The knowledge account of assertion holds that it is improper to assert that p unless the speaker knows that p. This paper argues against the knowledge account of assertion; there is no general norm that the speaker must know what she asserts. I argue that there are cases in which it can be entirely proper to assert something that you do not know. In addition, it is possible to explain the cases that motivate the knowledge account by postulating a general (...) norm that assertions would be true, combined with conversational norms that govern all speech acts. A theory on which proper assertions must be true explains the data better than a theory on which proper assertions must be known to be true. (shrink)