Sri Ramana Maharshi
There are five states for the individual. They are: (1) Jagrat, (2)Swapna, (3) Sushupti, (4) Turiya, (5) Turyatita.
Of these the jagrat is the waking state. In it the jiva in the Visva aspect and the Lord in the Virat aspect, abiding together in the eight petals of the Heart lotus, function through the eyes and enjoy novel pleasures from various objects by means of all the senses, organs, etc. The five gross elements which are widespread, the ten senses, the five vital airs, the four inner faculties, the twenty four fundamentals - all these together form the gross body. The jagrat state is characterised by satva guna denoted by the letter A and presided over by the deity Vishnu.
The swapna is the dream state in which the jiva in the Taijasa aspect and the Lord in the Hiranyagarbha aspect, abiding together in the corolla of the Heart-Lotus, function in the neck and experience through the mind the results of the impressions collected in the waking state. All the principles, the five gross elements, the will and the intellect, seventeen in all, together form the subtle body of the dream which is characterised by the rajo guna denoted by the letter U and presided over by the deity Brahma, so say the wise.
The sushupti is the state of deep sleep in which the jiva in the Prajna aspect and the Lord in the Isvara aspect, abiding together in the stamen of the Heart-Lotus, experience the bliss of the Supreme by means of the subtle avidya (nescience). Just as a hen after roaming about in the day calls the chicks to her, enfolds them under her wings and goes to rest for the night, so also the subtle individual being, after finishing the experiences of the jagrat and swapna for the time being, enters with the impressions gathered during those states into the causal body which is made up of nescience, characterised by tamo guna, denoted by the letter M and presided over by the deity Rudra.
Deep sleep is nothing but the experience of pure being. The three states go by different names, such as the three regions, the three forts, the three deities, etc. The being always abides in the Heart, as stated above. If in the jagrat state the Heart is not relinquished, the mental activities are stilled and Brahman alone is contemplated, the state is called the Turiya. Again when the individual being merges in the Supreme it is called the turyatita. The vegetable kingdom is always in sushupti; the animals have both swapna and sushupti; the gods (celestials) are always in jagrat; man has all the three states; but the clear-sighted yogi abides only in turiya, and the highest yogi remains in turyatita alone.
The three states alternate involuntarily for the average man. The last two (turiya and turyatita) are however the results of practice and form clear aids to liberation. Of the other three states (Jagrat, swapna
and sushupti) each one is exclusive of the other two and limited by the conditions of time and space. They are therefore unreal.