Yoga Sutra - Samādhi Pada 1.51
Upon the cessation of even those [truth-bearing saṁskāras], nirbīja–samādhi, seedless meditative absorption, ensues.
We now come to the end of the road of the yogic process outlined by Patañjali. In nirbīja, seedless, samādhi, explains Vyāsa, both the illumined insight and discernment born in sabīja-samādhi and the truth-bearing wisdom saṁskāras that accompany it, are themselves rendered inactive. Vyāsa notes that the nirodha-saṁskāras of I.50, the restraining or suppressing saṁskāras, block or eliminate even these beneficial truth-bearing saṁskāras of discrimination. In the ensuing state of nirbīja-samādhi, the yogī’s awareness has no contact whatsoever with prakṛti, external reality, either in its gross or subtle aspects. In other words, the citta is not focused on any aspect of an object, gross or subtle; completely uncoupled from citta, all mental and cognitive processes, puruṣa is now aware simply of itself. There is a saṁskāra that facilitates this by suppressing all saṁskāras whatsoever, including those of insight and wisdom. This is the nirodha-saṁskāra (as its name suggests, the ultimate saṁskāra that produces absolute citta-vṛtti-nirodha). All thought is now latent, sarva-nirodhān.
Nirbīja-samādhi is different from the asmitā stage of sabīja-samādhi discussed in I.17. In the latter, the consciousness of the puruṣa is still emanating out and being channeled through citta. Because citta is so pure in this state, the commentators compare it to a luminous mirror in which puruṣa can see its own reflection. But puruṣa is not seeing itself directly; it becomes aware of itself indirectly by seeing a reflection of itself through the medium of citta. In nirbīja-samādhi, the consciousness of puruṣa is not radiating out and aware of itself as a reflection in citta, because the citta has uncoupled itself completely from puruṣa, who can now remain purely self-absorbed, that is, no longer aware of prakṛti at all.
The term nirbīja, seedless, indicates that this state is not related to any object that can plant a saṁsāric seed in the citta, not even the nirodha-saṁskāra of the last sūtra. It therefore does not leave any record of itself in the citta. The existence of the nirodha-saṁskāras can therefore be inferred, says Vyāsa, only by the “lapse of time in the nirodha state.” What he means is that when one enters into nirbīja-samādhi, one is not aware of Time, since one has no external awareness of anything prākṛtic at all, and thus, since there is absolutely no frame of reference leaving its imprint on the mind by which one can gauge the passage of Time; one can only infer that one has been in such a state after emerging from it and noticing the amount of Time that has passed since one first sat down to meditate. In other words, if a yogī were to fall into such a meditative state in the morning, he or she would be made aware of it only if, upon coming out of such a state, it were now evening. The yogī, says Vācaspati Miśra, can have no perception or cognition in this state, since all vṛttis, mental functionings, have ceased—the mind is completely inactive. Therefore, there are no cognitive imprints relating to the passage of Time being deposited into the mind as memories of this state as is the case with all other normal or even paranormal activities. This is obviously relevant when considering why there are differences in attempts to describe these states in the various mystic traditions of the world. With no imprints in the mind to recollect, of what categories does the yogī avail in attempting to describe them? Hence the repeated assertions in mystical texts such as the Upaniṣads that this experience of ātman is beyond words, thoughts, and therefore descriptive categories.
Vijñānabhikṣu sees the eradication of all discriminatory or truth-bearing saṁskāras during nirbīja or asamprajñāta-samādhi to be a gradual process, which explains how a yogī can enter into the nirbīja-samādhi state and then return to discriminatory consciousness—the total elimination of all such wisdom saṁskāras is not instantaneous. When they reactivate, one is thrust back into external prākṛtic consciousness. According to Vijñānabhikṣu, only when the very last saṁskāras born of sabīja (samprajñāta-samādhi) are eradicated by the series of nirodha-saṁskāras born of nirbīja (asamprajñāta-samādhi), does one enter fully into the nirbīja state permanently. This points to the death of the physical frame. There thus appears to be a progression even within nirbīja.
To summarize, Vyāsa is suggesting here that for such a total state of internal absorption to occur, there must be a certain type of saṁskāra, the nirodha-saṁskāra, that blocks all cognitive functioning of the citta, even the hitherto beneficial faculty of pure insight and discrimination. Discrimination, after all, is a function of the mind, which produces a saṁskāra that discriminates between prakṛti and puruṣa. So, by definition, the mind at this point is still engaged and functioning within the contours of prakṛti and therefore actively engaging awareness to this extent.
On another note, Bhoja Rāja understands discriminatory saṁskāras to take the form of the famous aphorism in the Bṛhadāraṇyaka Upaniṣad (IV.5.15): “neti neti,” not this, not this. In other words, pure Brahman, pure consciousness, is not anything prākṛtic—not the body, not the mind, not a table, not a chair, not a mountain, not a universe, not anything external whatsoever. But the act of discriminating in this way is nonetheless still a function of citta, which is itself prākṛtic. The nirodha-saṁskāras block all and every type of such mental functioning. They stand guard, so to speak, over citta and ensure that no thought, not even an insightful discriminatory one of pure wisdom, arises. I have sometimes half jokingly referred to these as the “terminator” saṁskāras.
Hariharānanda understands nirodha as a break in mental activity rather than an actual saṁskāra in its own right, like the spaces in a dotted line, which can be conceived of either as the break in a line or as no line. This interval between the functions of thought, the spaces in the line, can be prolonged by practice and supreme detachment manifesting as absolute disinterest toward anything knowable. This is the kaivalya absolute liberation of III.50. There is now no possibility of rebirth, which under normal circumstances is triggered by the deposit of latent saṁskāras awaiting fruition.
Despite this, Hariharānanda states that some yogīs, wishing to do good to humanity, can enter nirbīja for a specified time and then later reactivate their mind so as to be able to function in the world for the benefit of others. This is something akin to the Bodhisattva of Mahāyāna Buddhism who postpones irrevocably entering nirvāṇa out of compassion for all other embodied beings left suffering in saṁsara. To do this, it would seem that, prior to entering the state of nirbīja–samādhi, such a yogī would have to intentionally deposit a saṁskāra in his or her citta to activate later as a thought that will pull the awareness of the yogī away from total absorption in the self and back into external consciousness mediated by the citta—a type of saṁskāric alarm clock arousing the yogī from samādhi.
Vyāsa continues that when one fully enters into nirbīja-samādhi, the mind, along with all the beneficial saṁskāras that were produced during sabīja–samādhi, dissolves into its primary matrix, the undifferentiated prakṛti. The nirodha–saṁskāras that allow this, Vācaspati Miśra notes, do not provide the mind with a raison d’ětre—they do not perpetuate the mind’s very reason to exist, as even the sabīja–saṁskāras do by providing discriminating wisdom—and so the mind no longer has any purpose to accomplish whatsoever. Vācaspati Miśra points to II.18, which informs us that the mind exists solely to accomplish either of two functions: to provide material experience of saṁsāra, or to lead the soul to liberation. Now that the latter has been achieved in nirbīja–samādhi, the mind, along with the beneficial truth-bearing wisdom saṁskāras that have brought it to this point, ceases all action. The mind therefore, now unemployed, dissolves back into its matrix, prakṛti, as a clay pot, once its function has been accomplished, is discarded and dissolves back into the earth. Then, as Rāmānanda Sarasvatī puts it, “Where there is no cause, there is no effect.” Saṁsāra ceases.
Now, says Vyāsa, the puruṣa can exist in its own right—free, pure, and completely detached. Actually, says Vijñānabhikṣu, it has always been free: Notions of freedom and bondage in relation to the puruṣa are figurative conventions of scripture. Saṁsāra and all it entails exists in the mind, not in the puruṣa itself. The puruṣa becomes apparently ensnared in saṁsāra by dint of the mind erroneously misidentifying with it, and, because of this identification, puruṣa apparently becomes ensnared with the universe of experiences that the mind presents to it. But now, in nirbīja–samādhi, all vestiges of association with the citta have been discontinued, and the final and ultimate goal of yoga has been attained—puruṣa’s unmediated absorption in its own conscious eternal essential nature. Therefore, says Vyāsa, in this state one refers to the free puruṣa as “the pure (śuddha), the self-contained (kevala), and the liberated (mukta).” Actually, it has been that way all along.