Michael WiIliams maintains that skepticism about the extemal worId is vitiated by a commitment to foundationalism and epistemological realism. (The latter is, approximately, the view that there is such a thing as knowledge of the extemal world in general, which the skeptic can take as a target). I argue that skepticism is not encumbered in the ways Williams supposes. What matters, first of all, is that we can’t perceive the difference between being in an ordinary environment and being in the (...) sort of situation the skeptic describes (e.g. having one’s brain manipulated by deceitful experimenters). This point can be upheld without embracing any substantial foundationalist tenet, such as the existence of basic beliefs, the availabiIity of something “given,” or the epistemic priority of experience. As to “epistemological realism,” I find that Williams has offered no principled way to distinguish between ordinary chaIIenges to knowledge and skeptical challenges which, supposedly, have no cIaim on our concem. (shrink)

Introduction As the title indicates, the chief focus of this book is epistemic justification. But just what is epistemic justification and what is its place ...

A comprehensive defence of the rationalist view that insight independent of experience is a genuine basis for knowledge.

Nozick analyzes fundamental issues, such as the identity of the self, knowledge and skepticism, free will, the foundations of ethics, and the meaning of life.

In the mid-eighteenth century David Hume argued that successful prediction tells us nothing about the truth of the predicting theory. But physical theory routinely predicts the values of observable magnitudes within very small ranges of error. The chance of this sort of predictive success without a true theory suggests that Hume's argument is flawed. However, Colin Howson argues that there is no flaw and examines the implications of this disturbing conclusion; he also offers a solution to one of the central (...) problems of Western philosophy, the problem of induction. (shrink)

In Unnatural Doubts, Michael Williams constructs a masterly polemic against the very idea of epistemology, as traditionally conceived.

Consider the skeptic about the external world. Let’s straightaway concede to such a skeptic that perception gives us no conclusive or certain knowledge about our surroundings. Our perceptual justification for beliefs about our surroundings is always defeasible—there are always possible improvements in our epistemic state which would no longer support those beliefs. Let’s also concede to the skeptic that it’s metaphysically possible for us to have all the experiences we’re now having while all those experiences are false. Some philosophers dispute (...) this, but I do not. The skeptic I want to consider goes beyond these familiar points to the much more radical conclusion that our perceptual experiences can’t give us any knowledge or even justification for believing that our surroundings are one way rather than another. (shrink)

The sceptic about the external world presents us with a paradox: an apparently acceptable argument for an apparently unacceptable conclusion—that we do not know anything about the external world. Some paradoxes, for instance the liar and the sorites, are very hard. The defense of a purported solution to either of these two inevitably deploys the latest in high-tech philosophical weaponry. On the other hand, some paradoxes are not at all hard, and may be resolved without much fuss. They do not (...) contain profound lessons about the human condition. Where should we place the sceptical paradoxes? (shrink)

David Lewis (1941-2001) was Class of 1943 University Professor of Philosophy at Princeton University. His contributions spanned philosophical logic, philosophy of language, philosophy of mind, philosophy of science, metaphysics, and epistemology. In On the Plurality of Worlds, he defended his challenging metaphysical position, "modal realism." He was also the author of the books Convention, Counterfactuals, Parts of Classes, and several volumes of collected papers.

Is Bayesian decision theory a panacea for many of the problems in epistemology and the philosophy of science, or is it philosophical snake-oil? For years a debate had been waged amongst specialists regarding the import and legitimacy of this body of theory. Mark Kaplan had written the first accessible and non-technical book to address this controversy. Introducing a new variant on Bayesian decision theory the author offers a compelling case that, while no panacea, decision theory does in fact have the (...) most profound consequences for the way in which philosophers think about inquiry, criticism and rational belief. The new variant on Bayesian theory is presented in such a way that a non-specialist will be able to understand it. The book also offers new solutions to some classic paradoxes. It focuses on the intuitive motivations of the Bayesian approach to epistemology and addresses the philosophical worries to which it has given rise. (shrink)

The argument is not, however, problem-free. First: while the meaning of s might not guarantee a verifying state of affairs, mightn’t the fact of one’s believing that s is true guarantee a verifying state of affairs? And mightn’t this fact be exploited to secure knowledge of truths that are deeply contingent? Second: the argument seems to rely on the principle that if I can conceive that not P is actually the case, then I do not know that P. But it (...) is generally agreed that a knowledge-conferring warrant for some P need not offer a watertight guarantee of P and thus need not render it inconceivable that the actual world falsifies P. Why then require such a guarantee when it comes to priori warrant? The first objection is that a guarantee of truth need not come from semantics. The second is that no such guarantee is required for a priori knowledge. I shall be exploring both of these ideas in what follows. (shrink)

The dominant response to this problem of the criterion focuses on the alleged requirement that we need to know a belief source is reliable in order for us to acquire knowledge by that source. Let us call this requirement, “The KR principle”.

Much has been written about epistemological skepticism in the last ten or so years, but there remain some unanswered questions concerning the structure of what has become the canonical Cartesian skeptical argument. In this paper, I would like to take a closer look at this structure in order to determine just which epistemic principles are required by the argument.

This book is concerned with the alleged capacity of the human mind to arrive at beliefs and knowledge about the world on the basis of pure reason without any dependence on sensory experience. Most recent philosophers reject the view and argue that all substantive knowledge must be sensory in origin. Laurence BonJour provocatively reopens the debate by presenting the most comprehensive exposition and defence of the rationalist view that a priori insight is a genuine basis for knowledge. This important book (...) will be at the centre of debate about the theory of knowledge for many years to come. (shrink)

... and Normative Epistemology The Distinction Between Metaepistemology and Normative Epistemology Although this terminology is relatively new, ...

In an important study, Lawrence Sklar has defended a doctrine of methodological conservatism (very roughly, the principle that a proposition derives some sort of epistemic warrant from being believed). I argue that Sklar's careful formulation of methodological conservatism remains too strong, and that a yet weaker version of the doctrine cannot be successfully defended. I also criticize Sklar's argument that the rejection of methodological conservatism would result in total skepticism. Finally, I turn to a closely related issue, and try to (...) show why different people with the same evidence should be justified in believing the same things. (shrink)

Inspired by the work of Wilfrid Sellars, Michael Williams launches an all-out attack on what he calls "phenomenalism," the idea that our knowledge of the world rests on a perceptual or experiential foundation.

This paper compares two kinds of epistemic principles---an underdetermination principle and a deductive closure principle. It argues that each principle provides the basis for an independently motivated skeptical argument. It examines the logical relations between the premises of the two kinds of skeptical argument and concludes that the deductive closure argument cannot be refuted without refuting the underdetermination argument. The underdetermination argument, however, can be refuted without refuting the deductive closure argument. In this respect, the deductive closure argument is the (...) stronger of the two. (shrink)

Inspired by the work of Wilfrid Sellars, Michael Williams launches an all-out attack on what he calls "phenomenalism," the idea that our knowledge of the world rests on a perceptual or experiential foundation. The point of this wider-than-normal usage of the term "phenomenalism," according to which even some forms of direct realism deserve to be called phenomenalistic, is to call attention to important continuities of thought between theories often thought to be competitors. Williams's target is not phenomenalism in its classical (...) sense-datum and reductionist form but empiricism generally. Williams examines and rejects the idea that, unless our beliefs are answerable to a "given" element in experience, objective knowledge will be impossible. Groundless Belief was first published in 1977. This second edition contains a new afterword in which Williams places his arguments in the context of some current discussions of coherentism versus the Myth of the Given and explains their relation to subsequent developments in his own epistemological views. (shrink)

The problem of induction and the problem of Cartesian/brain-in-the-vat skepticism have much in common. Both are instances of a general problem of defeasible justification . I use the term "defeasible justification" to refer to a relation between a piece of evidence.