This is the first English translation of a book written in 1923. In his preface Schilder says that he is attempting to integrate phenomenology, experimental psychology, brain pathology, and psycho-analysis, and in this, to some extent, he succeeds; although he may convince the psycho-analyst of the unity of the whole nervous and psychic apparatus more easily than his other readers.

The book may be divided into two main parts, the first of which is concerned with the theory of perception, action and language, and memory. The