This chapter provides the discussion of the questions raised by the emerging physicalist–objective (PO) model for the reasonable man criterion. It discusses three heads: the reasonable man criterion; the objective test; and the subjective test. The reasonable man criterion is a clear, practical expression of the orthodox model of the transempirical, free and rational agent, with its connotations of extramundanity, at least in the matter of moral decision and action. The justifications for the reasonable man criterion fall into two main groups: the positive arguments, and negative ones such as those that appeal to the dire consequences of abandoning it. The main positive argument for the objective test is that-matters of guilt and innocence are essentially legal or moral matters, not matters for educated opinion or scientific experts on human behaviour to pronounce upon. From the viewpoint of the PO model developed here, the concessions to scientific explanations of human behaviour do not go far enough.