Interest in religion

The Principles completed, James seems to have lost interest in the subject. Creator of the first U.S. demonstrational psychological laboratory, he disliked laboratory work and did not feel himself fitted for it. He liked best the adventure of free observation and reflection. Compared with the problems of philosophy and religion, psychology seemed to him “a nasty little subject” that he was glad to have done with. His studies, which were now of the nature and existence of God, the immortality of the soul, free will and determinism, the values of life, were empirical, not dialectical; James went directly to religious experience for the nature of God, to psychical research for survival after death, to fields of belief and action for free will and determinism. He was searching out these things, not arguing foregone conclusions. Having begun to teach ethics and religion in the late 1880s, his collaboration with the psychical researchers dated even earlier. Survival after death he ultimately concluded to be unproved; but the existence of divinity he held to be established by the record of the religious experience, viewing it as a plurality of saving powers, “a more of the same quality” as oneself, with which, in a crisis, one's personality can make saving contact. Freedom he found to be a certain looseness in the conjunction of things, so that what the future will be is not made inevitable by past history and present form; freedom, or chance, corresponds to Darwin's “spontaneous variations.” These views were set forth in the period between 1893 and 1903 in various essays and lectures, afterward collected into works, of which the most notable is The Will to Believe and Other Essays in Popular Philosophy (1897). During this decade, which may be correctly described as James's religious period, all of his studies were concerned with one aspect or another of the religious question.
His natural interest in religion was reinforced by the practical stimulus of an invitation to give the Gifford Lectures on natural religion at the University of Edinburgh. He was not able to deliver them until 1901–02, and their preparation focussed his labours for a number of years. His disability, involving his heart, was caused by prolonged effort and exposure during a vacation in the Adirondacks in 1898. A trip to Europe, which was to have taken up a sabbatical year away from university duties, turned into two years of invalidism. The Gifford Lectures were prepared during this distressful period. Published as The Varieties of Religious Experience (1902), they had an even greater acclaim as a book than as articles. Cautious and tentative though it was, the rich concreteness of the material and the final summary of the evidence—that the varieties of religious experience point to the existence of specific and various reservoirs of consciousness-like energies with which we can make specific contact in times of trouble—touched something fundamental in the minds of religionists and at least provided them with apologetic material not in conflict with science and scientific method. The book was the culmination of James's interest in the psychology of religion.