Who Controls Your Cortex? Michael Pollan's new book portrays Timothy Leary as a reckless self-promoter, but Leary asked the right questions about psychedelics.

• Author: Sullum, Jacob
• Position: BOOKS - How to Change Your Mind - Critical essay

ON A SATURDAY night in July, I swallowed a tiny square of paper containing about 100 micrograms of LSD and took a walk on the Las Vegas Strip. On the way back to my hotel, the garish lights suddenly seemed lovely. I stopped short, a beatific smile on my face. "America is awesome!" I thought, enchanted by the economic freedom and entrepreneurial energy that had created this entertainment mecca. Surrounded by roving packs of bros and bachelorettes, I resisted the urge to pass judgment on the tastes and preferences of the people who flock to Las Vegas from all over the world in search of a good time. The main point was that they mostly had found what they were looking for, whatever that might be, which is no small thing in a life that is too short and too serious.

Even as I was thinking these deep thoughts, I recognized their banality, but I still felt their truth in a way I never had before. As the journalist Michael Pollan notes in How to Change Your Mind, making familiar insights seem new again is one of the favors psychedelics can do for us.

"Platitudes that wouldn't seem out of place on a Hallmark card glow with the force of revealed truth," he writes. "The mystical journey seems to offer a graduate education in the obvious. Yet people come out of the experience understanding these platitudes in a new way; what was merely known is now felt, takes on the authority of a deeply rooted conviction."

My acid-washed walk in Las Vegas pales beside the ego-dissolving, world-shaking, life-shaping experiences with LSD, psilocybin, toad venom, and ayahuasca that Pollan describes. But all these journeys illustrate the power of certain chemicals to take us out of ourselves, disrupt our mental habits, and help us reach a new understanding of the world and ourselves. The question raised by Pollan's book, which tracks psychedelics from initial mainstream enthusiasm through a prohibitionist backlash and into a scientific rediscovery of their value, is who should control that power and toward what end.

TIMOTHY LEARY, THE Harvard psychologist turned psychedelic guru, had a pretty clear answer to that question. "Who controls your cortex?" Leary and his collaborator Richard Alpert (later known as Ram Dass) wrote in a 1962 letter to The Harvard Crimson announcing their plans to study psychedelics under the auspices of a newly formed International Federation for Internal Freedom. "Who decides on the range and limits of your awareness? If you want to research...