Justification and the authority of norms

What features does a norm have to have such that we really ought to follow it? This paper argues that norms are authoritative when they are justified in a particular sense. However, this brand of justification is not any of those with which we are currently familiar. The authority of norms is not a matter of moral, epistemic or prudential justification. It depends instead on what I call "justification simpliciter." The concept of justification simpliciter is defined and defended in this paper.