Marcus Willaschek

This paper develops a non-relativist version of contextualism about knowledge. It is argued that a plausible contextualism must take into account three features of our practice of attributing knowledge: (1) knowledge-attributions follow a default-and-challenge pattern; (2) there are preconditions for a belief's enjoying the status of being justified by default (e.g. being orthodox); and (3) for an error-possibility to be a serious challenge, there has to be positive evidence that the possibility might be realized in the given situation. It is argued that standard "semantic" versions of contextualism (e.g. those of Lewis, Cohen, DeRose) fail to take these features into account, which makes them overly hospitable to the sceptic, and that Williams' version of contextualism, although incorporating (1), fails to do justice to (2) and (3). According to the contextualism developed here, although epistemic standards vary with the context, the truth-value of particular knowledge-attributions does not. Contexts here are understood as being constituted by two elements: an epistemic practice (a rule-governed social practice such as a scientific discipline, the law, a craft etc., in which knowledge-claims are evaluated according to specific standards) and the "facts of the matter" (i.e. those facts which, together with the epistemic standards in question, determine which error-possibilities are relevant and thus have to be eliminated for a knowledge-claim to be true). If there are several epistemic practices, and thus several contexts, in which a knowledge-claim can be evaluated, it is the "strictest" practice that counts. In this way, the counterintuitive consequence of other versions of contextualism that the same knowledge-claim can be true in one context, but false in another, can be avoided. At the same time, scepticism can be resisted since even in the "strictest" epistemic practices, error-possibilities become relevant only when backed by positive evidence that they might in fact obtain.

Does perception provide us with direct and unmediated access to the world around us? The so-called 'argument from illusion ' has traditionally been supposed to show otherwise: from the subject's point of view, perceptual illusions are often indistinguishable from veridical perceptions; hence, perceptual experience, as such, cannot provide us with knowledge of the world, but only with knowledge of how things appear to us. Disjunctive accounts of perceptual experience, first proposed by John McDowell and Paul Snowdon in the early 1980s and at the centre of current debates in the philosophy of perception, have been proposed to block this argument. According to the traditional view, a case of perception and a subjectively indistinguishable illusion or hallucination can exemplify what is fundamentally the same kind of mental state even though they differ in how they relate to the non-mental environment. In contrast, according to the disjunctive account, the concept of perceptual experience should be seen as essentially disjunctive, encompassing two distinct kinds of mental states, namely genuinely world-involving perceptions and mere appearances. This book presents seven recent essays on disjunctivism first published in two special issues of Philosophical Explorations: An International Journal for the Philosophy of Mind and Action