On the axiom: Principia præter necessitatem non sunt multiplicanda, this kind of ideation is the only possible one. Hence we speak about the effects of the unconscious, just as we do about the phenomena of the conscious. Many people have been shocked by Freud’s statement: “The unconscious can only wish,” and this is regarded as an unheard of metaphysical assertion, something like the principle of Hartman’s “Philosophy of the Unconscious,” which apparently administers a rebuff to the theory of cognition. This indignation only arises from the fact that the critics, unknown to themselves, evidently start from a metaphysical conception of the unconscious as being an “end per se,” and naïvely project on to us their inadequate conception of the unconscious. For us, the unconscious is no entity, but a term, about whose metaphysical entity we do not permit ourselves to form any idea. Here we contrast with those psychologists, who, sitting at their desks, are as exactly informed about the localization of the mind in the brain as they are informed about the psychological correlation of the mental processes. Whence they are able to declare positively that beyond the consciousness there are but physiological processes of the cortex. Such naiveté must not be imputed to the psychoanalyst. When Freud says: “We can only wish,” he describes in symbolic terms effects of which the origin is not known. From the standpoint of our conscious thinking, these effects can only be considered as analogous to wishes. The psychoanalytic school is, moreover, aware that the discussion as to whether “wishing” is a sound analogy can be re-opened at any time. Anyone who has more information is welcome. Instead, the opponents content themselves with denial of the phenomena, or if certain phenomena are admitted, they abstain from all theoretical speculation. This last point is readily to be understood, for it is not everyone’s business to think theoretically. Even the man who has succeeded in freeing himself from the dogma of the identity of the conscious self and the psyche, thus admitting the possible existence of psychic processes outside the conscious, is not justified in disputing or maintaining psychic possibilities in the unconscious. The objection is raised that the psychoanalytic school maintains certain views without sufficient grounds, as if the literature did not contain abundant, perhaps too abundant, discussion of cases, and more than enough arguments. But they seem not to be sufficient for the opponents. There must be a good deal of difference as to the meaning of the term “sufficient” in respect to the validity of the arguments. The question is: “Why does the psychoanalytic school apparently set less store on the proof of their formulas than the critics?” The reason is very simple. An engineer who has built a bridge, and has worked out its bearing capacity, wants no other proof for the success of its bearing power. But the ordinary man,