Jung's model of typology is the basis for type tests widly used in business and university, including the Myers-Briggs Type Indicator (MBTI). This book explains in detail Jung's views on the psychological attitudes of introversion and extraversion, the functions of feelings, thinking, sensation and intuition, and the pesky role of the unconscious. Includes an essay by H.K. Fierz, "The Clinical Significance of Extraversion and Introversion."