It is certainly possible to make all kinds of objections to the proposition that neurotic symptoms are substitutes for sexual gratifications. I will discuss two of them to-day. If any one of you has himself undertaken the analysis of a large number of neurotics, he will perhaps shake his head and say: “In certain cases this is not at all applicable, in them the symptoms seem rather to contain the opposite purpose, of excluding or of discontinuing sexual gratification.” I shall not dispute your interpretation. In psycho-analysis things are often a good deal more complicated than we could wish: if they had been simpler psycho-analysis would perhaps not have been required to bring them to light. Certain features of the ritual of our second patient are distinctly recognizable as being of this ascetic character, inimical to sexual satisfaction; e.g., her removing the clocks for the magic purpose of preventing erections at night, or her trying to prevent the falling and breaking of vessels, which amounts to a protection of her virginity. In other cases of ceremonials on going to bed which I have analysed this negative character was far more marked; the whole ritual could consist of defensive regulations against sexual recollections and temptations. But we have long ago learnt from psycho-analysis that opposites do not constitute a contradiction. We might extend our proposition and say that the purpose of the symptom is either a sexual gratification or a defence against it; in hysteria the positive, wish-fulfilling character predominates on the whole, and in the obsessional neurosis the negative ascetic character. The symptoms can serve the purpose both of sexual gratification and of its opposite so well because this double-sidedness, or _polarity_, has a most suitable foundation in one element of their mechanism which we have not yet had an opportunity to mention. They are in fact, as we shall see, the effects of _compromises_ between two opposed tendencies, acting on one another; they represent both that which is repressed, and also that which has effected the repression and has co-operated in bringing them about. The representation of either one or another of these two factors may predominate in the symptom, but it happens very rarely that one of them is absent altogether. In hysteria a collaboration of the two tendencies in one symptom is usually achieved. In the obsessional neurosis the two parts are often distinct: the symptom is then a double one and consists of two successive actions which cancel each other.