The Essence of the Eighth Consciousness Can Only Be Realized Through Self-Inquiry and Self-Awakening.

The eighth consciousness is the mind of ultimate reality (dharmatā-citta), the true substance. When we speak of the eighth consciousness with our mouths, the eighth consciousness becomes a mark in our minds; this mark is not the substance of the eighth consciousness. The substance of the eighth consciousness neither comes into our mouths nor enters our minds. Any mark in the mind, including the operational characteristics of the eighth consciousness, is a conjured appearance—and moreover, it is conjured forth by the eighth consciousness. Talking can never reach the substance, just as cursing can never strike the other person's five aggregates, nor can it strike the other person's mind.

When we discuss the eighth consciousness, we can only present the mark of the eighth consciousness in our minds; we cannot take the substantial mind-substance of the eighth consciousness and show it to others. Even the Buddha could not hold up the substance of the eighth consciousness and present it to the world. Therefore, investigating Chan must be done by oneself—each person must find where their own substance of the eighth consciousness lies. Whatever the five aggregates and the seven consciousnesses can contact and can manifest is not the original appearance of that substance, nor is it the objective realm itself.