Abstract
Timothy Williamson has argued that, unless the speech act of assertion were
supposed to be governed by his so-called Knowledge Rule, one could not explain
why sentences of the form "A and I do not know that A" are unassertable. This paper advances three objections against that argument, of which the first two aim to show that, even assuming that Williamson's explanandum has been properly circumscribed, his explanation would not be correct, and the third aims to show that his explanandum has not been properly circumscribed.