Turiya

In Hindu philosophy, turiya (Sanskrit: तुरीय, meaning "the fourth") or caturiya, chaturtha, is pure consciousness. Turiya is the background that underlies and transcends the three common states of consciousness. The states of consciousness are: waking consciousness, dreaming, and dreamless sleep.

Turiya is discussed in Verse 7 of the Mandukya Upanishad; however, the idea is found in the oldest Upanishads. For example, Chapters 8.7 through 8.12 of Chandogya Upanishad discuss the "four states of consciousness" as awake, dream-filled sleep, deep sleep, and beyond deep sleep. Similarly, Brihadaranyaka Upanishad, in chapter 5.14 discusses Turiya state, as does Maitri Upanishad in sections 6.19 and 7.11.

Verse VII of the Mandukya Upanishad describes Turiya:

Not inwardly cognitive, nor outwardly cognitive, not both-wise cognitive,
not a cognition-mass, not cognitive, not non-cognitive,
unseen, with which there can be no dealing, ungraspable, having no distinctive mark,
non-thinkable, that cannot be designated, the essence of assurance,
of which is the state of being one with the Self
the cessation of development, tranquil, benign, without a second,
such they think is the fourth. He is the Self (Atman). He should be discerned.

The insight during meditation of Turiya is known as amātra, the 'immeasurable' or 'measureless' in the Mandukya Upanishad, being synonymous to samādhi in Yoga terminology.

Gaudapada (ca. 7th century) was an early guru in the Advaita Vedanta. Gaudapada is traditionally said to have been the grand-guru of the great teacher, Adi Shankara, one of the most important figures in Hindu philosophy. Gaudapada is believed to be the founder of Shri Gaudapadacharya Math, and the author or compiler of the Māṇḍukya Kārikā.

Gaudapada wrote or compiled the Māṇḍukya Kārikā, also known as the Gauḍapāda Kārikā and as the Āgama Śāstra. In this work, Gaudapada deals with perception, idealism, causality, truth, and reality. The fourth state, (turīya avasthā), corresponds to silence, as the other three correspond to AUM. It is the substratum of the other three states. It is, states Nakamura, atyanta-shunyata (absolute emptiness).

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