 In both the a priori case and the perceptual case, the acquisition of knowledge seems to require attention on at least some occasions, and in both of these cases that requirement seems to be a practical one. It may be that knowledge of some propositions is required if one’s experience with a gorilla is to provide one with knowledge of the gorilla’s presence (with the propositions here being of a sort that could serve as a major premise in an inference by which one’s perceptual experience was interpreted), but the requirement on gaining knowledge from experience cannot be that one must be bearing such propositions in mind. The same is true in the a priori domain. What is required before an a priori entitlement can be recognized cannot be that one has to entertain some prior knowledge of a proposition from which that entitlement can be deduced. To suppose that occurrent propositional knowledge is what is necessary for such moves would be to embark on the regress set by Lewis Carroll’s tortoise to Achilles (Carroll, 1895). What epistemic move-making requires is not occurrent knowledge of a proposition. The thing that it requires is the right sort of active attention.