not simply bounce off their surface. Rather, that light is entirely reabsorbed and then reemitted, as the result of a complex microphysical event near the surface of the object. If we are to be physicalists regarding color, then we should analyze colors in terms of that event, just as we analyze heat in terms of molecular motion, and sound in terms of vibrations. On this account, colors are not standing properties of (...) objects, but events, or (more cautiously) properties associated with events. Accordingly, objects in the dark are no more colored than a turned-off stove is hot. Such an account requires rejecting some of what folk ordinarily say about color, but this is the most coherent version of color physicalism. (shrink)

Reflection on the history of skepticism shows that philosophers have often conjoined as a single doctrine various theses that are best kept apart. Some of these theses are incredible – literally almost impossible to accept – whereas others seem quite plausible, and even verging on the platitudinous. Mixing them together, one arrives at a view – skepticism – that is as a whole indefensible. My aim is to pull these different elements apart, and to focus on one particular strand of (...) skepticism that deserves sustained and respectful attention. The strand I have in mind I will refer to as epistemic defeatism. Roughly, in its most global form, it is the view that, in the final analysis, we have no good evidence for the truth of any proposition. Working through various historical texts, I attempt to untangle epistemic defeatism from neighboring views, and in particular to establish its independence from questions about knowledge. Having thus established the view's autonomy, I turn to the options for self-consciously accepting defeat. One may despair or one may have faith. But I will ultimately propose that the most attractive option – the option that preserves the most of our epistemic integrity – is to have hope. (shrink)

The first unquestionably big idea in the history of philosophy was the idea of form. The idea of course belonged to Plato, and was then domesticated at the hands of Aristotle, who paired form with matter as the two chief principles of his metaphysics and natural philosophy. In the medieval period, it was Aristotle’s conception of form and matter that generally dominated. This was true for both the Islamic and the Christian tradition, once the entire Aristotelian corpus became available. For (...) this reason, although there is much to say about the fate of Platonic Forms in medieval thought, the present chapter will focus on the Aristotelian tradition.1 Aristotelian commentators have been puzzled by form and matter for as long as there have been Aristotelian commentators. Indeed, it would not be too much to say that these are topics about which Aristotelians have never formed a very clear conception, and that their failure to do so was the principal reason why Aristotelianism ceased to be a flourishing research program from the seventeenth century onward. For those who aspire to a modern revival of Aristotelianism, the concepts of form and matter can easily take on the aspect of a kind of Holy Grail, such that if only we could get these ideas clearly in focus, we could see our way forward on any number of philosophical fronts, such as the union of mind and body, the coherence and endurance of substances, the nature of causality, and so on. The historical record, however, suggests that this hope is a snare and delusion, insofar as there has never been any such thing as the theory of form and matter. Although medieval philosophers of all kinds used this terminology incessantly, it had no more of a fixed meaning than does the ubiquitous contemporary philosophical talk of “properties.” Hence, the most a general survey of the topic can do is consider some of the more important areas of agreement and disagreement. (shrink)

The Cambridge History of Medieval Philosophy comprises over fifty specially commissioned essays by experts on the philosophy of this period. Starting in the late eighth century, with the renewal of learning some centuries after the fall of the Roman Empire, a sequence of chapters takes the reader through developments in many and varied fields, including logic and language, natural philosophy, ethics, metaphysics, and theology. Close attention is paid to the context of medieval philosophy, with discussions of the rise of the (...) universities and developments in the cultural and linguistic spheres. A striking feature is the continuous coverage of Islamic, Jewish, and Christian material. There are useful biographies of the philosophers, and a comprehensive bibliography. The volumes illuminate a rich and remarkable period in the history of philosophy and will be the authoritative source on medieval philosophy for the next generation of scholars and students alike. (shrink)

Medieval epistemology begins as ideal theory: when is one ideally situated with regard to one's grasp of the way things are? Taking as their starting point Aristotle's Posterior Analytics, scholastic authors conceive of the goal of cognitive inquiry as the achievement of scientia, a systematic body of beliefs, grasped as certain, and grounded in demonstrative reasons that show the reason why things are so. Obviously, however, there is not much we know in this way. The very strictness of this ideal (...) in fact gives rise to a body of literature on how Aristotle's framework might be relaxed in various ways, for certain specific purposes. In asking such questions, scholastic authors are in effect pursuing the project of social epistemology, by trying to adapt their ideal theory to the circumstances of everyday life. (shrink)

This volume, including sixteen contributions, analyses ancient and medieval theories of intentionality in various contexts: perception, imagination, and intellectual thinking. It sheds new light on classical theories and examines neglected sources, both Greek and Latin.

A theory of human nature must consider from the start whether it sees human beings in fundamentally biological terms, as animals like other animals, or else in fundamentally supernatural terms, as creatures of God who are like God in some special way, and so importantly unlike other animals. Many of the perennial philosophical disputes have proved so intractable in part because their adherents divide along these lines. The friends of materialism, seeing human beings as just a particularly complex example of (...) the sort of complex organic structure found everywhere on Earth, suppose that we are ultimately constituted out of just the same material from which squirrels and rabbits are made. The friends of dualism, instead, think that such a story can hardly do justice to what is special about human nature. Likewise, the friends of a libertarian, robustly non-deterministic conception of free will see something special in human spontaneity and moral responsibility. To their opponents, human beings operate on the same principles, albeit more complex, as do squid and plankton. These and other such disputes need not divide along religious lines. One may oppose naturalism without embracing a supernatural theistic perspective; one might, for instance, think it simply a matter of fact that human beings are fundamentally unlike other biological organisms, but yet not suppose we are made that way by any higher power. Conversely, the theist may think it part of the divine plan to have made human beings as nothing more than the most complex of biological organisms, constituted out of the same stuff and constrained by the same laws. So although the choice I have described between two perspectives –. (shrink)

A theory of how rationally to respond to disagreement requires a clear account of how to measure comparative reliability. Such an account faces a Generality Problem analogous to the well-known problem that besets reliabilist theories of knowledge. But whereas the problem for reliabilism has proved recalcitrant, I show that a solution in the case of disagreement is available. That solution is to measure reliability in the most fine-grained way possible, in light of all the circumstances of the present disagreement, but (...) behind a veil that precludes taking into account which views are one's own. This resolves two of the leading obstacles to understanding what disagreement rationally requires: the objection from neglecting the evidence, and the objection from absurd disagreements. Appealing to the contractualist's veil of ignorance also sheds an interesting light on the very different ways in which disagreement gets resolved in epistemology versus political theory. The comparison raises troubling questions on both sides, because it seems doubtful that the political theorist's usual strategies are epistemically rational, and it seems doubtful that the epistemologist's usual strategies are sufficiently attuned to what we care about. (shrink)

Beginning with a brief overview of Aquinas’ life and philosophical career, the authors introduce his overarching explanatory framework in order to provide the necessary background to his substantive theorizing in a wide range of areas: rational theology, metaphysics, philosophy of human nature, philosophy of mind, and ethical and political theory. Although not intended to provide a comprehensive evaluation of all aspects of Aquinas’ far-reaching writings, the volume does present a systematic introduction to the principal areas of his philosophy, attending no (...) less to his methods and argumentative strategies than to his ultimate conclusions. (shrink)

In a recent book, I attempt to use the metaphysics of Thomas Aquinas to defend a moderate view regarding 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. In this paper, I make a brief reply. (shrink)

A quick scan of the leading figures in western philosophy reveals that relatively few have made a name for themselves by defending intuitive, natural, and sensible positions. Aristotle is one, and perhaps Aquinas is another. Francisco Suarez, the sixteenth-century Spanish scholastic, would be a third. His invariable working procedure is to give copious consideration to the various ancient and medieval views, and then to find some sensible compromise position. But today Suarez can hardly claim to have a broad readership. Of (...) his fifty-four Metaphysical Disputations, only nine have now been published in English, while his other works remain almost entirely untranslated. This clear and accurate new translation aims to show readers what they have been missing. (shrink)

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. (shrink)

The first doctrine Peckham mentions as being under attack is of undoubtedly the TDI, according to which human beings are illuminated by "the unchangeable light" so as to attain the "eternal rules." This language of light and illumination is of course most closely associated with Augustine, but it permeates the entire Christian medieval tradition. Until Aquinas's time the TDI had played a prominent role in all the most influential medieval theories of knowledge, including those of Anselm, Albert the Great, Roger (...) Bacon, and, especially, Bonaventure. However, by the beginning of the fourteenth century the theory had fallen out of fashion. Indeed, the three best philosophers of the scholastic period--Aquinas, John Duns Scotus, and William Ockham--would all reject the theory in its standard form. Even by 1285 supporters of the TDI such as Peckham were evidently feeling rather defensive. It seems entirely plausible to attribute this attitude, in large part, to the influence of Aquinas's views on human knowledge. (shrink)

Democritus is generally understood to have anticipated the seventeenthcentury distinction between primary and secondary qualities. I argue that this is not the case, and that instead for Democritus all sensible qualities are conventional.

The Cambridge History of Medieval Philosophy comprises over fifty specially commissioned essays by experts on the philosophy of this period. Starting in the late eighth century, with the renewal of learning some centuries after the fall of the Roman Empire, a sequence of chapters take the reader through developments in many and varied fields, including logic and language, natural philosophy, ethics, metaphysics, and theology. Close attention is paid to the context of medieval philosophy, with discussions of the rise of the (...) universities and developments in the cultural and linguistic spheres. A striking feature is the continuous coverage of Islamic, Jewish, and Christian material. There are useful biographies of the philosophers, and a comprehensive bibliography. The volume illuminates a rich and remarkable period in the history of philosophy and will be the authoritative source on medieval philosophy for the next generation of scholars and students alike. (shrink)

The long history of theorizing about perception divides into two quite distinct and irreconcilable camps, one that takes sensory experience to show us external reality just as it is, and one that takes such experience to reveal our own mind. I argue that we should reject both sides of this debate, and admit that the phenomenal character of experience, as such, reveals little about the nature of the external world and even less about the mind.

For later medieval philosophers, writing under the influence of Aristotle’s natural philosophy and metaphysics, the human soul plays two quite different roles, serving as both a substantial form and a mind. To ask the natural question of why we need a soul at all – why we might not instead simply be a body, a material thing – therefore requires considering two very different sets of issues. The first set of issues is metaphysical, and revolves around the central question of (...) why a human being needs a substantial form. The second set of issues is psychological, and turns on the question of why we should suppose that our mind is aptly characterized as a soul. This chapter takes up these two questions in turn, and then turns to whether we should suppose that one and the same thing – a soul – is both substantial form and mind. This dual-function thesis is the most distinctive feature of later medieval psychology, and is one reason that work from this era remains well-worth reading today. Whereas modern thought furnishes many sophisticated discussions of the immateriality of mind, and the metaphysics of body, philosophers since Descartes have rarely considered that it might be one thing, the soul, that accounts for both thought and substantial unity. (shrink)

The third volume of The Cambridge Translations of Medieval Philosophical Texts will allow scholars and students access, for the first time in English, to major texts that form the debate over mind and knowledge at the center of medieval philosophy. Beginning with thirteenth-century attempts to classify the soul's powers and to explain the mind's place within the soul, the volume proceeds systematically to consider the scope of human knowledge and the role of divine illumination, intentionality and mental representation, and attempts (...) to identify the object of human knowledge in terms of concepts and propositions. The authors included are Henry of Ghent, Peter John Olivi, William Alnwick, Peter Aureol, William Ockham, William Crathorn, Robert Holcot, Adam Wodeham as well as two anonymous Parisian masters of arts. This volume will be an important resource for scholars and students of medieval philosophy, history, theology and literature. (shrink)

In an earlier work, 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.

Thomas Aquinas gives us many reasons to think that conceptual thought is linguistic in nature. Most notably, he refers to a mental concept as a verbum or word. He further says that such concepts may be either simple or complex, and that complex concepts are formed out of simple ones, through composition or division. These complex concepts may either affirm or deny a predicate of a subject. All of these claims suggest that conceptual thought is somehow language-like. Moreover, Aquinas would (...) have been led in this direction by several venerable traditions. Augustine, for instance, speaks of “the word that we speak in our heart, a word which is not Greek nor Latin nor part of any other language.” And Aristotle, at the beginning of his De interpretatione, says that spoken words are symbols or signs of mental concepts; later generations would take this claim to warrant a treatment of mental concepts as themselves a kind of language. But how exactly should we understand this apparent connection in Aquinas between thought and language? (shrink)

In August of 1989, as an eighteen-year-old atheist spending his last night at home before setting off cross-country for college, I had the one and only mystical experience of my life to date. Rather than grapple with expressing the content of that experience, let me quote from part of the record Blaise Pascal made of his own mystical experience, one that seems to have been similar in many respects to my own.

It is seven hundred years since Peter of John Olivi's death, and all of modernity has forgotten his legacy. All? Well, not entirely. One small village of indomitable Gauls still holds out against the forces of oblivion. While the empire of English-language scholarship has largely let Olivi's creative and influential work go unedited, untranslated, and unstudied, this hearty band of French scholars has persisted in exploring the fundamentals of his thought.This latest contribution focuses on some of the most innovative and (...) foundational features of Olivi's natural philosophy, revolving around the causal relationships that substances hold to one another. This is not, however, exactly a book on Olivi's theory of... (shrink)

The Cambridge History of Medieval Philosophy comprises over fifty specially commissioned essays by experts on the philosophy of this period. Starting in the late eighth century, with the renewal of learning some centuries after the fall of the Roman Empire, a sequence of chapters take the reader through developments in many and varied fields, including logic and language, natural philosophy, ethics, metaphysics, and theology. Close attention is paid to the context of medieval philosophy, with discussions of the rise of the (...) universities and developments in the cultural and linguistic spheres. A striking feature is the continuous coverage of Islamic, Jewish, and Christian material. There are useful biographies of the philosophers, and a comprehensive bibliography. The volume illuminates a rich and remarkable period in the history of philosophy and will be the authoritative source on medieval philosophy for the next generation of scholars and students alike. (shrink)