How plausible is the Augustinian proposal to interpret human wickedness in terms of perversion? For some, the emphasis on perversion does not take the human's capacities for change seriously enough; it represents a conservative and pessimistic obeisance to obsolete and absolutist beliefs about human nature, beliefs which restrain social experimentation and, therefore, progress. For others, it does not take the human's “naturalness” seriously enough; it reflects a fantastically optimistic delusion about our rectitude, and irresponsibly ignores the fact that we inhabit a world, and possess a nature, that is only partly aligned with our ethical aspirations. For both optimists and pessimists, then, the Augustinian tradition's insistence on sin as “second nature” is not a source of real hope but an expression of despair laced with self-hatred. Can the Augustinian proposal be developed in a way that meets these worries? Indeed it can, and the very evidence which these critics think the most problematic aspect of the Augustinian proposal – namely, its complex anthropology – turns out instead to support it.