Turiya

Turiya, Sanskrit for the fourth, names a state of consciousness described most concisely in the short Mandukya Upanishad, which maps the syllable Om onto four states of the self: waking consciousness, dreaming consciousness, deep dreamless sleep, and a fourth state, turiya, that underlies and is present within the other three without itself being another content of experience alongside them. The Mandukya describes turiya negatively, not this and not that, as neither inwardly nor outwardly cognitive, neither a mass of cognition nor simple absence of cognition, unseen, ungraspable, without distinguishing marks, the very self that must be realized rather than an object that can be known the way waking experience knows its objects.

Because turiya is described as continuously present beneath the other three states rather than as an additional experience that comes and goes, later Vedantic commentary treats it not as a fourth item on a list but as the unchanging ground of awareness itself, the witness, sakshi, that is present whether the mind is awake, dreaming or asleep, distinguishing turiya sharply from meditative attainments such as samadhi that must be entered and left. Shankara's commentary on the Mandukya, transmitted through his teacher's teacher Gaudapada, treats this identification of turiya with the self as the Upanishad's single most important teaching.

Advaita Vedanta's central teaching about turiya is that it is not achieved but recognized, since on the tradition's account turiya is simply what the self already and always is, obscured from ordinary awareness by identification with the changing contents of waking, dreaming and sleeping rather than absent and needing to be produced through practice. This distinguishes the doctrine sharply from goal states described as attainments, such as samadhi, which a practitioner enters through effort and can subsequently lose; turiya, in the classical reading, cannot be lost because it was never entered in the first place, only overlooked.

Gaudapada's influential commentary on the Mandukya Upanishad, foundational for later Advaita philosophy including Shankara's own teaching, develops turiya into the doctrinal anchor for the claim that the entire apparent world of waking and dreaming experience is, from the standpoint of the fourth state, not other than the one, non dual reality the tradition calls Brahman. Some later yogic and tantric schools use turiya in a related but distinct sense, closer to a special state accessed through practice, a usage Vedantic purists distinguish from the Mandukya's own, stricter meaning.