who has no notion how a bridge is built, or what is the strength of the material used, will demand quite different proofs as to the bearing capacity of the bridge, for he has no confidence in the business. In the first place, it is the critics’ complete ignorance of what is being done which provokes their demand. In the second place, there are the unanswerable theoretical misunderstandings: impossible for us to know them all and understand them all. Just as we find, again and again, in our patients new and astonishing misunderstandings about the ways and the aim of the psychoanalytic method, so are the critics inexhaustible in devising misunderstandings. You can see in the discussion of our conception of the unconscious what kind of false philosophical assumptions can prevent the understanding of our terminology. It is comprehensible that those who attribute to the unconscious involuntarily an absolute entity, require quite different arguments, beyond our power to give. Had we to prove immortality, we should have to collect many more important arguments, than if we had merely to demonstrate the existence of plasmodia in a malaria patient. The metaphysical expectation still disturbs the scientific way of thinking, so that problems of psychoanalysis cannot be considered in a simple way. But I do not wish to be unjust to the critics, and I will admit that the psychoanalytic school itself very often gives rise to misunderstandings, although innocently enough. One of the principal sources of these mistakes is the confusion in the theoretical sphere. It is a pity, but we have no presentable theory. But you would understand this, if you could see, in a concrete case, with what difficulties we have to deal. In contradiction to the opinion of nearly all critics, Freud is by no means a theorist. He is an empiricist, of which fact anyone can easily convince himself, if he is willing to busy himself somewhat more deeply with Freud’s works, and if he tries to go into the cases as Freud has done. Unfortunately, the critics are not willing. As we have very often heard, it is too disgusting and too repulsive, to observe cases in the same way as Freud has done. But who will learn the nature of Freud’s method, if he allows himself to be hindered by repulsion and disgust? Because they neglect to apply themselves to the point of view adopted by Freud, perhaps as a necessary working hypothesis, they come to the absurd supposition that Freud is a theorist. They then readily agree that Freud’s “Three Contributions to the Sexual Theory” is a priori invented by a merely speculative brain which afterwards suggests everything into the patient. That is putting things upside down. This gives the critics an easy task, and this is just what they want to have. They pay no attention to the observations of the psychoanalysts, conscientiously set forth in their histories of diseases, but only to the theory, and to the formulation of technique. The weak spot of