What does unconditioned dharma refer to?

Unconditioned dharmas refer to two things: one is the inherent unconditioned nature of the true mind, and the other is the unconditioned mental nature that the deluded mind of the seven consciousnesses acquires through cultivation. The unconditioned is without arising and ceasing, while the conditioned has arising and ceasing. The eighth consciousness possesses both conditioned and unconditioned natures.

The unconditioned nature of the eighth consciousness means that the nature of the self-mind is non-active: toward all dharmas it is without mind, without any mental activity that actively seeks to create anything, and it does not exercise control over any dharma. Although the eighth consciousness does engage in creation and has mental activity when it gives rise to the myriad dharmas, its mental nature remains unconditioned—it has no mind that actively creates, does not know what it is creating, knows nothing whatsoever about the dharmas of sense objects, and does not wish to know them, yet it can give rise to all dharmas in accordance with conditions. If the eighth consciousness were not an unconditioned dharma, then there would be no unconditioned dharma at all in either the mundane or supramundane world. No matter how unconditioned the seven consciousnesses may become, they can never be as unconditioned as the eighth consciousness—even the seven consciousnesses at the buddha stage are like this.

How is the eighth consciousness unconditioned? Although it creates countless worldly dharmas, its mind remains empty, without mind, without aspiration, without arising or ceasing, without any nature of exercising control, and without any nature of self. The eighth consciousness is without a nature of self; what is without self is unconditioned—it does not act for a self, not for any purpose, and has no self-interest. If a mind without self still belonged to conditioned dharmas, that would be a serious contradiction.

If the eighth consciousness were purely a conditioned dharma, it would necessarily be subject to arising and ceasing. How is the eighth consciousness conditioned? Creating worldly dharmas is precisely what makes it conditioned. If the eighth consciousness were purely conditioned, how could the seven consciousnesses draw close to it, learn from it, and transform their own mental nature? How could the seven consciousnesses face all states of experience immovable in suchness (tathatā-acalita)? How could the seven consciousnesses attain the unconditioned and accomplish the buddha path? What would the seven consciousnesses learn from the eighth consciousness? If the eighth consciousness were purely a conditioned dharma, then there would be no need for us to investigate Chan (canchan) to realize the eighth consciousness, and after enlightenment we would be unable to undertake the transformation of the basis (āśraya-parāvṛtti) toward its pure and unconditioned nature; the seven consciousnesses would never be able to transform their mental nature, and thus neither the enlightened nor the unenlightened could ever attain buddhahood.