Richard Foley

An increasing number of epistmeologists claim that having beliefs which are reliable is a prerequisite of having epistemically rational beliefs. Alvin Goldman, for instance, defends a view he calls “historical reliabilism.” According to Goldman, a person S rationally believes a proposition p only if his belief is caused by a reliable cognitive process. Goldman adds that a proposition p is epistemically rational for 5, whether or not it is believed by him, only if there is available to S a reliable cognitive process which if used would result in S’s believing p. Likewise, Marshall Swain, Ernest Sosa, and William Alston all claim that reliability is a prerequisite of epistemic rationality. Swain claims that S rationally believes p only if he has reasons for p which are reliable indicators that p is true. Sosa says S rationally believes p only if the belief is the product of an intellectual virtue, where intellectual virtues are stable dispositions to acquire truths. And, Alston says that S rationally believes p only if the belief is acquired or held in such a way that beliefs held in that way are reliable, i.e., mostly true.

In his 1963 article, “Is Justified True Belief Knowledge?”1 Edmund Gettier devised a pair of counterexamples designed to illustrate that knowledge cannot be adequately defined as justified true belief. The basic idea behind both of his counterexamples is that one can be justified in believing a falsehood P from which one deduces a truth Q, in which case one has a justified true belief in Q but does not know Q. Gettier’s article inspired numerous other counterexamples, and the search was on for a fourth condition of knowledge, one that could be added to justification, truth, and belief to produce an adequate analysis of knowledge