As the story is told, an eight-year-old Shankara was bathing in the river Purna when a crocodile seized his leg. Certain he was about to die, he called to his mother for permission to renounce the world. She gave it, and the crocodile let go.

By tradition, he had by sixteen written commentaries on the Upanishads, the Bhagavad Gita, and the Brahma Sutras — texts still studied today — arguing that ultimate reality is one undivided consciousness and that ordinary separateness is a mistake in seeing, not a fact of the world.

Tradition has him walking the length of India on foot, debating rival philosophers and founding four monasteries — in the south, west, east, and north — meant to carry the teaching after he was gone. Historians say those institutions' own records help date him, roughly, to the 8th century.

By tradition he died at thirty-two, at Kedarnath in the Himalayas, having handed his teaching to four chief disciples. No historical record fixes the year. What survives is the argument itself, still read by philosophers who don't agree on when he lived.