Turiya is a Hindi term describing a state of absolute reality, transcending all other experiences and releasing a completely pure consciousness. Turiya is a transcendent state of awakening, and at the same time it is a state that is always present, underlying all other states of consciousness.
Consciousness can be looked at as having three common states. The first state is when the mind is awake, and is called in Sanskrit jagrata. In this state, the subject, a person in the world, interacts with the object that is the physical world. The waking state is what most of us experience in the vast majority of our lives, with our conscious mind interpreting things we see, and processing the material world instant by instant.
The second state of consciousness is that of the dreaming sleep, or svapna. This is when we are asleep, but our minds are still engaging on a conscious level with the mental world. The dreaming sleep is looked at as a corollary to wakefulness, with the conscious mind still interacting with a world directly, albeit the world of sleep. Both jagrata and svapna can be looked at as fundamentally dualistic, with a subject interpreting objects, or an ego-state interacting with that outside of the self.
The third state of common consciousness is that of dreamless sleep, or susupti. In susupti the conscious mind does not appear to be present, as there is no subject interacting with objects. In this sense, susupti is seen as a non-dualistic state of consciousness. It is still said to be conscious, however, because the very recognition that one is not dreaming shows an understanding of the self. Just as saying you did not hear anything in a silent room shows there is someone to be hearing, or saying you did not see anything in the dark shows there is someone to be seeing, so is the recognition that you dreamed nothing looked on as an acknowledgment that there was someone to be dreaming or not dreaming.
In contrast, turiya is looked at as a state of consciousness beyond the three normal states. It is sometimes called simply the fourth state, and is both beneath and above the other three states. Turiya is the embodiment of consciousness itself, not a manifestation of it. It is the totality of everything, and the headwaters from which all consciousness flows. At the same time, turiya is more than simply a concept of everything. It is said in the Mandukya Upanishad that turiya is not that which is conscious of the objective, nor of the subjective, nor of both, nor simply consciousness, nor all sentience, nor all darkness. It is “unseen, transcendent, the sole essence of the consciousness of self, the completion of the world.”
Yogis attempt to fully realize the state of turiya through practice, engaging in sound resonance, breathing exercises, and body forms. Turiya yoga emphasizes a complete freedom, rejecting force and power, and instead embracing the ideal of a universal harmony that one can learn to resonate within.