In this paper, I consider how a general epistemic norm of action that I have proposed in earlier work should be specified in order to govern certain types of acts: assertive speech acts. More specifically, I argue that the epistemic norm of assertion is structurally similar to the epistemic norm of action. First, I argue that the notion of warrant operative in the epistemic norm of a central type of assertion is an internalist one that I call ‘discursive justification.’ This type of warrant is internalist insofar as it requires that the agent is capable of articulating reasons for her belief. The idea, roughly, is that when one asserts that p, one is supposed to be in a position to give reasons for believing that p. Bonjour’s reliable clairvoyant Norman, for example, is not in an epistemic position to make assertions regarding the president’s whereabouts—even if Norman knows the president’s whereabouts. In conclusion, I briefly consider whether a type of skeptical argument—often labeled Agrippa’s Trilemma—is motivated, at least in part, by the fact that responses to it violate the relevant epistemic norm of assertion.