The term "contextualism" has been used to denote many different philosophical theories. Within epistemology alone, there are two broad categories of theories that have been called "contextualist": subject contextualism and attributor contextualism.

Subject Contextualism

A few basic concepts are needed to explain subject contextualism. Let S be an epistemic subject, a being whose cognitive attitudes are proper targets of epistemic evaluation. Let C be a cognitive attitude that S has. C may be a belief, a judgment, a high degree of confidence, an affirmation or endorsement of some kind—any attitude that is a proper target of epistemic evaluation. C has a propositional content p. Finally, let x be the situation in which S Cs that p. We will hereafter specify the target of epistemic evaluation as "S's Cing that p in x."

According to subject contextualism, whether S Cs that p in x...