Alfred North Whitehead put it best: William James is “that adorable genius.” The Varieties of Religious Experience is not his best book”although there is matter for delight on every page”but it is our best book about religious experience, our best defense against skeptics, and our surest incitement to a genuine public dialogue about the significance of personal religious experience for our common life.

The Varieties is the text of James’ Gifford Lectures on Natural Religion, delivered in 1901 and 1902 at the University of Edinburgh. Already suffering from the heart problem that would take his life in 1910, James was nearly done in by the effort of collecting the two hundred personal narratives that make the work a thick stew of “facts of experience” rather than a genteel consommé of philosophical speculation.

Partly an act of filial piety (James was conscious of having underestimated the spiritual impulses of his Swedenborgian father, Henry James, Sr.), the work was also a continuation of his study of unusual states of consciousness (in The Principles of Psychology and the Lowell Lectures on “Exceptional Mental States”), a sequel to the 1896 lecture on “The Will to Believe” in which James championed the legitimacy of religious belief against W. K. Clifford’s naysaying, and an early manifesto for the pragmatism that is (for better or worse) the quintessentially American contribution to philosophy.

James begins the Varieties by clearing away intellectual obstacles. In his own day, it was fashionable to explain religious excitability as a form of autointoxication brought on by disordered digestion or nerves. (One thinks of Scrooge telling Marley, “There’s more of gravy than of grave in you.”) “Medical materialism,” as James calls it, “finishes up St. Paul by calling his vision on the road to Damascus a discharging lesion of the occipital cortex, he being an epileptic . . . . Carlyle’s organ“tones of misery it accounts for by a gastro“duodenal catarrh.” As the founder of the first psychology laboratory in America, an anatomist, and a sufferer from neurasthenia himself, James would be the last to deny the importance of physiological factors. But, humane Darwinist that he is, he is unwilling to discount mystical insights, whatever their source: “For aught we know to the contrary, 103 or 104 degrees Fahrenheit might be a much more favorable temperature for truths to germinate and sprout in than the more ordinary blood“heat of 97 or 98 degrees.”

Today one is more likely to hear religious experience explained as the product of changing cultural fictions about gender, power, and selfhood; but the principle is the same. After one has counted up all the predisposing factors, James tells us, the real work of interpreting religious experience has just begun.

My students love the Varieties because they hear James making personal experience the arbiter of truth, rejecting institutions and dogmas, transforming religion into therapy, and indiscriminately validating everything from astrology to zazen. This is a common misreading of the Varieties for which James himself is partly to blame. He delineates his subject as “the feelings, acts, and experiences of individual men in their solitude, so far as they apprehend themselves to stand in relation to whatever they may consider the divine,” and ends his lectures by observing that “the axis of reality runs through the egotistic places.” He delights in crackpot visionaries and defends their claims against more sober academic theologians, the “closet naturalists of the deity.” He draws a convincing picture of conversion experiences in which grace suddenly supervenes upon despair (psychologically interpreted as a gift from our “extra“marginal” consciousness), thus making sin and redemption plausible to a generation that knows only addiction and recovery. He is so warmly sympathetic toward the religious testimonies he presents”from the relentlessly cheerful affirmations of the mind“cure movement to the metaphysical reveries of nitrous oxide mystics”that one can miss his criticisms.

But the criticisms are there. James indicts the “religion of healthy“mindedness””grandpa to the New Age”for its shallowness in denying the reality of evil. He points out that the merely interruptive peak experience yields no spiritual benefit. Indeed, the whole of the Varieties is an exercise in the art of testing the spirits. Drawing upon Jonathan Edwards’ Treatise on Religious Affections , and thus inheriting a tradition of discernment that goes back to Cassian and the desert fathers, James proposes evaluating religious experience by its “fruits for life,” taking as our criteria “immediate luminousness, . . . philosophical reasonableness, and moral helpfulness.”It was from the Varieties that Bill W., cofounder of Alcoholics Anonymous, learned not to put too much stock in his mystical “hot flash,” but to emphasize instead the lifelong process of conversion within a fellowship.

The Varieties ”with its individualism, privatism, and subjectivism”has been read as a catalogue of all that is wrong with our culture. But James’ brand of individualism is very different from our own. It presupposes a more robust sense of intellectual and cultural community than most of us have experienced. James sees himself as a public philosopher whose mission in the Varieties is “to redeem religion from unwholesome privacy, and to give public status and universal right of way to its deliverances.” He is a genius at friendship and at no“holds“barred argument, waging decade“long battles with Royce, Bradley, Pierce, and others without losing their goodwill and love. If we could hold such arguments today, then we would know that we were well on the way to a cure for our cultural disintegration and anomie.

James fails to appreciate fully ecclesial forms of faith, but at least he never definitively rules them out. His great contribution is to make religion a live option for those estranged from traditional faith. Never at home in the Christianity of his ancestors, James nonetheless manages in the Varieties to keep the door open for orthodoxy, for supernaturalism, for moral conviction, and for the kinds of religious engagement that make a real difference in the public square.

Carol Zaleski teaches philosophy of religion at Smith College.