Suppose that you ask me what time an upcoming meeting starts, and I say, '4 p.m.' Whenever we make claims like this, we're asserting. If the meeting is really at 3:30 p.m., you'll be late, and probably rather upset that I told you the wrong time. In some sense, it seems like I'm on the hook for having said something false. This sense that I've done something wrong suggests that there are certain standards of evaluating assertions: a way of distinguishing between good and bad, appropriate and inappropriate. We call these standards norms.

This book is about the norms of assertion. Various philosophers have typically attempted to articulate the level of epistemic support required for properly asserting. Some argue, for example, that one must know what one asserts. Others argue that one merely needs to justifiably believe what one asserts–an epistemic standing weaker than knowledge. The purpose of this book is to defend what I propose as the central norm governing our practice of assertion, which I call the Supportive Reasons Norm (SRN).

In rough outline, the standards for warrantedly asserting shift with changes in context, although knowledge is never required for warrantedly asserting. In fact, in some special contexts, speakers may warrantedly lie. This latter feature particularly sets apart my view from others in the debate.