William James

William James was born in 1842 into a wealthy and well-connected family. He received a good education and earned a medical degree from Harvard University in 1869. Fascinated with psychology and philosophy, he would write and teach on both subjects throughout his career as a professor at Harvard. His book Principles of Psychology, published in 1890, established him as an authority in the field, and served as a standard textbook for some time. He continued his academic and intellectual work, focusing mostly on the philosophic system of pragmatism, until
his death in 1910.

James is best known in A.A. for his book Varieties of Religious Experience. Published in 1902, the book is comprised of a collection of talks he delivered in Edinburgh, Scotland, in 1901 and 1902 known as the Gifford Lectures on Natural Theology. As the title suggests, James sought to describe and analyze incidents of religious experiences. The main thesis of this work is that religious experiences, which occur to single individuals, can have objective value, and should be the focus of the study of religion. Moreover, James believed that the experiences he examined offered stronger evidence for the existence of God and the supernatural than more intellectual approaches.

(Mostly from Wikipedia)