William James was an American philosopher and psychologist, and the first educator to offer a psychology course in the United States. He is considered to be one of the most influential philosophers of the United States and has been dubbed the "Father of American psychology."

Born into a wealthy family, James was the son of the Swedenborgian theologian Henry James Sr. and the brother of both the prominent novelist Henry James and the diarist Alice James. Trained as a physician, he taught anatomy at Harvard but chose to pursue interests in psychology and philosophy instead.

James's works cover various topics, including epistemology, education, metaphysics, psychology, religion, and mysticism. Among his most notable publications are The Principles of Psychology, Essays in Radical Empiricism, and The Varieties of Religious Experience.

Along with Charles Sanders Peirce, he established the philosophical school known as pragmatism and is recognized as a founder of functional psychology. His philosophical perspective known as radical empiricism has influenced many thinkers, including Alan Watts, W. E. B. Du Bois, Edmund Husserl, Bertrand Russell, Ludwig Wittgenstein, Hilary Putnam, and Richard Rorty.