Abstract
This paper offers a critical reconsideration of the traditional doctrine that responsibility for a crime requires a voluntary act. I defend three general propositions: first, that orthodox Anglo-American criminal theory fails to explain adequately why criminal responsibility requires an act. Second, when it comes to the just definition of crimes, the act requirement is at best a rough generalization rather than a substantive limiting principle. Third, that the intuition underlying the so-called “act requirement” is better explained by what I call the “practical-agency condition,” according to which punishment in a specific instance is unjust unless the crime charged was caused or constituted by the agent's conduct qua practically rational agent. The practical-agency condition is defended as a reconstruction of what is worth retaining in Anglo-American criminal law's traditional notion of an “act requirement.”