Benny Shanon’s The Antipodes of the Mind: Charting the Phenomenology of the Ayahuasca Experience is one of the most compelling books on altered states I’ve read, up there with James’s Varieties of Religious Experience, Huxley’s Doors of Perception (to which Shanon’s title alludes) and PIHKAL and TIHKAL by Ann and Alexander Shulgin. Unlike, say, the psychedelic performance artist Terence McKenna (whose writings I enjoy), Shanon’s authorial persona is earnest, serious, straightforward, absolutely trustworthy. He is a true scientist, dedicated to precise reporting and careful analysis rather than to entertainment.

Not that his book is dull. Far from it. Antipodes is suffused with a sense of genuine adventure, of a kind that has virtually vanished from modern science. Plunging into the depths of his own ayahuasca-intoxicated mind, Shanon resembles one of the great Victorian explorers trekking into uncharted wilds, maintaining his equilibrium and wits even in the face of the most fantastical sights. Like Darwin on the voyage of the Beagle, Shanon is concerned primarily with collecting and categorizing data rather than theorizing. At the end of his book, however, he ponders his and others’ experiences and draws some tentative conclusions. Ayahuasca, he asserts, can be both truth-revealing and “the worst of liars.” Shanon remains skeptical of the occult claims often made for the drug that it puts us in touch with spirits, makes us clairvoyant, lets us leave our bodies and travel astrally. He suggests that ayahuasca visions are products of the imagination rather than glimpses of a supernatural realm existing in parallel to our own. This proposal will sound reductionistic to some, but it is actually quite provocative, and raises many questions requiring further consideration. Why does the imagination, when stimulated by ayahuasca, yield visions so much stranger and more powerful than those we encounter in, say, ordinary dreams? Why do ayahuasca-drinkers from widely disparate cultures so often hallucinate similar phenomena, such as jaguars and snakes, or palaces and royalty? Why are the visions of even an atheist like Shanon so often laden with religious significance?

Antipodes will no doubt be eagerly seized upon by the psychedelic intelligentsia. But it deserves to be read by anyone interested in religion, mysticism, and consciousness—and who is not? It should be required reading for psychologists, psychiatrists, and neuroscientists, because it shows how absurdly simplistic are the biochemical, Darwinian, and genetic models now dominating mind-science. Inner space, Shanon reminds us, truly is the last great frontier of science, and its reaches are vast and wild and strange.