This article, a contribution to the Common Knowledge symposium “Fuzzy Studies,” criticizes a prominent form of philosophical account of rational activity. Rational activity includes actions as varied as kicking a soccer ball and speaking a language. The philosophical accounts examined — which may be called “intellectualist” — share two features: they originate in skeptical doubt about whether what appears to be rational activity really is, and they ascribe knowledge of the norms of her activity to the person doing it. Given their first feature, intellectualist accounts seek to reassure us. But they fail: the phenomenon to which they appeal in explaining rational activity — a person's grasping its norms — itself presupposes such activity. The question whether a person knows the norms of her activity is a central way of organizing the disputes of the last sixty years over whether the humanities are as intellectually legitimate as the sciences. One prominent thing it can mean to call humanities work “fuzzy” is that it is without authoritative method. Critics of the humanities may be understood as insisting that intellectual work is genuinely rational only where the thinker has in view sharply defined norms. Thus, such critics evince the same kind of concern about the legitimacy of literary or historical studies as intellectualist philosophers do about the reality of apparent soccer kicks or meaningful speech. Whatever the merit of these concerns, there is no comfort to be had in ascribing knowledge of the norms of her activity to either the literary critic or the soccer player.