Mandukya Upanishad and AUM — Complete Teaching in 12 Verses
The Mandukya Upanishad — the shortest major Upanishad at 12 verses — is considered sufficient for liberation by itself, containing the complete Advaita teaching through the analysis of AUM and the four states.
The Mandukya Upanishad (12 verses — the shortest major Upanishad) is considered by Gaudapada (in his Mandukya Karika) to be sufficient by itself to produce liberation. Its teaching: the syllable AUM contains the entire universe; AUM has four elements (A, U, M, and the silence after — corresponding to the four states of consciousness: waking, dreaming, deep sleep, and Turiya); Turiya (the fourth) is the ground of all three states and is Atman/Brahman. The famous declaration (verse 2): 'All this is AUM. All that exists in the three times is AUM. And whatever transcends the three times is also AUM.' The Mandukya's genius is its structural analysis: it maps the entire range of conscious experience (waking, dreaming, sleeping) onto a single syllable (AUM), and identifies the ground of all three states (Turiya/the silence) with the ultimate reality (Brahman). This identification of the ever-present witnessing awareness with Brahman is the complete Advaita teaching in miniature.
All this is AUM — past, present, future, and what is beyond the three times — all this is AUM.
Philosopher John Grimes's analysis of the Mandukya and Gaudapada's Karika in 'Ganapati: Song of the Self' provides one of the most rigorous Western philosophical analyses of the Mandukya teaching, situating its analysis of consciousness states in dialogue with contemporary philosophy of mind.
Mandukya Upanishad