1. Epistemology: the study of the nature, source, limits, & justification of knowledge Skepticism: doubt that knowledge is possible Taoism: the differentiation of things is relative; all things are really one Chuang Tzu (369-286 BCE) Sextus Empiricus (2 nd Century) Pyrrhonism: we should refuse to make dogmatic claims to know because all knowledge is relative

2. Cartesian Doubt Sense experiences are often wrong I might be wrong about whether I have a body or if there is a world apart from my imagination (it may be a dream) I might be wrong even about whether my reasoning abilities (e.g., 2+3=5) can be trusted (evil genius); so I should suspend judgment René Descartes (1596-1650)

3. Objections to Descartes’ Method of Doubt To think some experiences are wrong is to assume that some are right To doubt everything, we must doubt whether we are truly doubting, and that requires us to assume a public world of language users Limiting knowledge only to what we know with certainty is too restrictive: we often know things not based on indubitable foundations

4. Hume: Skepticism about the External World The continued existence of things apart from our experience cannot be known, for we cannot compare our experience (or self) with anything outside it as its supposed cause Problem of induction: we cannot say that something is probable without assuming that the future will resemble the past –Induction itself is unjustifiable (Strawson)