Is the Self-Witnessing Portion of the Eight Consciousnesses Able to Continuously Manifest and Operate?

The self-witnessing portion, which refers to introspective power and the power of awareness and perception, does not constantly manifest in the seventh consciousness. This is because when the power of meditative concentration (dhyāna) and the power of wisdom (prajñā) are insufficient, the conscious mind lacks the capacity for self-reflection and self-observation. The eighth consciousness, however, constantly possesses introspective power and the self-witnessing portion because its concentration and wisdom are perpetually present, unchanging, neither increasing nor decreasing, existing without the need for cultivation.

For example, the self-witnessing portion of the sixth consciousness (mano-vijñāna), which involves constant awareness and observation of one's own mind, requires very strong power of concentration and considerable wisdom. The method of contemplative practice (vipassanā) taught by the Buddha in the Mahasatipatthana Sutta is precisely this method of being aware of one's own mind. One must know whatever one is doing; with this knowing, the mind attains concentration. Without knowing, the mind becomes scattered. Why did the Buddha teach this? Because the minds of sentient beings are scattered and unable to be aware of their own minds. Being aware of one's own mind is the self-witnessing portion; if one cannot be aware of one's own mind, the self-witnessing portion is absent.

Those who possess introspective power and can be aware of their own minds, on one hand, have a certain degree of wisdom, and on the other hand, possess a certain degree of concentration. This is true regardless of whether one studies Buddhism or not. Therefore, the wisdom of each person differs: some understand themselves, while others do not. Similarly, the other consciousnesses are like this too; the self-witnessing portion cannot always be present and functioning.

The self-witnessing portion is introspective power. It enables observation of what one is doing, what one has already done, and what one intends to do. Within this, it inevitably involves the seeing portion (dṛṣṭi-bhāga) and the appearing portion (nimitta-bhāga), and it cannot be separated from the self-confirming portion (svasaṃvitti-bhāga). The "what" in "doing what" is the appearing portion. The "doing" is the seeing portion. "Doing what" is the self-confirming portion. Knowing "what has been done" is the self-witnessing portion.