Not understanding the six sense bases is not the same as not discriminating them.

The Buddha said in the Vimalakīrti Sūtra that the eighth consciousness is the bodhi mind: "The six entrances do not engage with it (诸入不会); that which does not engage is bodhi." Does "not engaging with the six entrances" mean not discriminating the six entrances? Who obtained the Fifth Patriarch's robe and bowl? The one who did not understand the Buddha-dharma obtained it. What does this "not understanding" mean? It means not knowing or comprehending the specific contents of the Buddha-dharma—this refers to the eighth consciousness, the bodhi mind.

The six entrances include the eye entrance, ear entrance, nose entrance, tongue entrance, body entrance, and mind entrance, encompassing the outer six entrances: form, sound, smell, taste, touch, and dharmas, and the inner six entrances: the eye supreme faculty, ear supreme faculty, nose supreme faculty, tongue supreme faculty, body supreme faculty, and the manas. The six consciousnesses, which arise in dependence on the outer six entrances and the inner six entrances, both know and understand the six sense faculties, and also know and understand the six sense objects. But the eighth consciousness, the bodhi mind, neither knows the six sense faculties nor understands what they are, and neither knows the six sense objects nor understands what they are.

Question: Does not knowing and not understanding the six sense faculties and six sense objects mean not discerning and not discriminating them?

The eighth consciousness has no ignorance (avidyā); it can condition all dharmas—attention (manaskāra), contact (sparśa), feeling (vedanā), perception (saṃjñā), and volition (cetanā) with respect to all dharmas—and thereby can truly know all dharmas and understand all dharmas. If the eighth consciousness did not know or understand all dharmas, did not know or understand the six sense faculties and six sense objects, then how could It constantly, every minute and every instant, uphold and sustain the six sense faculties and six sense objects, and transform them? The eighth consciousness also engages in feeling, perception, and volition with respect to the six sense faculties and six sense objects, makes choices, and carries out subsequent actions; It must therefore know and understand the six sense faculties and six sense objects, and so It necessarily knows how to act. It is only that the eighth consciousness does not know the worldly dharma characteristics of the six sense faculties and six sense objects, and does not know their worldly contents—all of these are contents known by the seven consciousnesses. What does the eighth consciousness know? When one does not yet possess the profound wisdom of the seeds of Consciousness-only (唯识种智), one cannot observe the knowing of the eighth consciousness—one would have to ask the eighth consciousness itself. The eighth consciousness has no ignorance; It discriminates all dharmas with perfect clarity, without the slightest error or confusion, unlike the seven consciousnesses, which in many cases discriminate unclearly, resulting in confused choices, confused actions, and confused karmic retribution.