Adi Shankara

Shankara's dates are genuinely disputed: the monasteries that trace their lineage to him disagree with each other by over a thousand years, and modern scholarship has mostly settled on the early eighth century, giving him a life so short that its intellectual output looks almost impossible in retrospect. Traditional biographies, more hagiography than history but treasured for what they reveal about how he was remembered, describe a child prodigy in Kerala who mastered the Vedas young, persuaded his widowed mother to let him renounce ordinary life, and then walked the length of India on foot, debating rival schools of thought in public contests with the stakes, in the most famous account, set at nothing less than the loser's whole way of life. His systematic commentaries on the Brahma Sutras, the principal Upanishads, and the Bhagavad Gita built out Advaita, or non-dual, Vedanta into its most influential form: the claim that Atman, the individual self, is not merely similar to but strictly identical with Brahman, the single underlying reality, and that the entire experienced world of separate people, places, and things is maya: not simply illusion in the sense of nothing at all, but a kind of provisional, veiling appearance that dissolves the moment direct knowledge of that underlying identity is realized. He is remembered for a legendary debate with the ritualist scholar Mandana Mishra, judged, according to the story, by Mishra's own formidably learned wife Ubhaya Bharati, who is said to have extended the contest into territory of erotic knowledge Shankara had never studied, sending him off to acquire it by entering the body of a recently deceased king before returning to win. Beyond the legends, his enduring institutional legacy is entirely real: he established monastic centers at the four cardinal points of India, in the south, west, east, and north, each headed by a teacher carrying the title Shankaracharya, and each still functioning today, nearly thirteen centuries after a life some accounts say ended, appropriately for a wandering teacher, in the high Himalayas at Kedarnath rather than anywhere he had ever called home.