The Varieties of Religious Experience: A Study in Human Nature is a book by the Harvard psychologist and philosopher William James that comprises his edited Gifford Lectures on "Natural Theology" delivered at the University of Edinburgh in Scotland between 1901 and 1902. These lectures concerned the nature of religion and the neglect of science, in James' view, in the academic study of religion. Soon after its publication, the book found its way into the canon of psychology and philosophy, and has remained in print for over a century.

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.

The Moral Equivalent of War, the last public utterance of William James, is significant as expressing the opinions of a practical psychologist on a question of growing popular interest. For the past fifteen years the movement for promoting international peace has been enlisting the support of organizations and individuals the world over. That this is a question on which much may be said for the opposition, James, though a pacificist, admits with his usual fair-mindedness, pointing out that militarism is the sole nourisher of certain human virtues that the world cannot let die, and that until the peace party devises some substitute, some moral equivalent, for the disciplinary value of w...

'Pragmatism' contains a series of public lectures held by William James in Boston 1906–7. James provides a popularizing outline of his view of philosophical pragmatism while making highly rhetorical and entertaining lashes towards rationalism and other competing schools of thought. James is especially concerned with the pragmatic view of truth. True beliefs should be defined as, according to James, beliefs that can successfully assist people in their everday life. This is claimed to not be relativism. That reality exists is argued to be a fact true beyond the human subject. James argues, nevertheless, that people select which parts of reality are made relevant and how they are understood ...

For several years before his death Professor William James cherished the purpose of stating his views on certain problems of metaphysics in a book addressed particularly to readers of philosophy. He began the actual writing of this 'introductory text-book for students in metaphysics,' as he once called it, in March, 1909, and to complete it was at last his dearest ambition. But illness, and other demands on his diminished strength, continued to interfere, and what is now published is all that he had succeeded in writing when he died in August, 1910.