The Mandukya Upanishad

 The Mandukya Upanishad—the twelve-verse Vedic masterpiece which Adi Shankaracharya’s paramaguru, Gaudapada, called “the essence of all Vedanta”—outlines four states of consciousness: waking (jagrat); dreaming (svapna); deep sleep (shushupti); and a fourth state (turiya), which is witness to them all. Sages have proclaimed that deep contemplation upon this scripture can itself lead to enlightenment, owing to its philosophical poignancy.

As an individual awareness, we experience the cycle of waking, dreaming and deep sleep; but the ground of this experience, the Mandukya explains, is the supreme consciousness which is beyond and witness to them all. Thus the sages famously propounded, “Atman is Brahman”—meaning the individual soul, when examined, is really the supreme consciousness itself. The focus of the Mandukya Upanishad ultimately is upon AUM. It elucidates how each vibrational segment of this mantra corresponds to one of the four conditions of consciousness, and the silence after the mantra’s utterance corresponding with turiya, the timeless, causeless resting place.