Masochism is studied here in its identity-forming, and thus sexually-differentiated, aim. Viewed as other ways of being a man or a woman, the masculin(izing) masochism of the woman and the femin(izing) masochism of the man emerge from paradox and stand out clearly at crucial times of life: thus in adolescence, masochism is often a mandatory passage on the way to sexual differentiation, sometimes taking the form of initiation, savage or cultural.