John Gibbons presents an original account of epistemic normativity. Belief seems to come with a built-in set of standards or norms. One task is to say where these standards come from. But the more basic task is to say what those standards are. In some sense, beliefs are supposed to be true. Perhaps they're supposed to constitute knowledge. And in some sense, they really ought to be reasonable. Which, if any of these is the fundamental norm of belief? The Norm of Belief argues against the teleological or instrumentalist conception of rationality that sees being reasonable as a means to our more objective aims, either knowledge or truth. And it tries to explain both the norms of knowledge and of truth in terms of the fundamental norm, the one that tells you to be reasonable. But the importance of being reasonable is not explained in terms of what it will get you, or what you think it will get you, or what it would get you if only things were different. The requirement to be reasonable comes from the very idea of what a genuine requirement is. That is where the built-in standards governing belief come from, and that is what they are.