In 1962, P. F. Strawson concluded his hallmark essay “Freedom and Resentment” with the remark that a sufﬁciently modiﬁed version of the optimist’s view on moral responsibility is the right one. With this he had in mind that our everyday practice of holding each other morally responsible retains its raison d’eˆtre even if free will as libertarians construe it turns out to be illusory. By his lights, optimists justify this practice solely by its beneﬁcial consequences, while pessimists correctly reject this strategy. A key claim of Strawson’s is that the pessimist’s reaction discloses how deeply rooted our natural reactive attitudes are, and his famous contention is that the metaphysical debate on the issue of free will and moral responsibility should take these attitudes as its point of departure. The quest for a justiﬁcation for holding each other morally responsible can only be understood from within the practice itself, and it is the reactive attitudes that lie at the core of this practice.