In Hindu philosophy, turiya (Sanskrit: तुरीय, meaning "the fourth"), also referred to as chaturiya, chaturtha, is the true self (atman) beyond the three common states of consciousness (waking, dreaming, and dreamless deep sleep). It is postulated in several Upanishads and explicated in Gaudapada's Mandukya Karika. Upanishads Turiya as 'the fourth' is referred to in a number of proncipal Upanishads. One of the earliest mentions of the phrase turiya, "fourth," is in verse 5.14.3 of the Brihadaranyaka Upanishad (7th-6th century BCE), referring to a 'fourth foot' of the Gayatri Mantra, the first, second and third foot being the 24 syllables of this mantra: Then there is that fourth (turiya) vivid foot of the Gayatri, which is none other than the sun blazing beyond the sky. The term turiya means the same thing as 'fourth'(caturtha). 'Vivid foot'- for the sunblazes beyond the entire expanse of the sky. A man who knows this foot of the Gayatri in this way will likewise blaze with splendour and fame. According to Raju, chapter 8.7 through 8.12 of the Chandogya Upanishad (7th-6th century BCE) , though not mentioning turiya, 'anticipate' the Mandukya Upanishad and it's treatment of turiya. These verses of the Chandogya Upanishad set out a dialogue between Indra and Virocana, in search of atman, the immortal perceiver, and Prajapati, their teacher. After rejecting the physical body, the dream self, and the dreamless sleep (in which there is no perception of Ï am") as atman, Prajapati declares in verse 12 to Indra that the mortal body is the abode of the "immortal and non-bodily self," which is the perceiver, the one who perceives due to the faculties of the senses. The phrase "turiya" also appears in Maitri Upanishad (late 1st millennium BCE) in sections 6.19 (in the context of yoga) and 7.11: 6.19. Now, it has elsewhere been said: 'Verily, when a knower has restrained his mind from the external, and the breathing spirit (prand) has put to rest objects of sense, there-upon let him continue void of conceptions.