He is now me, I am now not him.

Monk Dongshan crossed a river, saw his reflection in the water, and suddenly awakened, composing the verse: 渠今正是我，我今不是渠。

Question: Who does "渠" (that one) refer to? Who does "我" (I) refer to? What is the relationship between the two? Monk Dongshan pointed at the reflection in the river and said: You right now are precisely me, yet I am not you. The reflection is the five aggregates (pañca-skandha) manifested by the eighth consciousness; it comes from the eighth consciousness and is the shadow of the eighth consciousness. Speaking from the ultimate meaning of Consciousness-only, the five aggregates can be said to be the eighth consciousness, but the eighth consciousness is certainly not the five aggregates. These dharmas can be understood by thinking them over and pondering them—nothing extraordinary. You may call it understanding-based awakening, or you may say there was no understanding-based awakening; but to call it realization requires a thorough examination from the inside out and from top to bottom. Examine what? Examine whether his mind has changed and whether wisdom has arisen. Because upon realizing that the five aggregates are merely a shadow, one is surely greatly astonished, with waves surging in the mind—everything one previously believed and grasped (upādāna) was wrong. What state is the mind in at that moment? For someone who has not realized it many times, for someone without the power of mind-reading, how could one know whether this person has realized it or merely understood it? Ordinary people absolutely cannot detect it—one could say one hundred percent cannot detect it—they can only parrot what others say. Realization is great wisdom; being able to accurately examine whether someone has realized it is an even greater wisdom, far, far greater than the wisdom of realization itself. 

With realization, one can observe directly and in the present the relatively simple and coarse operation of the eighth consciousness, which understanding-based awakening cannot compare to. With understanding-based awakening, there is only a hazy shadow in the mind, vague and indescribable, not knowing exactly how the eighth consciousness operates or how the five aggregates are born. No matter how much theory he expounds, there is not a single bit of accurate, detailed content—just like floating on the surface of the water, unable to enter the water, not knowing the situation beneath it. Some people claim they are enlightened great bodhisattvas who have realized the eighth consciousness, the tathāgatagarbha; yet for many years this "great bodhisattva" has never expounded even slightly detailed aspects of how the eighth consciousness, the tathāgatagarbha, operates—only broad, vague, sweeping theoretical frameworks. Those theories could roughly be figured out just by reading the sutras and the treatises of the bodhisattvas—nothing remarkable. As for the Chan koans, by watching the masters gesturing and posturing when giving dharma talks in the hall and receiving students, one can roughly glean something; imitating their manner, quite a few people can do it too—nothing remarkable. Even the little disciple of the One-Finger Zen master could also use the one finger, outwardly just like his master, yet it was not Chan. Modern people's capacity for fakery is unparalleled—from the secular world to Buddhism, it is all the same—caused by heavy karma, heavy afflictions, and a heavy sense of self. 

Those who imitate the gestures and posturing of the Chan patriarchs may be said to have understanding-based awakening, or may be said not even to touch the edge of understanding-based awakening. Taking the function of the mind consciousness to be the function of the eighth consciousness—that is a non-Buddhist path; taking the combined function of the eight consciousnesses to be the function of the eighth consciousness alone—that is inference and speculation. Laypeople absolutely cannot see through it and are often left dumbfounded and intimidated. This trick can deceive even the heavens and slip past the sea, because sentient beings' insight is far too shallow—they are truly foolish and easily intimidated. Therefore, when you are deceived, you should turn back and examine yourself: why were you able to be deceived? Why do other people have bright eyes and clear minds and are not deceived? When you walk down the street and accidentally bump into someone, and that person glares at you and says: "I am a sage who has attained the fruit—how dare you bump into me?" Upon hearing this, you just laugh heartily, say "sorry," and that is the end of it—no need to be surprised, and no need to say anything more.