But something happened when I was 17 that shook my safely rationalist worldview and left me with a lifelong puzzle. Years later, I learned that this sort of event is usually called a mystical experience, and I can see in retrospect that the circumstances had been propitious: Thanks to a severely underfunded and poorly planned skiing trip, I was sleep-deprived and probably hypoglycemic that morning in 1959 when I stepped out alone, walked into the streets of Lone Pine, Calif., and saw the world — the mountains, the sky, the low scattered buildings — suddenly flame into life.

There were no visions, no prophetic voices or visits by totemic animals, just this blazing everywhere. Something poured into me and I poured out into it. This was not the passive beatific merger with “the All,” as promised by the Eastern mystics. It was a furious encounter with a living substance that was coming at me through all things at once, too vast and violent to hold on to, too heartbreakingly beautiful to let go of.  It seemed to me that whether you start as a twig or a gorgeous tapestry, you will be recruited into the flame and made indistinguishable from the rest of the blaze. I felt ecstatic and somehow completed, but also shattered.