In interviews, Dr. Martin and other subjects described their egos and bodies vanishing as they felt part of some larger state of consciousness in which their personal worries and insecurities vanished. They found themselves reviewing past relationships with lovers and relatives with a new sense of empathy.

The subjects’ reports mirrored so closely the accounts of religious mystical experiences, Dr. Griffiths said, that it seems likely the human brain is wired to undergo these “unitive” experiences, perhaps because of some evolutionary advantage.

“There’s this coming together of science and spirituality,” said Rick Doblin, the executive director of MAPS. “We’re hoping that the mainstream and the psychedelic community can meet in the middle and avoid another culture war. Thanks to changes over the last 40 years in the social acceptance of the hospice movement and yoga and meditation, our culture is much more receptive now, and we’re showing that these drugs can provide benefits that current treatments can’t.”