What is conventional truth? What is ultimate truth?

Conventional truth (saṃvṛti-satya) is the truth of worldly phenomena; ultimate truth (paramārtha-satya) is the supreme truth, the truth that transcends worldly phenomena. Worldly phenomena are the world of the five aggregates (pañcaskandha)—what does the truth refer to? It refers to conditioned dharmas marked by suffering, emptiness, impermanence, and non-self. What dharma transcends the worldly dharma of the five aggregates? The Mahāyāna tathāgatagarbha dharma transcends the worldly dharma of the five aggregates. The Small Vehicle dharma still belongs to conventional truth; although it is supreme within the category of worldly phenomena, it is not supreme enough—only the Mahāyāna tathāgatagarbha dharma is the most supreme, and it is called ultimate truth. As for the Small Vehicle's conventional truth, although it can enter nirvāṇa without remainder (anupadhiśeṣa-nirvāṇa) and attain liberation, it has not transcended the worldly dharma of the five aggregates; only the tathāgatagarbha dharma transcends worldly phenomena. The suffering, emptiness, impermanence, and non-self of conventional truth—the truth it reveals falls within the category of the worldly realm of phenomena, whereas the transcendental truth, the Mahāyāna tathāgatagarbha dharma, goes beyond the worldly realm of phenomena. The two truths describe different levels and depths.

So what is the difference between ultimate truth (shengyidi) and noble truth (shengyidi)? Ultimate truth is the truth of the first meaning (paramārtha). It cannot be spoken of; it is inconceivable. Noble truth, as the name suggests, is the authoritative teaching spoken by the Buddha. The former is the moon; the latter is the finger—the meanings are somewhat different. "Sheng" (胜) means supreme, surpassing, victorious, and superior; this is the truth manifested in comparison with the mundane world. "Sheng" (圣), in contrast to the ordinary, represents the noble ones; it means being detached from the mundane, surpassing the mundane, and also means purity. From the perspective of the connotations of these two characters, they are the same: both carry the meaning of transcending the world of the five aggregates, and in substantive meaning they are also the same; there is only a slight difference in fine points—a difference in the aspect each emphasizes. The character 胜 emphasizes supremacy and transcendence, while 圣 emphasizes purity and extraordinariness, and the inner quality of holiness. Thus ultimate truth denotes the most supreme dharma, while noble truth denotes the dharma spoken by Buddhas, bodhisattvas, and various noble ones; the dharma spoken by noble ones all points toward ultimate truth.

If one realizes both conventional truth and ultimate truth and fully penetrates them, the two truths become perfectly harmonized, and one's mind becomes empty, signless, and wishless—nothing to do, nothing to make, nothing to seek. A noble one does not even act as a noble one—how could he act as an ordinary person? Not acting as either noble or ordinary, the mind is pure—how could there be any precept-marks to keep or to violate? How could one delight in worldly fame, gain, and offerings, or in wealth, sex, fame, food, and sleep? If one does not even do what is wholesome, how could one do the slightest evil? The reason a person grasps at the marks of worldly phenomena is that he has not penetrated the two truths and lacks the wisdom of the two truths; with marks still unextinguished in his mind, he will have things to do and things to grasp, and thus inevitably karma will entangle him. Speaking of the perfect harmony of the two truths—have arhats harmonized the two truths? Have pratyekabuddhas harmonized the two truths? Have bodhisattvas harmonized the two truths? Only Buddhas and bodhisattvas can perfectly harmonize the two truths. Arhats and pratyekabuddhas can only harmonize conventional truth; only after emerging from nirvāṇa without remainder, generating the great bodhi mind, and realizing the tathāgatagarbha do they gain the ability to perfectly harmonize the two truths.

As for the five dharmas of Yogācāra—marks (lakṣaṇa), names (nāma), discrimination (vikalpa), correct knowledge (samyag-jñāna), and suchness (tathatā)—which is conventional truth, and which is ultimate truth? Can correct knowledge be apart from marks, names, and discrimination? What kind of wisdom is correct knowledge? How is it obtained? On what dharma is it obtained?