The cover of a recent Time magazine special issue features a crafty-looking yoga-babe sitting in padmasana alongside the headline: How Your Mind Can Heal Your Body. It’s just another sign of a sea change in the mainstream representations of mind, as new psychoactives, imaging technologies, and pop spirituality recontextualize the neural dance of consciousness and flesh. The boundaries between consensus reality and altered states, it seems, are getting wavy again.

Enter John Horgan’s Rational Mysticism, a journalistic exploration of edgy mind science that may be, because of its mainstream profile, one of the most important books on psychedelics published in years. A longtime Scientific American contributor, Horgan hit pay-dirt with 1996’s The End of Science, which proclaimed the heretical idea that science was finally winding down, having nearly reached the end of its grand goal of explaining nature. Now that we have worked out the big ideas of quantum physics and relativity, molecular biology and evolution, Horgan argued, science now resembles a well-marketed mop-up operation. While certainly over-stating the main theme, Horgan nonetheless gave voice to the growing sense that science is losing its explanatory power as we hone in on the biggest questions.

Needless to say, Horgan’s book pissed off the labcoat set, who loudly rejoined that huge and crucial areas of reality remain to be studied. The most important, of course, is the source of all this hullabaloo in the first place – in other words, the human mind. What is mind? How does the brain work? And what, pray tell, is the link between them? Even though cognitive science is just beginning, Horgan may still be right, because these questions – because they self-reflectively involve ourselves—are fundamentally different than studying the Burgess shale or the microwave background of the Big Bang. One outcome in the growing interest in consciousness is the return to the mechanics of altered states, which haven’t received much attention since the 1960s and 70s.

With Rational Mysticism, Horgan has set his sites on the most exotic and mythologized altered states of all: mystical experience, which Horgan wisely leaves loosely defined. “The vision may or may not be ineffable, transient, unitive, or blissful, but it must offer some ultimate insight, however strange, paradoxical, and unlike ordinary knowledge.” Erowid readers will be pleased to know that in his quest to understand what mystical experience is and what it has to do with the brain, Horgan ends of up spending nearly half the book on psychedelics. Appropriately, his fascination is rooted in his own experience: a 1981 trip on some “supercharged LSD” that Harvard’s John Halpern suspects was the fabled motherfucker BZ (3-quinuclidin-3-yl benzylate). Though blissing out at points, Horgan wound up with a rather harrowing vision:

Creation – the multiplicity of the world – arises out of God’s terrified confrontation with His own solitude, improbability, and potential mortality. Shunning His existential plight, God dissolves Himself into myriad selves, which compulsively seek but can never quite discover their true nature.

Throughout the book, Horgan is plagued by this question: why did creation happen in the first place, and why are it and us so fucked up? The gnostic answer he got during his trip, and which he brings up during many of his interviews, not only offers further proof that we are indeed locked inside a Phil Dick novel, but inures Horgan from the blissfully pat “all is one” visions of many mystics. At the same time, while keeping his skeptical science journalist hat on, he remains unsatisfied with simple reductionist answers to the Big Questions. Like many of us, he is trying to reconcile mystic intuitions with reason, and while his ponderings can often seem breezy and too quick, they also cut to the chase.

Rational Mysticism basically consists of a series of journalistic profiles of various heavy-weights who offer their different perspectives on the mystic experience. The charming and optimistic Huston Smith is balanced with suspicious deconstructionist scholars. Horgan talks to scientists like the “neurotheologists” Andrew Newberg and Michael Persinger, who believe they are honing in on the portions of the brain that give rise to religious experience. (Horgan finds Persinger and his celebrated “god machine” to be rather lame.) Horgan also visits “the weight-lifting bodhisattva” Ken Wilber, a hardcore meditator who claims to have achieved “undivided nondual consciousness” and whose door-stop books represent perhaps the most thorough and sophisticated contemporary attempt to rationally build an integral map of human knowledge that bridges science, psychology, and mysticism.

Horgan’s self-proclaimed journalistic credo is “No ideas but in people.” That is, he keeps a sharp eye on the dress and manner of his subjects, and is not shy about sharing his personal impressions of their apparent shortcomings and murky motivations. For example, though he was impressed with Wilber’s mystical authority, he found him a somewhat heartless and arrogant person, while Terence McKenna, whose raps he found predictably sketchy, impressed him as an exceptionally warm and funny person in love with the weirdness of the world. Though you are not always sure whether to trust Horgan, I’ve had the occasion to meet a few folks in the book, and I found that his perceptions largely accorded with my own.

Perhaps the most fascinating chapter profiles Susan Blackmore, whose book The Meme Machine argues that free will and the self are just illusions woven by interlocking memes parasiting our brains. Though an arch-skeptic about paranormal matters, Blackmore turns out to have undergone the sorts of out-of-body astral trips that would make New Age shamans out of most of us. She began her career attempting to prove the existence of ESP and other weird phenomenon, but became disillusioned with the psi scene and now preaches a withering reductionism worthy of Richard Dawkins. Still, she practices Zen, and maintains a spiritual view of the world. For Blackmore, genuine mystical experience means awakening from the meme dream, an experience of radical deconditioning that results in a state, simultaneously, of “total aloneness and complete oneness.”

Throughout Rational Mysticism, Horgan wants to show how different people navigate the ambiguous zone between reason and mysticism – or whatever you want to call it—that many of us find ourselves shuttling around these days. This dance between the spirit and the nervous system inevitably leads Horgan to the topic of psychedelics, which takes up the second half of the book. Much of this material will be familiar to Erowid readers, though Horgan provides illuminating personal takes on characters like Christian Ratsch, Franz Vollenweider, Stan Grof, Rick Strassman, the Shulgins, and McKenna.

McKenna’s untimely death brings Horgan back to his meditations on suffering and evil, questions he brings to the Marin County ayahuasca trip that, somewhat predictably, closes the book. It’s a boring trip report, but it does lead Horgan to suggest some links between science and mysticism that, thankfully, do not become yet another stir fry of Hindu metaphysics and quantum mechanics. For Horgan, both science and mystic experience affirm the absurd miracle of existence, the incredibly improbable gift of ordinary life, even in a world of death, anxiety, and spam. The most profound questions are often the simplest. One of the most profound things I ever heard came from my grandfather, Jake Powell, a hard-drinking rascal who never graduated high school and didn’t give a fig for philosophy or religion: “Why is there something rather than nothing?” Science will never answer that question, and mystical insight won’t either. But both modes of exploration can deepen our intimacy with the starry vastness of that query.