Abstract

ABSTRACT Timothy Williamson offers the ordinary practice, the lottery and the Moorean argument for the ‘knowledge account’ that assertion is the only speech-act that is governed by the single rule that one must know its content. I show that these fail to support it and that the emptiness of the knowledge account renders mysterious why breaking the knowledge rule should be a source of criticism. I argue that focussing exclusively on the sincerity of the speech-act of letting one know engenders a category mistake about the nature of constraints on assertion. After giving an analysis of assertion I propose that the norm of a type of assertion is the epistemic state one needs for one’s speech-act to succeed in being an assertion of that type and that the epistemic state in question is determined by the point of the type of assertion. One is practically irrational in violating the norm.