A storybook in 7 pages
Advaita Vedanta, taught above all by the 8th-century philosopher Shankara, holds that one undivided awareness underlies everything, and that separateness is a mistake in seeing rather than a fact of the world.
Shankara's most repeated teaching image is a rope glimpsed in near-dark and mistaken for a snake. The fright is real, the reaction is real, but the snake never was. He taught that the ordinary world of separate people and things is like that rope: not nothing, but mistaken for something it isn't, out of the same kind of half-light.
Tradition and most scholars place Shankara in the 8th century CE, though some historians argue for dates closer to 700, based on which earlier philosophers he responds to. The debate has never been settled, but it hasn’t slowed how widely he is read.
Rather than describe ultimate reality directly, which language can't really do, Shankara's commentaries repeatedly use a method older than him: neti neti, 'not this, not this.' Body, no. Thoughts, no. Feelings, no. Whatever a student clung to as 'self,' he pushed it aside, one denial at a time, until only what was doing the looking remained.
Before Shankara, a philosopher named Gaudapada wrote the earliest surviving systematic defense of nondualism, using an argument about dreaming: what felt completely real while asleep dissolves on waking, without ever having truly existed. Shankara revered Gaudapada as his teacher's teacher, and a commentary on Gaudapada's work is traditionally attributed to him.
Tradition credits Shankara with founding four monastic centers in different regions of India, meant to carry the teaching forward after he was gone. One of them, in the south, kept a relatively continuous record of its line of teachers, a record historians still use to help anchor the argument over when he actually lived.
Advaita's core ideas predate Shankara: Gaudapada shaped them before him, and the Upanishads he commented on are older still. Scholars describe Shankara less as the origin of nondual thought than as its most influential systematizer, the one who took scattered insight and built it into a single, teachable structure that has held for twelve centuries.
The four monasteries he founded are still standing. His commentaries are still read. The rope in the dark is still mistaken for a snake, every day, by people who have never heard his name. That, more than any date, is the measure of what he handed on.
It is yours. Touch the chain.