An Overview of the Diamond Prajñāpāramitā Sūtra

The Diamond Sutra is the essence of the six hundred fascicles of the Great Prajñāpāramitā Sūtra; the entire text expounds the true nature of the indestructible vajra mind. The vajra (diamond) is the hardest treasure in the world—no one, with any amount of force, can destroy it; on the contrary, it can destroy everything. Likewise, the tathāgatagarbha, like the vajra, is indestructible, yet it can extinguish all dharmas. How does it extinguish them? Because the indestructible vajra mind exists, even though all dharmas exist, they are still empty; and if the tathāgatagarbha withdraws the seven great seeds, all dharmas vanish immediately, and even the appearance of illusory existence is extinguished. Nothing could be more fitting than the World-Honored One using the nature of the vajra as a metaphor for the true suchness mind-substance of every sentient being. The unborn-and-undying nature of the true suchness mind-substance far surpasses the durability of the vajra. The vajra is a worldly material form (rūpa-dharma); when the world is destroyed, it too ceases to exist. But the vajra mind, the tathāgatagarbha, is not destroyed along with the world, because the vajra mind tathāgatagarbha does not fear water—water cannot drown it; it does not fear fire—fire cannot burn it; it does not fear wind—wind cannot break it. The three calamities can do nothing to Him, and even the most modern weapons can do nothing to Him. The vajra minds of all sentient beings throughout the worlds of the ten directions are like this: unborn and undying, never subject to destruction.

It is because the vajra mind exists that sentient beings' five-aggregate physical bodies are born and perish life after life. Unless sentient beings eliminate the self-view (ātma-dṛṣṭi) and extinguish self-grasping, severing all craving and attachment to the three realms (the desire realm, the form realm, and the formless realm), and at the end of life enter nirvāṇa without remainder (anupadhiśeṣa-nirvāṇa), extinguishing the five aggregates and the eighteen realms, the five aggregates of future lives will never again arise. But the vajra mind-substance still does not perish; it exists independently, by itself, without relying on external conditions. For this reason the vajra mind is called the self-sufficient mind: it can exist alone without depending on other conditions, and it does not need anyone to give birth to it or manifest it. However, although bodhisattvas attain the fruit of liberation, they do not enter the fixed stage; before the seventh bhūmi, bodhisattvas do not realize the fourth fruit, and so they will not enter nirvāṇa without remainder. Bodhisattvas must still, life after life, make use of the five-aggregate physical body to cultivate and study the Buddha Way, benefiting themselves and benefiting others, until they attain buddhahood, never ceasing their conduct of benefiting others.

Why can sentient beings who study and practice the Buddha's teachings attain buddhahood? It is because of the cooperation of this vajra mind, which can store the seeds of wholesome karma; when the seeds are perfectly matured, one becomes a Buddha. Even bacteria, too small to be seen by the naked eye, possess this vajra mind. This mind is the true substance for attaining buddhahood, the Dharmakāya that gives birth to all dharmas. One sentient being has one vajra mind, and one vajra mind can accomplish one Buddha. Since there are immeasurable, boundless sentient beings in the worlds of the ten directions, there will in the future be immeasurable, boundless World-Honored Ones (Buddhas). A physical body held and sustained by the vajra mind is called a sentient being: it has the life activities of the five aggregates and has bodily, verbal, and mental actions. An object without a vajra mind operating in it personally, without seeds of consciousness being produced, is called an insentient thing. Mountains, rivers, and the great earth, flowers, grass, and trees have no five aggregates (form, feeling, perception, formations, consciousness), nor any bodily, verbal, and mental actions; they are not sentient beings, and therefore cannot become Buddhas.

The vajra mind is different from things like the "soul" spoken of by non-Buddhists. Non-Buddhists also believe that sentient beings all have a mind-substance that never perishes and can go on to future lives. But the mind-substance they refer to is, in terms of its nature, the mind consciousness, which is subject to arising, ceasing, and change; it is suffering, empty, impermanent, and non-self, with a strong capacity for discriminating wholesome from unwholesome; therefore it is not the ever-enduring vajra mind. The mind consciousness has times when it ceases: it ceases in sleep, ceases in a coma, ceases in the concentration of no-perception, ceases in the cessation of perception and feeling, and ceases even more at death. Since it can cease, it is not a true dharma and cannot go on to future lives.

The nature of the vajra mind is utterly different from that of the mind consciousness: it never perishes or is lost, not even for a single instant has it ever disappeared; otherwise sentient beings would die on the spot. It does not discriminate the wholesome and unwholesome, the true and false, you, me, him, or it; it always accords with the mental activities of sentient beings, cooperates with the seven consciousnesses, and makes great generosity (dāna) to sentient beings without seeking any return, working throughout the future without abiding in any dharma, selfless and without self. This is the Buddha mind. It has countless names; the definitive Buddhist sūtras describe Him everywhere, saying He is the mind of intrinsically pure self-nature, the tathāgatagarbha, the ālayavijñāna, the vipākavijñāna (retributive consciousness), the undefiled consciousness (amala-vijñāna), the eighth consciousness, true suchness, suchness of reality, the ultimate reality, the original basis, the boundless, the one true dharma realm, and so on—too many to enumerate.

He pervades all the stages (the nine stages of the three realms), pervades all places (the twelve bases/āyatanas), pervades all realms (the eighteen realms), pervades all times, and also pervades all dharmas. On whichever dharma He does not operate, that dharma does not exist. All the worlds of the ten directions are manifested by Him; not a single dharma is not contained within His mind-substance. He is the Tathāgata Buddha; the ten thousand dharmas have never escaped the palm of the Tathāgata Buddha's hand. The Buddha said in the Śūraṅgama Sūtra: 虚空在汝心内如片云点泰清里 — so how vast this mind must be! But even "vast" is still "small"; He is neither great nor small.

Realizing where this mind appears, where it exists, and how it operates is the enlightenment of the Chan school. If one merely understands the principle by following the words of the text, without knowing exactly where He is, unable to observe how He operates and how He gives rise to the five aggregates, then it does not count as enlightenment; it is merely a similar understanding at the level of the mind consciousness. How should one, in studying and practicing Buddhism, attain enlightenment to the vajra mind and come to know the function of this mind? One must use the method of investigating Chan. Each of the seventeen hundred Chan koans of the Chan school is a finger pointing to Him. From the time of the Buddha in the world down to the recorded koans of the eminent masters of the Yuan, Ming, and Qing dynasties, all are fingers pointing at the moon; not a single phrase departs from this mind.