Camille Bos in a suggestive essay ("Du Plaisir de la Douleur," _Revue Philosophique_, July, 1902) finds the explanation of the mystery in that complexity of the phenomena to which I have already referred. Both pain and pleasure are complex feelings, the resultant of various components, and we name that resultant in accordance with the nature of the strongest component. "Thus we give to a complexus a name which strictly belongs only to one of its factors, _and in pain all is not painful_." When pain becomes a desired end Camille Bos regards the desire as due to three causes: (1) the pain contrasts with and revives a pleasure which custom threatens to dull; (2) the pain by preceding the pleasure accentuates the positive character of the latter; (3) pain momentarily raises the lowered level of sensibility and restores to the organism for a brief period the faculty of enjoyment it had lost. It must therefore be said that, in so far as pain is pleasurable, it is so only in so far as it is recognized as a prelude to pleasure, or else when it is an actual stimulus to the nerves conveying the sensation of pleasure. The nymphomaniac who experienced an orgasm at the moment when the knife passed through her clitoris (as recorded by Mantegazza) and the prostitute who experienced keen pleasure when the surgeon removed vegetations from her vulva (as recorded by Féré) took no pleasure in pain, but in one case the intense craving for strong sexual emotion, and in the other the long-blunted nerves of pleasure, welcomed the abnormally strong impulse; and the pain of the incision, if felt at all, was immediately swallowed up in the sensation of pleasure. Moll remarks (_Konträre Sexualempfindung_, third edition, p. 278) that even in man a trace of physical pain may be normally combined with sexual pleasure, when the vagina contracts on the penis at the moment of ejaculation, the pain, when not too severe, being almost immediately felt as pleasure. That there is no pleasure in the actual pain, even in masochism, is indicated by the following statement which Krafft-Ebing gives as representing the experiences of a masochist (_Psychopathia Sexualis_ English translation, p. 201): "The relation is not of such a nature that what causes physical pain is simply perceived as physical pleasure, for the person in a state of masochistic ecstasy feels no pain, either because by reason of his emotional state (like that of the soldier in battle) the physical effect on his cutaneous nerves is not apperceived, or because (as with religious martyrs and enthusiasts) in the preoccupation of consciousness with sexual emotion the idea of maltreatment remains merely a symbol, without its quality of pain. To a certain extent there is overcompensation of physical pain in