[Jung] has shown with signal lucidity that each person has a right to live according to his own type, and his presentation of the guiding principles for the recognition of the type is one of the most humanitarian achievements that has become manifest. New York Times This volume is drastically serious, positive, didactic, classic and yet more than stimulating. It is energizing, liberating and recreative. The author shows an amazingly sympathetic and comprehensive knowledge of the introvert of the thinking type, and hardly less for his other types. New York Times ...it has been an astounding phenomenon that a single person could develop such an important dynamic typology with such exhaustive inclusiveness between his 38th and 45th years of life. Jung not only saw the need and the problem but formulated and refined the theory to a point that stands the test of time. Wayne K. Detloff, Psychological Perspectives When I first found Bayne's translation, in 1932, I felt that this was the most important book that I had ever read. Since then, I have found no reason to revise my opinion. Joseph B. Wheelwright, Journal of Analytical Psychology