Major principles examined include legality, actus reus, mens rea, concurrence, harm, causation, defenses, and proof. It is suggested that while the interpretation and application in practice of the general principles of criminal liability presuppose a moral and political philosophy, the major criminal theorists in Anglo-American legal history (Austin, Holmes, Stephen, Hall, Williams, and others) have supposed that criminal theory can be empirical, scientific, and objective. In this supposition, they have emphasized action, harm, and causation, which seem amenable to empirical analyses, at the expense of moral and political philosophy. It is argued that a revision of criminal theory to include moral and political philosophy, particularly with respect to the notion of harm, would contribute to greater justice. Chapter footnotes, index, and approximately 250 references. (Publisher abstract modified)