William James (1842-1910) was the most influential American psychologist of his era. His masterwork, The Principles of Psychology (1890), remains one of the most cited and quoted works in psychology's history. Written over twelve years, it covered the full range of mental life with extraordinary literary skill and psychological insight. James's functionalist approach — asking what mental processes do rather than what they are made of — profoundly shaped American psychology.
Key Contributions
James's writings anticipated numerous modern concepts. His description of the "stream of consciousness" recognized that mental life is continuous and dynamic rather than composed of discrete elements. His analysis of attention distinguished between active (voluntary) and passive (involuntary) attention, foreshadowing the endogenous/exogenous distinction. His theory of habit as the "flywheel of society" anticipated modern research on automaticity. His distinction between primary memory (what is currently in consciousness) and secondary memory (stored knowledge) preceded the short-term/long-term memory distinction by decades.
James's theory of emotion (independently proposed by Carl Lange) held that emotional experience is the perception of bodily changes: "we feel sad because we cry, angry because we strike, afraid because we tremble." While the simple version is too extreme, modern research on embodied emotion, somatic markers (Damasio), and facial feedback supports the core insight that bodily states influence emotional experience. James was asking the right question — what is the relationship between body and emotion — even if the full answer is more complex than he proposed.