Infinitism is an ancient view in epistemology about the structure of knowledge and epistemic justification, according to which there are no foundational reasons for belief. The view has never been popular, and is often associated with skepticism, but after languishing for centuries it has recently begun a resurgence. Ad Infinitum presents new work on the topic by leading epistemologists. They shed new light on infinitism's distinctive strengths and weaknesses, and address questions, new and old, about its account of justification, reasoning, epistemic responsibility, disagreement, and trust, among other important issues. The volume clarifies the relationship between infinitism and other epistemological views, such as skepticism, coherentism, foundationalism and contextualism, and it offers novel perspectives on the metaphysics, epistemology, and ethics of regresses and reasons.

The Gettier Problem has shaped most of the fundamental debates in epistemology for more than fifty years. Before Edmund Gettier published his famous 1963 paper, it was generally presumed that knowledge was equivalent to true belief supported by adequate evidence. Gettier presented a powerful challenge to that presumption. This led to the development and refinement of many prominent epistemological theories, for example, defeasibility theories, causal theories, conclusive-reasons theories, tracking theories, epistemic virtue theories, and knowledge-first theories. The debate about the appropriate use of intuition to provide evidence in all areas of philosophy began as a debate about the epistemic status of the 'Gettier intuition'. The differing accounts of epistemic luck are all rooted in responses to the Gettier Problem. The discussions about the role of false beliefs in the production of knowledge are directly traceable to Gettier's paper, as are the debates between fallibilists and infallibilists. Indeed, it is fair to say that providing a satisfactory response to the Gettier Problem has become a litmus test of any adequate account of knowledge even those accounts that hold that the Gettier Problem rests on mistakes of various sorts. This volume presents a collection of essays by twenty-six experts, including some of the most influential philosophers of our time, on the various issues that arise from Gettier's challenge to the analysis of knowledge. Explaining Knowledge sets the agenda for future work on the central problem of epistemology.

The Gettier Problem has shaped most of the fundamental debates in epistemology for more than fifty years. Before Edmund Gettier published his famous 1963 paper, it was generally presumed that knowledge was equivalent to true belief supported by adequate evidence. Gettier presented a powerful challenge to that presumption. This led to the development and refinement of many prominent epistemological theories, for example, defeasibility theories, causal theories, conclusive-reasons theories, tracking theories, epistemic virtue theories, and knowledge-first theories. The debate about the appropriate use of intuition to provide evidence in all areas of philosophy began as a debate about the epistemic status of the 'Gettier intuition'. The differing accounts of epistemic luck are all rooted in responses to the Gettier Problem. The discussions about the role of false beliefs in the production of knowledge are directly traceable to Gettier's paper, as are the debates between fallibilists and infallibilists. Indeed, it is fair to say that providing a satisfactory response to the Gettier Problem has become a litmus test of any adequate account of knowledge even those accounts that hold that the Gettier Problem rests on mistakes of various sorts. This volume presents a collection of essays by twenty-six experts, including some of the most influential philosophers of our time, on the various issues that arise from Gettier's challenge to the analysis of knowledge. Explaining Knowledge sets the agenda for future work on the central problem of epistemology.