Mind has got three Avasthas, viz., Jagrat (waking state), Svapna (dreaming state) and Sushupti (deep sleep state).
Jagrat Avastha (waking State)
The individual soul (Jiva) is called awake as long as it is connected with the various external objects by means of the modifications of the mind-which thus constitute limiting adjuncts of the soul-apprehends those external objects and identifies itself with the gross body which is one of those external objects. During waking state, the mind occupies the brain.
Svapna Avastha (dreaming State)
When the mind enters the Hita Nadi, which proceeds from the heart and surrounds the great membrane round the heart, which is as thin as a hair divided into thousand parts and is filled with the minute essence of various colours of white, black, yellow and red, the individual soul or Jiva (ego) experiences the state of dream (Svapna Avastha).
In dream, the senses are thrown off just as you throw off your suit when going to bed. In dream state, the senses are quiet and absorbed in the mind. Mind alone plays during dream. The mind alone operates in a free and unfettered manner. There is no land, no sea, no horse, no elephant in dream; but mind creates everything out of its own body, out of the materials supplied from waking consciousness. The mind itself assumes the various forms of bee, flower, mountain, elephant, horse, river, etc. It is the subject. It is the object as well. The seer and the seen are one.
The objects perceived in dreams are revivals of impressions received in waking state and have an external reality only to the dreamer. When modified by the impressions which the external objects have left, the Jiva sees dreams. Perception takes place through the internal organ called Manas; so it is called "inner perception."
Every man has his own subjective mental world and his own dream-creatures. The dream-creatures of a young lady are her husband and new-born babe. Her mind has two strong mental images, viz., those of her husband and baby. The mental images are strengthened by constant thinking. The dream-creatures of a doctor are his patients, while those of a barrister are his clients.
There is temperamental difference. Some rarely get dreams. A Jnani who has Knowledge of the Self will not have any dream.
The Difference Between Jagrat And Svapna.
The difference between the waking and the dreaming states consists in this, that in the waking condition the mind depends on the outward impressions, while in the dreaming state, it creates its own impressions and enjoys them. It uses, of course, the materials of the waking hours.
In Jagrat state, the objects exist independent of the mind. So, every day you see the same objects as soon as you wake up from sleep. But in dreams, the objects of dream exist only so long as there is mind, so long as the dream lasts, because the dream-creatures are manufactured out of mind only. In dream, mind itself creates the dream-creatures out of the materials supplied by waking experiences with some modifications. When mind drops down to waking state, all dream-objects vanish.
Waking State, A Long Dream
You dream that you are a king. You enjoy various kinds of royal pleasures. As soon as you wake up, everything vanishes. But, you do not feel for the loss because you know that the dream-creatures are all false. Similarly, even in the waking consciousness if you are well established in the idea that the world is a false illusion, you will not get any pain. When you know the real Tattva (Brahman), the waking consciousness also will become quite false like a dream. Jagrat state is only a long dream (Dirgha Svapna). The state of waking consciousness does not exist either in dream or sleep. Therefore, it is illusory. Reality always exists in all conditions or states. Wake up and realise, my child!
Manorajya (building castles in the air), recollection of the events and things of dream, recollection of things long past in the waking state are all Svapna-Jagrat (dreaming in the waking state).
Sushupti Avastha (deep Sleep State)
When the mind enters the Puritat Nadi, the state of deep sleep sets in. In Dridha Sushupti (dreamless sleep), you have a cessation of empirical consciousness. There is no play of the mind in this Avastha (state). There is neither Raga nor Dvesha (attraction or repulsion, like or dislike). The mind gets Laya into its cause. Manolaya (involution of the mind) takes place. There is no play of the Indriyas (organs, senses) too.
This state of profound sleep is not a complete non-being or negative, for such a hypothesis conflicts with the later recollections of a happy repose of sleep. The self continues to exist, though it is bereft of all experiences. The consciousness is continuous. You feel you have existed even during sleep as soon as you are awake. You feel that you exist always. Vedantins build their philosophy around this Sushupti Avastha. This stage gives them the clue to the non-dual state (Advaitic state). A careful study of the three states-Jagrat, Svapna and Sushupti (waking, dreaming and deep sleep)-is of immense practical use for the clear understanding of the Vedanta.
Says Ajata Satru to Gargya in Brihadaranyaka Upanishad (II-i-16): "Where was the spirit whose nature is like knowledge at the time when one profoundly sleeps? When the spirit whose nature is like knowledge thus profoundly slept, then the ether in the midst of the heart, drawing in, together with the knowledge of the senses, slept therein in the ether. When the spirit draws in that (knowledge of the senses), then he sleeps indeed. Thus, life is drawn in, speech is drawn in, the eye is drawn in, the ear is drawn in and the mind is drawn in."
When, on the cessation of the two limiting adjuncts (i.e., the subtle and the gross bodies) and the consequent absence of the modifications due to the adjuncts, the Jiva is in the state of deep sleep, merged in the self as it were, then it is said to be asleep. "When a man sleeps here, then my dear, he becomes united with the Sat; he is gone to his own self. Therefore, they say of him, 'He sleeps (Svapiti), because he is gone to his own (Svamapiti)'." Chhandogya Upanishad)
Sankara observes that the phenomena of duality caused by the action of the mind are present in the waking and dreaming states only, but absent in deep sleep state. In waking and dreaming states, there is the play of the thoughts (and the simultaneous occurrence of names and forms) and hence the world as well. In dreamless sleep, there are no thoughts; and hence, there is no world too. We taste the nature of absolute bliss in dreamless sleep, where a man is cut off from the distracting world. It is the mind (lower Manas) that creates differences, distinctions, duality and separateness. If this mind is destroyed by increasing the Sattva and Ahangraha Upasana, then you will feel oneness everywhere (Sarvatmabhava). This needs continuous and strenuous efforts on the part of the Sadhakas.
Degree Of Consciousness In The Three States
In sleep, some action or other is always going on in your mental or vital being; things happen there and they govern waking consciousness. For instance, some are very anxious to perfect themselves and make a great effort in this direction during the day. They go to sleep and when they rise the next day, they find no trace of the gains of their previous day's efforts; they have to traverse the same ground once again. This means that the effort, and whatever achievement there was, belonged to the mere superficial or wakeful parts of the being, but there were deeper and dormant parts that were not touched. In sleep, you fell into the grip of these unconscious regions and they opened and swallowed all that you had laboriously built up in your conscious hours.
Be conscious. Be conscious of the night as well as of the day. First, you will have to get consciousness, afterwards control. Such of you as remember your dreams may have had this experience that sometimes, even while dreaming, you knew it was a dream; you knew that it was an experience that did not belong to the material world. Once you know, you can act there in the same way as in the material world. Even in the dreaming state, you can exercise your conscious will and change the whole course of your dream experience. And, as you become more and more conscious, you will begin to have the same control over your being at night as you have during the daytime, perhaps even more. For, at night, you are free from slavery to the mechanism of the body. The control over the processes of the body-consciousness is more difficult, since they are more rigid, less amenable to change than are the mental or the vital processes. At night, the mental and vital parts of your being, especially the vital ones, are very active. During the day, they are under check; the physical consciousness automatically replaces their free play and expression. In sleep, this check is removed and they come out with their natural and free movements.
Sushupti And Advaita Nishtha Distinguished
In sleep, the mind is in a subtle state. The Vrittis have also assumed a subtle state. But, in Advaita (Vedantic) Nishtha, there is no mind. There is no universe. The world sinks down in Brahman (Prapanchopasamam)-(Vide Mandukya Upanishad, II-1).
The Supreme Self In The Three Avasthas
The Supreme Self which has four forms, is inside the bodies of all living beings and is known by the names Visva, Taijasa, Prajna and Turiya. The seat of the Visva is the right eye; within the Manas dwells Taijasa, (Manasyantastu Taijasah-Gaudapada's Karika on the Mandukya Upanishad), while Prajna resides in the ether of the heart. The objects of enjoyment are of three kinds-gross, subtle and bliss itself. Satisfaction is also threefold.
Jagaritasthano Bahishprajnah Saptanga Ekonavimsatimukhah Sthulabhuk Vaisvanarah Prathamah Padah-The first foot of Omkara is Vaisvanara, whose region is the waking state, who has objective consciousness, who has seven limbs and nineteen mouths and who enjoys gross objects." (Mandukya Upanishad, I-3). The objective mind or conscious mind plays in the waking state.
"Svapnasthano'ntahprajnah Saptanga Ekonavimsatimukhah Praviviktabhuk Taijaso Dvitiyah Padah-The second foot of Omkara is the Taijasa, whose region is dream, who has subjective consciousness, who has seven limbs and nineteen mouths and who enjoys subtle objects." (Mandukya Upanishad, I-4). Taijasa is the reflected Chaitanya or consciousness associated with the dream state. Taijasa is the enjoyer of the subtle world. The subjective mind and false ego play in dreams.
"Yatra Supto Na Kanchana Kamam Kamayate Na Kanchana Svapnam Pasyati Tat Sushuptam Sushuptasthana Ekeebhutah Prajnanaghana Evanandamayo Hyanandabhuk Chetomukhah Prajnastritiyah Padah-The third foot of Omkara is the Prajna, whose region is deep sleep, in whom all melt into one, who is a mass of knowledge, who is full of bliss, who enjoys bliss and who is the door (to the two states of consciousness-waking and dreaming). That is the state of deep sleep wherein the sleeper does not desire anything and does not see any dream." (Mandukya Upanishad, I-5). The mind with the Vasanas rests in deep sleep in Mukhya Prana (chief vital air) in the heart. Mukhya Prana means Brahman. All the Vrittis assume a Sukshma state.
The seven limbs are: (i) Heaven (is His head), (ii) Sun (is His eye), (iii) Wind (is His breath), (iv) Akasa (is His waist), (v) Water (is His pelvis), (vi) Fire (is His mouth) and (vii) Earth (is His feet).
The nineteen mouths are: Five Jnana-Indriyas, five karma-Indriyas, five Pranas and four Antahkaranas (Manas, Buddhi, Chitta and Ahankara).