Perceptual knowledge and relevant alternatives

A very natural view about perceptual knowledge is articulated, one on which perceptual knowledge is closely related to perceptual discrimination, and which fits well with a relevant alternatives account of knowledge. It is shown that this kind of proposal faces a problem (the closure problem), and various options for resolving this difficulty are explored. In light of this discussion, a two-tiered relevant alternatives account of perceptual knowledge is offered which avoids the closure problem. It is further shown how this proposal can: (1) accommodate our intuitions about perceptual knowledge and perceptual discrimination in terms of the notion of primary relevance, (2) give an account of how alternatives can be rationally excluded without appeal to perceptual discrimination in terms of the notion of secondary relevance, and (3) deal with the problem posed by inverted Gettier cases, and hence explain what it means to rationally exclude alternatives which are of secondary relevance.