William James (1842 – 1910) was a pioneering American psychologist and philosopher. He wrote influential books on the young science of psychology, educational psychology, psychology of religious experience and mysticism, and the philosophies of pragmatism and Radical Empiricism.

Essays in Radical Empiricism is a collection edited and published posthumously by his colleague and biographer Ralph Barton Perry in 1912. It was assembled from a collection of reprinted journal articles published from 1904–1905 which James had deposited in August 1906 at Harvard University, for supplemental use by his students.