Are you God, I asked, phrasing the question as a thought.

God, Jesus, Mary, call me whatever you want.

How can you do these things, move my body like a puppet

The thought-answer came back instantly: I can do anything.

I had been instructed to concentrate on breathing—deeply and slowly; when I did, the shaking would instantly stop and, bathed in a light I had never seen before, I felt a sense of benevolence and well-being. I wanted to get up and hug the people around me, most of them strangers. Suddenly, the chasm between the human sense of self-importance and our true impotence struck me as wonderfully amusing, and I started to laugh. Later, still on the floor, I used my hands like a choir conductor to direct the singing of hymns that was going on constantly around me. My interpretation of the entire six-hour session—the lesson I felt I was being taught—was that it was time for me to wake up, get my act together, and show more love for those closest to me. Despite the initial terror, I concluded that I had been treated mercifully and regarded the experience as positive.

These accounts are typical. All of it—exotic, wondrous imagery, fear, utter annihilation of the ego, the forced encounter with personal issues one would rather not confront, some compelling apprehension of the sacred and the mystical, and the conviction that everything encountered is more real than the floor one stands upon—are commonly reported. But no two drinking experiences are ever exactly the same.

In the growing body of literature about ayahuasca, by far the most comprehensive and illuminating text is Antipodes of the Mind: Charting the Phenomenology of the Ayahuasca Experience, by Benny Shanon, a professor of cognitive psychology at the Hebrew University in Jerusalem. “An entire continent resides inside our mind and Shanon has provided the map,” Narby explains. “His book gives the sense that Western man is still living in the sixteenth century, and the Americas have just been discovered. Westerners have thought that objective knowledge was the only way to know the world seriously. That’s all very well until what you want to deal with is subjective human consciousness. It’s impossible to be objective about the subjective. Consciousness is a first-person experience. It’s like swimming—you’ve got to be wet.”

During the almost six years it took him to write the book, Shanon, an otherwise traditional, Western-trained cognitive scientist now in his sixties, drank the sacred tea more than 100 times and interviewed 178 other users. Many of those interviewed by Shanon told him that taking ayahuasca was the most important event of their lives. His own experiences affected him profoundly. Gradually, he became aware that “what I was actually entering was a school.... The teacher was the brew.” His sessions of intoxication—his word—forced upon him a rigorous self-analysis. “One finds oneself having no other option but to address issues that are often neither easy nor pleasant.” When he started going to Peru and Brazil, Shanon confesses, he was “a “devout atheist.’ When I left South America, I was no longer one.” Ultimately, he writes, scientific investigation cannot unravel the mysteries of ayahuasca: “I am inclined to say that [it] brings us to the boundaries not only of science but also of the entire Western world-view and its philosophies.”

It was a measure of the importance attached to Gonzales v. udv that, marginal though ayahuasca culture is in the United States, the Supreme Court hearing drew the attention of every major and many minor religious and human-rights groups. Among those filing amicus curiae briefs in udv’s defence were the American Civil Liberties Union and organizations representing Baptists, Presbyterians, Evangelicals, Roman Catholic bishops, Jews, Muslims, Sikh Americans, and various independent scholars.

The insuperable hurdle confronting Deputy Solicitor General Edwin Kneedler was the Religious Freedom Restoration Act. It effectively gives objectors a presumptive exemption from laws that violate their religious beliefs. In the language of the act itself, no federal law shall “substantially burden a person’s exercise of religion” unless a “compelling governmental interest” is proven; even then, the law must be implemented in a way that is “least restrictive” to religious practice.