This volume brings together a collection of essays, many of them scholarly classics, which form part of the debates on three questions central to criminal law theory. The first of these questions is: what conduct should be necessary for criminal liability, and what sufficient? The answer to this question has wider implications for the debate about morality enforcement given the concern that the 'harm principle' may have collapsed under its own weight. Secondly, essays address the question of what culpability should be necessary for criminal liability, and what sufficient? Here, the battles...