Psycho-analytic work has shown us that it is precisely these frustrations of sexual life which people known as neurotics cannot tolerate. The neurotic creates substitutive satisfactions for himself in his symptoms, and these either cause him suffering in themselves or become sources of suffering for him by raising difficulties in his relations with his environment and the society he belongs to. The latter fact is easy to understand; the former presents us with a new problem. But civilization demands other sacrifices besides that of sexual satisfaction.