While the man has a 'hard on,' the woman 'gets wet'; there is in the very word infantile memories of the wet bed, of the guilty and involuntary desire to urinate; man has the same disgust for his nocturnal unconscious wet dreams; projecting a liquid, urine or sperm, is not humiliating: it is an active operation; but there is humiliation if the liquid escapes passively since the body then is no longer an organism, muscles, sphincters, and nerves, commanded by the brain and expressing the conscious subject, but a vase, a receptacle made of inert matter, and the plaything of mechanical caprices.