abhāva-pratyayālambanā vṛttir nidrā (I.10)
Deep sleep is that state of mind which is based on an absence [of any content].
(Yoga Sūtras, translated by Bryant p. 41)
In the last few months, we have been working our way through Patañjali’s classification of the cittavṛttis, the different types of conscious states that collectively constitute the experiential life of human beings. This month we have reached the fourth and penultimate of the cittavṛttis, nidrā or deep sleep. At first sight, it might seem strange to classify deep sleep as a conscious state at all, since the common view of deep sleep is to see it as a non-conscious state, a welcome break from the challenges facing us in our in our conscious waking life. In Shakespeare’s words, it is “nature’s soft nurse.” Patañjali’s view that deep sleep is a form of conscious experience is, however, a natural outgrowth of his fundamental understanding of consciousness itself. Patañjali was also heir to centuries of inquiry into the nature of deep sleep and dreaming as it relates to the quest for spiritual liberation. Further exploration of the historical context for this sūtra will therefore give us a better sense of its philosophical significance.
Historical overview
The Self-existent One pierced the apertures outward,
therefore, one looks out, and not into oneself.
A certain wise man in search of immortality,
turned his sight inward and saw the self within.
(Kaṭha Upaniṣad, 4.1 translated by Olivelle p.240)
Centuries before the lifetime of Patañjali, Indian philosophers had directed their attention inwards in their quest to find something joyful and permanent beyond the sufferings of earthly existence. The Upaniṣads, which constitute the last portion of the Vedas, the sacred texts of Hinduism, document this search. We see depicted in them a remarkable cast of individuals dedicating their lives to this inward quest for spiritual knowledge.
There is a famous and extraordinary passage in the Chāndogya Upaniṣad (c. eighth century BCE) where Indra (one of the old powerful Vedic Gods) is depicted as a seeker along with other seekers, looking for answers to the problem of suffering. The symbolism here is interesting because it conveys the idea that the philosophy of yoga represents a sea change within the Indian tradition, so that even the old Vedic Gods are portrayed as eager for this new knowledge and are willing to humble themselves to achieve it. The Vedic tradition was all about ritual knowledge, whereas the new teachings of yoga developed in the Upaniṣads focused on a direct first-person experiential knowledge that would offer an escape from the sufferings of earthly existence.
Indra goes deep into the forest, seeking out the sage Prajāpati, coming to him as a humble student. He has to serve Prajāpati as a student, bringing firewood for thirty-two years before Prajāpati even begins to address his questions. Indra wanted to understand the ātman, the deepest Self, by means of which “one obtains all of the worlds.” Prajāpati gives a series of answers to Indra’s question—that the body, that dreams and that deep sleep are the real Self. Indra, upon reflection, comes to see that each of these answers is unsatisfactory, although each of Prajāpati’s answers seems to bring Indra closer to what he is seeking. The state of deep sleep is given as a penultimate answer to Indra’s question, “Where can I find the Self?” In the following excerpt, Indra returns to Prajāpati for further instruction, having realized the limitations of dreaming as a state of consciousness that frees the individual from suffering.
Prajāpati: Maghavan [Indra], didn’t you leave with a contented heart? So, why have you come back? What do you want?
Indra: It is true, sir, that this [dreaming] self does not become blind when this body becomes blind, or lame when this body becomes lame. This self is clearly unaffected by the faults of the body—it is not killed when the body is slain or rendered lame when this body becomes lame. Nevertheless, people do in a way kill it and chase after it; it does in a way experience unpleasant things; and in a way it even cries. I see nothing worthwhile in this.
Prajāpati: It is exactly as you say, Maghavan. But I will explain it to you further. Stay here for another thirty-two years.
[So he stayed for another thirty-two years, after which Prajāpati spoke to him.]
Prajāpati: When one is fast asleep, totally collected and serene, and sees no dreams—that is the self; that is the immortal; that one is free from fear; that is brahman.
[Indra then left, his heart content. But even before he had reached the gods, he saw this danger: “But this self as just explained, you see, does not perceive itself fully as, ‘I am this;’ it does not know any of these beings here. It has become completely annihilated. I see nothing worthwhile in this.” So he returned again carrying firewood in his hands.]
(Chāndogya Upaniṣad 8.10.3 – 8.11.1-2, translated by Olivelle pp. 173-4)
Deep sleep seems closer than dreaming to the liberating consciousness that Indra seeks. Unlike dreaming, one transcends the dualities of worldy existence, and one does not suffer in deep sleep as one can when dreams become nightmares. Indra, however, upon further reflection rejects Prajāpati’s answer and returns for more instruction. Deep sleep seems too diminished a state to constitute ultimate liberation and insight. Prajāpati finally teaches Indra that the Seer is the real Self—the thinker of thoughts, the hearer of sounds, the seer of sights. We can see in these passages from the Chāndogya Upaniṣad the development of ideas that are central to the Yoga Sūtras, specifically the idea of a Self as Seer, revealed in a state that transcends the normal modes of everyday consciousness.
As a result of their pioneering psychological fieldwork, the Upaniṣadic thinkers eventually established a fourfold classification of human conscious states. This became a standard reference point for all later philosophical thinking. The four states are:
(i) waking consciousness
(ii) dreaming consciousness
(iii) deep sleep consciousness
(iv) a fourth liberating state of consciousness (turīya)
The first three states are viewed as everyday states of consciousness, in that every human being will experience these three forms of consciousness as a natural part of life. The fourth and last state is different insofar as it is a state of consciousness that they believed liberated the individual from the sufferings of worldly existence (saṁsāra). It is also different in that this state of consciousness is not guaranteed in the normal course of life, but requires a technology of spiritual practices for its production. The development of yoga was thus closely associated with the idea of there being extraordinary liberating states of consciousness that were attainable, but only through pursuing specialized contemplative practices.
In the western philosophical traditions, different states of consciousness are often measured against the standard of everyday reality. Thus, dreams are considered to be less real than waking consciousness. We “wake up” from a dream to a realm that we consider to have a greater reality. In the Indian philosophical tradition, although this same measure of everyday reality is used to rank the different states of consciousness, they are also measured against a different standard, the reality of liberation. By this standard, dreaming consciousness has more reality than waking consciousness because it resembles more closely the state of liberation—since it is a more creative state of consciousness and less constrained by worldly limitations. Of the three, deep sleep is viewed as having the most reality of all because it transcends the dualities of worldly existence and is a state that is free of suffering. The idea here is that deep sleep, out of the three everyday states of consciousness, most closely resembles liberation, a fact reflected in the succession of answers given by Prajāpati to Indra.
Nidrā (deep sleep) in the Yoga Sūtras
Patañjali’s classification of human conscious states is more detailed in its presentation than the fourfold classification of the Upaniṣads. The three waking states are now analyzed as five different types of cittavṛtti, and the so-called fourth state of liberating consciousness is now a more complex hierarchy of at least seven different types of samādhi states. Yet the Upaniṣadic classification is still an important touchstone. Following the Upaniṣadic tradition, Patañjali distinguishes between two types of sleep, deep sleep (nidrā) and dreaming sleep (svapna). This fourth cittavṛtti, nidrā, refers to deep sleep only. As we will see when we come to examine the last of the cittavṛttis, dreaming is considered to be a type of memory (smṛti).
This is the only one out of the five cittavṛttis where the word vṛtti is used again in the definition. In his commentary, Vācaspati Miśra acknowledges that there may be some disagreement as to calling sleep a vṛtti, hence the need to include the term in the definition. Unlike the other cittavṛttis, sleep seems to be characterized as an absence of mental activity. Vyāsa confirms nidrā as a vṛtti by pointing out that, since we can remember our time asleep, there must have been some mental activity. We say, for example, “I slept well,” or “I slept badly.” We are thus remembering a specific mental state, not just an absence of mental states. As Carrera says in his commentary, “we remember only that which we perceive.” (p. 34) The absence of content in deep sleep consciousness does not therefore imply an absence of consciousness itself.
It is important, however, to discern the deeper reason why Patañjali insists on including deep sleep in his classification of cittavṛttis. You may remember from our study of vikalpa that consciousness is not just an accidental property of puruṣa, but constitutes its very essence. Consciousness is the essential feature of each eternal puruṣa, a feature which it never loses. Since the puruṣa is the enduring part of our existence, so too is consciousness. What is diminished in sleep is the ability of the instruments of cognition to function as a conduit of consciousness, since they are clouded by dullness (tamas). Losing consciousness is not an option for Patañjali. Consciousness is a light that cannot be turned off.
One question is how the quietness of deep sleep compares to that of liberation. In his commentary, B.K.S. Iyengar observes a link between these two states: “sleep gives one a glimpse of the seer.” Spiritual liberation, however, is not to be equated with sleep. As B.K.S. Iyengar goes on to say, it is only an indistinct glimpse, “because the light of discrimination, viveka, is clouded.” (LOYS p. 56) Responding to the question as to how sleep differs from one-pointedness (a higher form of consciousness), Vācaspati Miśra says in his gloss, “… although it is similar to one-pointedness, yet it is caused by Tamas, and is therefore contrary to both the cognitive and ultra-cognitive trances.” (p. 25 Rāma Prasāda). Thus, although deep sleep is a state that transcends the dualities of the material world, a state in which the ego is submerged and also a state in which we escape our suffering, it is a dull state, devoid of the insight of liberation. It is also temporary.
Concluding thoughts
As was the case in many ancient societies, dreaming and deep sleep were regarded as valuable experiences for the individual, offering potential sources of insight and knowledge. It is easy to take these states of consciousness for granted, but they are curious dimensions of our existence. In the absence of a scientific explanation for these states, they must have seemed quite magical. In I.38, Patañjali gives dreams and deep sleep as important tools to be used for overcoming the obstacles faced on the yogic path, for the reasons discussed above, that such states give us some sense of the ultimate goals of the yogic path. Dreams can also be used as a tool for gaining insight into our psyche and the workings of the subconscious mind.
In popular culture, movies like The Matrix bring to life the philosophical worry that so-called reality might not be as real as it seems to us. Long before, philosophers in India too harbored this belief in their rejection of waking consciousness as constituting the last word in what is real for human beings. Just as we have all had the experience of waking up from a dream, they posit a state of liberating consciousness which feels like a “waking up” from what we had previously viewed as real. From the vantage point of spiritual liberation, the so-called reality of waking life seems like a dream and falls away in the face of a new reality.
Joy Laine taught philosophy at Macalester College for over thirty years and teaches Iyengar Yoga around the Twin Cities.
Sources
Edwin Bryant, The Yoga Sūtras of Patañjali. North Point Press, 2009.
Jaganath Carrera, Inside the Yoga Sūtras. Integral Yoga Publications, 2005.
B.K.S. Iyengar, Light on the Yoga Sūtras. Aquarian Press, 1993.
Patrick Olivelle, Upaniṣads. Oxford’s World Classics, 2008.
Rāma Prasāda, The Yoga Darśana of Patañjali. Logos Press, 1912/2005.
