ABSTRACT
The discovery of the characteristics of the system Ucs. is the most creative and fundamental of Sigmund Freud's discoveries, because it is on the characteristics that his greatest contributions to psychology, especially all those pertaining to dreams, are based. The laws of the system Ucs. could be the consequence of principles of scientific logical system; in any case they would conform to it. The study of schizophrenic thinking shows that it conforms to two definite principles. The first is the representative of conscious normality or, in other words, of a type of thinking identical with scientific thinking; it is not something different from either. The simultaneous operation of both the first and the second principle may frequently be seen in the same mental product. On the other hand, consideration of these principles, especially of the second, reveals that they constitute that aspect or part of schizophrenic thinking which corresponds to the thinking of the system Ucs.
