Answer: The six entrances are the eye entrance, ear entrance, nose entrance, tongue entrance, body entrance, and mind entrance, including the external six entrances: form, sound, smell, taste, touch, and dharmas; and including the internal six entrances: the eye faculty, ear faculty, nose faculty, and body faculty within the supreme faculties (rūpa-prasāda), as well as the manas. These internal and external six entrances are all worldly dharmas. The first seven consciousnesses all correspond to worldly dharmas, being able to discern and discriminate worldly dharmas, and to comprehend the worldly meanings of these worldly dharmas—this comprehension is the meaning of "engaging."
The eighth consciousness, however, cannot comprehend the worldly meanings of these worldly dharmas; it does not engage with these worldly dharmas. Otherwise, the eighth consciousness would, like the seven consciousnesses, develop attachment and grasping toward worldly dharmas, afflictions would arise, and it would correspond to birth and death. This is why it is said that the eighth consciousness does not engage with the entrances (诸入不会).
However, the eighth consciousness has no beginningless ignorance (avidyā); there is no dharma it does not know and no dharma it does not understand. Moreover, it can condition all dharmas, mentally engaging (manaskāra), contacting (sparśa), feeling (vedanā), perceiving (saṃjñā), and deliberating (manana) upon all dharmas, and thus it can truly discern all dharmas, know all dharmas, discriminate 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 He constantly, at every moment and instant, uphold and sustain the six sense faculties and six sense objects, and transform them? The eighth consciousness also engages in feeling, perception, and deliberation (vedanā, saṃjñā, manana) regarding the six sense faculties and sense objects, with choices and subsequent karmic formations. He must therefore know and understand the six sense faculties and sense objects, and that is precisely why He necessarily knows how to act and form.
It is only that the eighth consciousness does not know the worldly dharma-marks of the six sense faculties and sense objects, and does not know their worldly content—all of this is content known by the seven consciousnesses. What does the eighth consciousness know, and what does it engage with? Without profound seed-wisdom of Consciousness-Only (唯识种智), one cannot observe the "knowing" and "engaging" of the eighth consciousness; then you would have to ask the eighth consciousness itself. The eighth consciousness has no beginningless 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 karmic formations, and confused karmic retribution, the eighth consciousness is never confused or disordered.
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