Jung’s theory of psychological types is his most widely known contribution to psychology, forming the basis for the Myers-Briggs Type Indicator and countless other personality assessments. Published in 1921 as Psychological Types, the work emerged from Jung’s attempt to understand fundamental differences in how people perceive reality and make judgments. He observed that people consistently approached life in characteristically different ways. Some oriented primarily toward the external world of people and objects. Others oriented primarily toward the internal world of thoughts and feelings. Some relied on rational judgment. Others relied on perception and experience. These differences were not superficial preferences...