The most powerful skeptical challenge to knowledge and justification is Pyrrhonian. It challenges nonskeptics to identify non-question begging warrant for their beliefs whereby they will not simply assume a point needing support in light of skeptical questions. The skeptical challenge is comprehensive, bearing on warranting conditions in general. Any answer given to such a comprehensive challenge apparently relies on a warranting condition being questioned. From this two questions emerge. First, is the skeptical challenge itself question begging in a way that undermines its epistemic significance? Second, is question begging necessarily an epistemic defect? This paper answers no to the first question, and identifies the problem facing skeptics who presuppose an affirmative answer to the second question. The problem stems from the availability of certain conceptions of epistemic rationality that do not prohibit question begging unqualifiedly.

This paper has three parts. First, a discussion of our use of intuitions as evidence (reasons) in logic, mathematics, philosophy (hereafter, “the a priori disciplines”). Second, an explanation of why intuitions are evidence. The explanation is provided by modal reliabilism—the doctrine that there is a certain kind of qualified modal tie between intuitions and the truth. Third, an explanation of why there should be such a tie between intuitions and the truth. This tie is a consequence of what, by definition, it is to possess the concepts involved in our intuitions. These three parts form the basis of a unified account of a priori evidence and, in turn, a priori knowledge.

In my book In Defense of Pure Reason, I offer an extended defense of the idea of a priori justification and, more specifically, of a rationalist conception of such justification: one according to which rational insight or intuition provides genuine justification for claims that need not be merely definitional or tautological in character. In the relatively brief space available to me on the present occasion, I want to present and defend, necessarily in rather broad strokes, four of the most central claims that are discussed at much greater length in that book. I will say the most about the first of these theses, somewhat less about the second and third, and only a very little about the fourth.

In this paper I argue that there are excellent reasons to embrace nonrelational (adverbial) analyses of sensations and intentional states. I shall further argue, however, that the epistemology of experience requires that we recognize at least one conscious state that is genuinely relational—awareness or acquaintance. It is through the relational state of being acquainted with non-relational mental states that one can end a regress of justification.

McDowell and Putnam are right to insist that objective knowledge is possible only because we are open to the world in perception, but neither of them offers an adequate account of the relationship between perception and perceptual judgments (which are at the core of our most fundamental knowledge of the world). This paper, intended as a contribution to the development of a sophisticated commonsense realism, proposes an account in terms of which perceptions acquire the status of perceptual judgments to the extent that they are imbedded in and engaged with the high-level patterns of consciousness and reasoning characteristic of judgments. This in turn explains how the contents of perceptual judgments which are to be understood as refinements of contents of the relevant perceptions apply to a world that is largely independent of the perceiver and knower.

A person’s authoritative self-knowledge about the contents of his or her own beliefs is thought to cause problems for content externalism, for it appears to yield arguments constituting a wholly non-empirical source of empirical knowledge: knowledge that certain particular objects or kinds exist in the environment. I set out this objection to externalism, and present a new reply. Possession of an externalist concept is an epistemological skill: it depends upon the subject’s possession of demonstratively-based knowledge about the object or kind to which it refers. Thus, a person’s knowledge that he or she has an externalist belief, since this depends upon actually having that belief, and therefore upon possessing the relevant externist concept, presupposes knowledge about the object/kind in question, which provides a direct and perfectly empirical source of knowledge that this object/kind exists. Hence, the putatively problematic arguments do not constitute a non-empirical source of such empirical knowledge.

We propose to extend a reliabilist perspective from epistemology to the very concept of rational justification. Rationality is defined as a cognitive virtue contextually relative to an information domain, to the mean performance of a cognitive community, and to normal conditions of information gathering. This proposal answers to the skeptical position derived from the evidence of the cognitive fallacies and, on the other hand, is consistent with the ecological approach to the cognitive biases. Rationality is conceived naturalistically as a control system of the flow of information: reliabilism is the approach that qualifies this system as virtuous. There can be specific-domain devices selected by evolution, although the constraints of the very flow of information can be also represented, even with imperfect means of formalization, and then rationality becomes reflective. Reliable rationality is postulated in conclusion as a more philosophically abstract concept than maximal, minimal or bounded rationality.

In recent years empiricism has come under attack. Some argue that the view is incoherent and conclude, on that basis, that some knowledge is a priori. Whatever the merits of such arguments against empiricism, they cannot be parlayed into an argument in support of the a priori unless the latter is not open to those arguments. My primary contention is that the a priori is open to the arguments offered against empiricism. Hence, they do not advance the case for the a priori. I go on to offer an alternative strategy. The leading idea is that, instead of arguing against empiricism, rationalists should marshal empirical support for their position.

It has been suggested, recently and not so recently, by a number of analytic epistemologists that reliabilist and externalist accounts of justification and knowledge are inadequate responses to the goals of traditional epistemology and other goals of inquiry. But philosophers of science decry reliabilism and externalism because they are connected to traditional, analytic epistemology, an outmoded and utopian form of inquiry. Clearly, both groups of critics cannot be right. I think both groups are guilty of conceptual confusions that, once clarified, should allow the naturalization project to stand forth in a rather attractive light.

Sensory qualities are objective properties; indeed, on the evidence, they are physical properties. However, what makes a physical property the sensory quality it is is its relationship to sensory experiences of perceivers. For instance, the redness of a surface is a physical property of the surface; what makes that physical property surface red is the fact that it disposes surfaces to look red to appropriate visual perceivers in appropriate viewing circumstances. What it is like for something to look red—that is, the actual phenomenal character of visual experiences as of something red—is also a physical property; on the evidence, it is a physical property of the brain.

Resistance to contextualism comes in the form of many very different types of objections. My topic here is a certain group or family of related objections to contextualism that I call “Now you know it, now you don’t” objections. I responded to some such objections in my “Contextualism and Knowledge Attributions” a few years back. In what follows here, I will expand on that earlier response in various ways, and, in doing so, I will discuss some aspects of David Lewis’s recent paper, “Elusive Knowledge.”

Epistemology needs a social branch to complement its traditional, ‘individualist’ branch. Like its individualist sister, social epistemology would be an evaluative enterprise. It would assess (actual and possible) social practices in terms of their propensities to promote or inhibit knowledge, where knowledge is understood in the sense of true belief. Social epistemology should examine the practices of many types of players, as well as technological and institutional structures: speakers, hearers, gate-keepers of communication (e.g., editors, publishers, referees), communication technologies and their applications, and legal and economic arrangements that influence the epistemic quality of public speech. A mixture of analytical tools should be employed to assess practices in terms of their likely knowledge outcomes, tools that include Bayesian probability theory, economic theory, and empirical inquiry.

For the classical Greek philosophers, the cultivation of human rationality is a central ingredient of education andedification. But notions of reason and rationality have received various interpretations. A plurality of interpretations directs our attention to the general philosophical queries, What is rationality? and Why should we be rational? In this paper, I consider only briefly the first question by distinguishing three aspects of rationality in Section 2. Then I shall use, in Section 3, these three notions to give nine reformulations of the puzzling question ‘Is it rational to be rational?’. My main task is concerned with the analysis of the relevant questions, not in their answers. I hope this approach helps us to understand in a clearer way the nature and importance of human rationality.

With few exceptions, philosophers typically have contended that knowledge worthy of the name is beyond time and place. This venerable idea was turned on its head in the emergence of a rival view of knowledge as historical in the wake of the French Revolution. A claim that knowledge is not ahistorical but historical resolves some of these difficulties while creating others. This paper will briefly consider several of these difficulties, including how to argue for this position, the differences between contextualism, or a view of knowledge as cultural, and historicism, as well as issues concerning relativism and cognitive objectivity. It will argue that after the decline of foundationalism, a conception of knowledge as historical is our most promising approach.

The various forms of human knowledge can be regarded as an integral, historically developing system. Universal cultural categories are a system-building factor. They form the core of the cultural and historical code by which a type of society is reproduced. The differences in the meaning of universals in traditional and technogenic cultures determine the difference in the organization of knowledge forms. The modern system of knowledge is developing under two general conditions: the search for a new worldview, as well as the intensification of cross-cultural dialogue. The transition to the technological mastery of complex, historically evolving systems forms new images of nature from the scientific perspective, as well as new strategies of activity. These new images of nature accord not only with the values of the European culture, but correlate with the worldviews of different Eastern cultures which had previously been rejected as unscientific.

I review a familiar skeptical argument from Hume, and conclude that it requires us to accept that there is no necessary relation between beliefs about the world and their evidential grounds; that is, there is no logical or quasi-logical relation between empirical beliefs and their grounds, such that their grounds entail them, or even make them probable. I then argue that generic reliabilism can accommodate this fact about evidential grounds in a non-skeptical way. According to reliabilism, the grounds for our beliefs constitute good evidence so long as they are contingently reliable. Next I argue that agent reliabilism successfully addresses two related problems for other versions of reliabilism: the fact that beliefs can be reliably formed by accident, and the need for subjective justification. Finally, I explain why agent reliabilism is properly conceived as a version of virtue epistemology.

Appeal to the idea of an epistemic virtue promises insight into our practices of epistemic evaluation through employing a distinctive view of the ways in which we formulate and respond to reasons. Traits of ‘epistemic character’ guide our reasoning and reflection, and can be responsible for various forms of irrationality. One component of such a view is that emotions, sentiments and other affective states are far more central to questions of epistemic rationality than is commonly supposed. This paper explains why this is so, and then illustrates the value of this way of looking at the matter by considering two particular examples: the role of states of doubt in regulating our deliberations and inquiries; and the character of our response to some distinctive kinds of irrationality. This will involve a brief discussion of some forms of epistemic akrasia.

I argue that, according to Descartes, even mathematics is not immune from doubt and absolutely reliable, and hence fails to grant the ultimate justification of science. Descartes offers two arguments and a corollary to support this view. They are sufficient to show that the mathematical atheist cannot justifiably claim to have absolutely certain knowledge even of simple mathematical truths. Philosophical reflection itself turns out to be the only alternative means to provide knowledge with a stable foundation.