The first time I heard about the jhanas, they sounded too good to be true. These special mental states are described in the sacred texts of an ancient school of Buddhism. Today, advanced meditators usually access them by concentrating on something: a flame, their breath, the sense of loving kindness. The meditators unclench their minds bit by bit, until they reach a state of near-total absorption. If they direct that focus in just the right way, a sequence of intense experiences ensues, beginning with bliss and ending with full-body peace. The jhana bliss state is not like the little uptick in well-being that comes with mindfulness meditation. It is not like a runner’s high. “This stuff is really powerful,” says Matthew Sacchet, the director of the Meditation Research Program at Harvard Medical School. An orgasm is said to be tame by comparison. Tears of joy will sometimes stream down a meditator’s face. The early Theravada Buddhists put no restrictions on the jhanas, but some later traditions taught that they were extraordinarily difficult to attain. Over …