In this thesis, I propose and defend a theory according to which committing oneself to knowing the proposition expressed counts as an assertion of that proposition. A consequence of this view is the knowledge account of assertion, according to which one asserts that p correctly only if one knows that p. In support of this approach, I offer a strategy of identifying an assertion’s “normative consequences”, types of act that normally take place as a result of one’s making an assertion (...) incorrectly. I outline two such phenomena: retraction and disavowal of knowledge. In continuation, I put the theory to test and critically examine four sets of objections against it, arguing that it can convincingly defuse them. Finally, I discuss two related issues: I maintain that by performing “aesthetic assertions” one also normally performs a non-assertoric speech act of recommendation, and argue for the possibility of “non-linguistic assertions”, whose content is expressed by gestures in appropriate contexts. (shrink)