Abstract
Like many of his medieval successors, Peter Abelard offers principles for ranking sins. Moral Self-knowledge, after all, requires that we recognize not just our Sinfulness, but also the extent of our offense. The most important distinction among sins is that between venial and mortal sins: venial sinners show less contempt and may also be victims of bad moral luck, and so they are far less blameworthy. However, the subjective principle which Abelard uses to protect the venial sinner from blame appears to have absurd consequences: some agents whom we intuitively find saintly turn out to be mortal sinners, while other agents whom we intuitively judge wicked turn out to be mere venial sinners. I argue that Abelard suggests promising replies to these objections, but these replies themselves depend on controversial views about moral psychology.