The reader who attempts to evaluate this book will find it necessary to examine it with reference to the "cultural science" movement in contemporary German psychology. For in line with that movement, a rationale which places great emphasis on epistemological issues is developed for "understanding" as opposed to "explanation" as the end of psychologic analysis. To gain the dignity of antiquity, the author meticulously traces the various steps by which modern psychology has in his opinion been derived from the seventeenth century teachings of Descartes. Of the several branches of the "cultural science" movement, Straus is probably most clearly identified with the existential school. The point of view of this school has been characterized on the positive side by a body of quasiphenomenological concepts and on the negative side by a lack of any distinctive methodology. The author attempts to minimize the lack of method by showing that pavlovian "conditioning"