James, William. 1902. The Varieties of Religious Experience: Being the Gifford Lectures on Natural Religion delivered at Edinburgh in 1901-1902. Garden City, NY: Dolphin Books, Doubleday & Company.
To try to make sense of the religious fanaticism that either inspires or serves as a pretext for so much of the violence and destruction we are watching at this moment, I turned to this book, which I had long intended to read. It has been a great pleasure to be in the company of such a rational, good-willed and articulate thinker for nearly 500 pages. I was interested in the subject matter, and amazed by many of the examples he quotes of extreme religious devotion (though the quoted passages are sometimes too tediously extensive), but most of all I was interested in his method. He was working out a way to think rationally about irrational, or supra-rational, experiences.
With a very courteous acknowledgement of "[a]n American philosopher of eminent originality, Mr. Charles Sanders Peirce," he adopts Peirce's name for the method, pragmatism, and paraphrases Peirce's 1878 article laying out its principles. (For a summary of Peirce's thought, see Wikipedia article, Charles Sanders Peirce).
I won't try to summarize the entire book here. That job's well done in the James link below. James is not at all a conventional church-going believer, and confesses that he has no gift for any mystical experience at all. However, unlike such uncompromising atheists as Richard Dawkins (scroll down to 2005/09/25) or Daniel Dennett, he respects the authentic (i.e., not play-acting) prophets and mystics as possessors of a kind of "truth," one which is irrefutably true for them: Santa Teresa, San Juan de la Cruz, George Fox, Joseph Smith, Luther, Gautama Buddha, Mohammed and many others (including the seer I took as my guide during my own, fortunately brief, adolescent religious crisis, Mary Baker Eddy). However, the felt truth of these experiences (visions of God, for example) does not mean they should be accepted as true by anyone who has not personally had them. "The gods we stand by are the gods we need and can use, the gods whose demands on us are reinforcements of our demands on ourselves and on one another," he writes in the 14th lecture, "The Value of Saintliness." (p. 303)
He separates the question of the source of religious vision, which may be anything from an epileptic fit (e.g., St. Paul) to herbal intoxication or simply deep inward reflection, from its "truth," by which he means something like its practical utility. He quotes extensive psychological research (in particular, the studies of a Dr. Starbuck in California) to affirm that "conversion" is an almost universal experience of adolescence, because it is psychologically necessary. By conversion he means a turning away from the chaotic and contradictory messages that assail every young person to find some "process of unification of the self" which always brings "a characteristic sort of relief; and never such extreme relief as when it is cast into the religious mould. Happiness! happiness! religion is only one of the ways in which men gain that gift." (p. 163)
That's because the conversion need not be toward religion. "The new birth may be away from religion into incredulity; or it may be from moral scrupulosity into freedom and license; or it may be produced by the irruption into the individual's life of some new stimulus or passion, such as love, ambition, cupidity, revenge, or patriotic demotion." (163-164) Whatever works for you. For many of us, and apparently for James himself, the "new birth" was into incredulity, i.e., non-believing in a deity. Although James retained some doubt (see his "Conclusions"). After all, his father was a noted Swedenborgian philosopher.
But James is concerned not only about the utility of religious experience for the individual believer, but also about its social utility, its consequences for human society generally. While his language is not entirely clear here, it appears that he does not accept as pragmatic "truth" the kinds of religious sentiment that he calls extreme "Devoutness." "When unbalanced, one of its vices is called Fanaticism. Fanaticism is only loyalty carried to a convulsive extreme. ... The Buddha and Mohammed and their companions and many Christian saints are incrusted with a heavy jewelry of anecdotes which are meant to be honorific, but are simply abgeschmackt and silly, and form a touching expression of man's misguided propensity to praise. ... An immediate consequence of this condition is jealousy for the deity's honor." (310-311) Which leads to such absurdities as the riots over Danish cartoons, or Alabama Chief Justice Roy Moore's placement of the 2.6-ton granite monument of the Ten Commandments in the state building.
I think James was right to respect the personal truth of serious religious believers, and equally right to insist that their truth need not be anybody else's and certainly should not be imposed on anyone. We all have "spiritual" needs, he thinks -- that is, we need some way to put together our otherwise fragmenting "self."(James' notion of "self" seems to anticipate Dennett's formulation of it as "the center of narrative gravity.") But we don't all need to do it the same way. A coherent atheism, or a "healthy-minded" optimism, or a born-again union with the One, are equally valid ways to achieve the "gift" of "happiness," or integration of the self. Whether they are equally good or not depends on their consequences, not only for ourselves individually but in our actions on behalf of others. Makes sense to me.
For more on James and his writings, see William James in the Stanford Encyclopedia of Philosophy.
And don't neglect the sad story of Alice James, which helps us understand the milieu in which her famous brothers William and Henry were working.