As a result of the analysts reassurance about the harmlessness of masturbation, the sixteen-year-old patient went on masturbating excessively with great anxiety (as he done before), but took great trouble to prove its harmful effects. Only when he gave up the compulsory masturbation did he cease to believe in its dangers. He wanted masturbation to be a sort of self-castration in order to avoid being castrated by others. Earlier an older friend had reassured him about masturbation, suggesting at the same time that it would be better to give it up. This advice increased his anxiety, in the same way as the analyst's permission did later. Such patients can be helped only by analysis.