American psychologist and philosopher.
William James (January 11, 1842 – August 26, 1910) was a pioneering American psychology and American philosophy who was trained as a physician. He wrote influential books on the young science of psychology, educational psychology, psychology of religion experience and mysticism, and on the philosophy of pragmatism. He was the brother of novelist Henry James and of diarist Alice James. In the summer of 1878, James married Alice Gibbens.

William James was born at the Astor House in New York City. He was the son of Henry James Sr., an independently wealthy and notoriously eccentric Swedenborgian theology well acquainted with the literary and intellectual elites of his day. The intellectual brilliance of the James family milieu and the remarkable epistolary talents of several of its members have made them a subject of continuing interest to historians, biographers, and critics.

James interacted with a wide array of writers and scholars throughout his life, including his godfather Ralph Waldo Emerson, his godson William James Sidis, as well as Charles Sanders Peirce, Bertrand Russell, Josiah Royce, Ernst Mach, John Dewey, Macedonio Fernández, Walter Lippmann, Mark Twain, Horatio Alger, Jr., Henri Bergson and Sigmund Freud.