जाग्रत्स्वप्नसुषुप्तभेदे तुर्याभोगसंभवः (sūtra I.7)
Different states of consciousness are being discussed in this sūtra. Jāgrat is the active state of consciousness; svapna is the dreaming state and suṣupta is the deep sleep state; bheda means division, part, portion, etc.; turya is the fourth state of consciousness, situated right in the middle of the normal states of human consciousness as their Witness; ābhoga means ecstatic experience;sambhava means production. Thus, this sūtra says that the delight of the fourth state of consciousness (turyaabhoga), exists in the other three states of normal human consciousness as the witnessing consciousness.
The first three states of human consciousness happen only one at a time. The aspirant is either active or sleeping with dreams or having sound sleep without any dreams. These three cannot exist all at the same time and can happen one after another. But the fourth state of consciousness turyaprevails in all the three states viz. active, dream and deep sleep states. Without turya, the first three types of consciousness cannot even exist. The highest level of Śiva consciousness is experienced in the state of turya in the form of rapturous light that prevails in all the lower three states of consciousness, when the aspirant is able to unite his individual consciousness with Supreme Consciousness through proper method, known as upāya. The highest state of consciousness has been explained as Udyamo Bhairavaḥ (sūtra I.5).
When spiritual transformation happens in an aspirant, there is a meeting point between the material awareness and the spiritual awareness. Beginning from that point, when the upward movement in the spiritual path really begins, one’s ego begins to be transformed. When ego begins to be realized as Śiva assuming contraction, it leads to universal attitude of the soul, when the knowledge of the omnipresent nature of the Brahman begins to unfold. This is what is to be precisely practiced in meditation. The fourth stage of consciousness continues to prevail in the other three mundane stages of consciousness, as one is bound by ajñāna (ignorance) and consequent egotism. When ego begins its transformation, the grip of ajñāna begins to get loose, paving the way for the realisation of the Self. This transformation happens in the stage of turya.
Turya state is un-inferable, inconceivable and indefinable. Realizing turya is realization of Śiva. It is the Ātman, who is known as Śiva in Trika philosophy. In the case of a fully awakened yogī, the highest level of consciousness prevails predominantly in his active state, and when such a yogī goes around, he spreads the luminosity of Śiva all-round. When the fire is lit by someone, everyone around the fire is benefited by the fire, not merely the one who lit the fire. In the same way, not only the yogī is benefited, but also everyone around him, who are seriously interested in seeking Śiva.
The fourth state of consciousness is always present in all the men as a witness in all the three mundane levels of consciousness. This is in contrast to the first three level of consciousness that prevails one at a time. When one is awake, he cannot sleep, when one is dreaming he cannot be awake and when one is in the state of deep sleep, he can neither be awake nor dream. But, turya is present in the three states of consciousness, sheathed by āṇavamala (Māyā is secondary in Triká,because she is a by-product of āṇavamala), thereby making it unrealizable. This can be realised only in the advanced stages of meditation. Preliminary stages of meditation merely formulate groundwork and lay proper foundation for the realisation of Śiva. If the foundational consciousness is weak, the most powerful Śiva cannot manifest Himself. When proper preparatory work is completed, turyatakes over the usual consciousness, and the emancipation happens thereafter. It does not mean that his body ceases to exist (death), but his consciousness is made ready by his preparatory work, making it easier for turya to reveal itself. He still experiences the three common stages of consciousness, the exception being that the quality of his consciousness has undergone complete transformation and everything is perceived as one with Śiva.