Various specific RA theories differ as to just what ruling out amounts to and what the standard of relevance is—e.g., whether it has to do with “the kind of possibilities that actually exist in the objective situation” (Dretske 1981b, 63; cf. 1981a, 131), or facts about the subject’s psychological/conversational setting (Goldman 1976, 89; 1989, 147). But, insofar as there is some interesting variation in the set of relevant alternatives to a given proposition, we have the possibility of there being a corresponding variation in what it takes to know that p, and so a kind of pluralism here as well.