To realize the mind and see one’s true nature is to realize that the mind is fundamentally nonexistent and to see that intrinsic nature is inherently present.

As stated above, mind and intrinsic nature are like phenomenal function and principle-essence. Although phenomenal function has forms that can be seen with the eyes, it only seems to exist and is in fact without real existence, because dependent arising is empty of intrinsic nature. Although principle-essence has no form that can be seen, it only seems not to exist and is in fact truly present, because emptiness of intrinsic nature gives rise to dependent arising. The two support and complete each other: apart from essence there are no forms, and apart from forms there is no essence. Hence it is said: neither empty nor existent; both empty and existent; emptiness itself is existence. Not only must we not cling to any phenomenal appearances and fall to one side; we must also see through these illusorily arisen appearances and clearly behold the true essence of intrinsic nature.

The Śūraṅgama Sūtra says: “The nature of form is true emptiness; the nature of emptiness is true form.” The essence of intrinsic nature is true emptiness, without any form; only true emptiness without form is the essence of intrinsic nature. All forms are delusive forms. Delusive forms have no substance; like flowers in empty space and the moon reflected in water, they cannot be grasped. They are nothing but deluded thoughts.

Thus, the Heart Sūtra says that all is nonexistent: there are neither the eyes, ears, nose, tongue, body, mind, nor forms, sounds, smells, tastes, tactile objects, and dharmas of worldly dharmas; neither are there the Four Noble Truths and the twelve links of dependent origination of the śrāvakas and pratyekabuddhas; still less are there the wisdom and attainment of bodhisattvas. It is precisely where nothing whatsoever can be attained that anuttara-samyak-saṃbodhi is attained. This reveals that, where the mind is clearly seen to be fundamentally nonexistent, we thoroughly behold the inherently present essence of intrinsic nature.

In the Chan school, this is called the school of extinguishing all traces and leaving nothing to rely upon. When Layman Pang asked Mazu, “Who is the person who does not keep company with the myriad things?” the Patriarch replied, “When you have swallowed all the water of the West River in one gulp, I will tell you!” When thoughts are extinguished and emptiness and existence both vanish, the wondrous essence of true emptiness naturally appears. Similarly, the modern Chan Master Chuquan went to study with Dharma Patriarch Chishan.

One day, the Patriarch asked, “The Lotus Sūtra speaks of opening, revealing, awakening to, and entering the Buddha’s knowledge and vision. The patriarchs of every generation have each given their own explanations, but those are the explanations of the individual patriarchs and have nothing to do with you. Now I want you to speak from your own breast: how would you open, reveal, awaken to, and enter the Buddha’s knowledge and vision?” The master had no reply. The Patriarch sighed, “To investigate Chan in this way is merely to waste one’s time. What benefit can there be?” He punished him by ordering him to investigate Chan while kneeling.

After investigating for three incense periods in succession, he heard the cantor strike the board marking the end of the sitting and suddenly awakened. The Patriarch examined him, asking, “How does one open the Buddha’s knowledge and vision?” He answered: “Open forth what is inherently present—that is, the principle-essence of intrinsic nature that is inherently present.”

He then asked, “How does one reveal it?” He answered: “Reveal what is fundamentally nonexistent—that is, all the phenomenal functions and appearances of mind are unobtainable; through these unobtainable functions of mind, reveal the true essence of intrinsic nature.” He asked again, “How does one awaken?” He answered: “Awaken to there being neither existence nor nonexistence—thus eradicating all traces of delusion and awakening.” He further asked, “How does one enter?” He answered: “Enter and emerge without obstruction—thus gaining great benefit and being free and unimpeded in speech and silence, activity and stillness.”