�ֲ���ý

overview

Robert Pasnau’s research extends all across the field of philosophy, but particularly concentrates on its history, especially from the later Middle Ages into the early modern era. He is the editor of the��Cambridge History of Medieval Philosophy��and the founding editor of��Oxford Studies in Medieval Philosophy. His most recent book, based on his Isaiah Berlin lectures at Oxford, is��After Certainty: A History of Our Epistemic Ideals and Illusions��(OUP 2017). He is a past-president of the American Philosophical Association, and a fellow of the Paris Institute for Advanced Studies.
��
For more information, see . For his medieval philosophy blog, .

selected publications

“Medieval Zeal and Modern Blame” (Presidential Address), Proceedings and Addresses of the American Philosophical Society 99 (2025) 59–78.

If the importance of an idea is measured by that idea’s influence, then the most important medieval contribution to the history of philosophy is the freewill problem. That problem, in its distinctive modern form, requires a particular conception of freedom and a particular conception of human nature, both revolving around a special power within us, the power of will. These ideas appeared in their present form only toward the end of the Middle Ages. In this talk I consider why this familiar approach to the will took hold in the Middle Ages. My conclusion is that it was needed to justify the zealous attitudes toward morality that dominated medieval Christian philosophy. Those attitudes, I argue, remain with us to this day.

“Who Killed the Causality of Things?” Nous 59 (2025) 771–95.

It’s a familiar claim in recent philosophy that causation is a relationship between events. But, famously, things didn’t used to be that way. Throughout antiquity, the Middle Ages and the early modern period, causation was understood as a relationship between substances and/or powers.�� When did this sort of “agent causation” die? And who killed it? The answer turns out to be surprising.

“Nominalism’s Modal Paradise Lost,” Oxford Studies in Medieval Philosophy 11 (2025) 181–209.

Nominalism in all of its manifestations, from Abelard to Quine, grows out of ontological scruples. For William Ockham and his followers in the fourteenth century, nominalism was centrally concerned with a more parsimonious treatment of the ten Aristotelian categories of being. But when it came to the alethic modalities of possibility and necessity, the nominalist program suddenly turns expansive, or so it has seemed to recent commentators, who have found in the nominalists a commitment to vast realms of merely possible beings,�� and even to a possible-worlds semantics for modality. Here I argue that, quite contrary to how the nominalists are generally read, they take particular care to avoid an ontological commitment to possibilia. Indeed, although their broader semantic views make it quite natural for them to analyze modal sentences in terms of possible worlds, they deliberately eschew this way of proceeding, even at the cost of foregoing the explanatory power that their semantic theories have in other domains.

"Where Socratic Akrasia Meets the Platonic Good," Journal of the History of Philosophy 59 (2021) 1-21.

The Protagoras's case against akrasia comes in two stages. First, at 352bc, we get an extremely quick argument grounded on knowledge as an epistemic ideal. This argument does not persuade the many, and so the dialogue turns, starting at 355a, to a technical and carefully developed argument aimed that proceeds on an entirely different basis. This argument has considerable force, but only once we make certain idealizing assumptions about an agent's ability to grasp the unitary, homogeneous nature of value. Reading the dialogue in this way offers the further tantalizing possibility of showing us precisely where Socrates's thought leaves off and Plato's begins: that the dialogue takes off from the famous and historical Socratic rejection of akrasia and then attempts to ground that dictum in a novel argument, one that displays Plato's characteristic interest in the distance between surface appearances and ultimate reality.

"Medieval Modal Spaces," Proceedings of the Aristotelian Society suppl. vol. 94 (2020) 225-54.

There is often said to be something peculiar about the history of modal theory up until the turn of the fourteenth century, when John Duns Scotus decisively reframed the issues. This impression of dramatic discontinuity is almost entirely a misimpression. Premodern philosophers prescind from the wide-open modal space of all possible worlds because they seek to adapt their modal discourse to the explanatory and linguistic demands of their context.

“Belief in a Fallen World,” Res Philosophica (Special Issue on the Philosophy of Religion) 95 (2018) 531-59.

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.

"," in J. Hause (ed.), Aquinas's Summa theologiae: A Critical Guide (Cambridge: Cambridge University Press, 2018) 10-28.

Suppose we ask of Aquinas's talk of form and matter, actuality and potentiality, substance and accident: how much of this is ontology, and how much is mere ideology? The correct answer is that very little of it is ontology. But that is not to say that the rest is mere ideology, because the ideology serves to map the basic modal structure of reality.

"," Analytic Philosophy 57 (2016) 253-84.

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.

"," in B. Loewer and J. Schaffer (eds.), A Companion to David Lewis (Oxford: Blackwell, 2015) 60-79.

Reading the history of philosophy from a Lewisian perspective.

"," Philosophical Studies 172 (2015) 2315-2339.

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.

"," Journal of the American Philosophical Association 1 (2015) 257-75.

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.

"," Journal of Philosophy 111 (2014) 608-30.

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.

"," Mind 122 (2014) 987-1021.

Epistemology today centrally concerns the conceptual analysis of knowledge. Historically, however, this is a concept that philosophers have seldom been interested in analyzing, 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.