William James

William James published 'The Principles of Psychology' in 1890, a comprehensive work that is widely considered the foundational text of American psychology. The book introduced concepts such as the 'stream of consciousness' and influenced generations of researchers, philosophers, and writers.

James was one of the principal founders of pragmatism, the distinctly American philosophical movement that judges the truth of ideas by their practical consequences. He elaborated this philosophy in his 1907 book 'Pragmatism: A New Name for Some Old Ways of Thinking,' which became one of the most widely read philosophy books of its era.

James proposed what became known as the James-Lange theory, arguing that emotions arise from our perception of bodily changes rather than causing them. In his famous example, we feel afraid because we run from a bear, rather than running because we feel afraid—a reversal of common intuition that remains debated today.

William James was the older brother of Henry James, one of the most celebrated novelists of the 19th and early 20th centuries known for works like 'The Portrait of a Lady' and 'The Turn of the Screw.' They grew up in the same intellectually vibrant household under their father, Henry James Sr., a prominent theological writer.