Epistemology

The understanding of knowledge at work, implicitly or explicitly, in much of ancient and modern epistemology is that of knowledge as justified true belief. According to this traditional account (TAK), a subject, S, knows that p if and only if the following three conditions are met: (i) p is true; (ii) S believes that p; (iii) S is justified in, or has adequate evidence for, believing that p. While (i) and (ii) are almost entirely uncontroversial, (iii) lies at the heart of intense controversy. It is generally agreed that (i) and (ii) are not sufficient; knowledge cannot be analyzed as true belief. Suppose S took a medication that causes paranoid delusions. As a result, S believes he is being followed. Suppose further that S's belief happens to be true. There is broad agreement that accidentally true beliefs like that do not count as knowledge. However, what knowledge requires in addition to truth and belief is highly controversial. According to TAK, it is justification.