The Ultimate Truth and the Conventional Truth

The mundane refers to the three realms of the world, which encompass the five aggregates and eighteen dhatus, as well as all the material universe. Mundane dharmas are the laws of existence within the five-aggregate world and the operational principles of the material universe. All speech, reasoning, knowledge, opinions, and disputes revolve entirely around this world of the five aggregates and eighteen dhatus. Without the five aggregates, no laws whatsoever would arise. Yet the five aggregates, eighteen dhatus, the three realms of the world, and all dharmas are perpetually subject to birth, cessation, and change.

Truth (satya) refers to ultimate reality. Mundane truth (samvṛti-satya) is the truth concerning the suffering, its origin, cessation, and the path within the five-aggregate world—the truth of suffering, emptiness, impermanence, and non-self within the five-aggregate world. For regardless of era or historical context, the Four Noble Truths of suffering, its origin, cessation, and the path remain eternally unchanging; hence, they are called "truth."

Ultimate truth (paramārtha-satya) is the most genuine principle—the supreme truth, the unsurpassed and incomparable reality transcending both the mundane and supramundane. This points to the true reality of the Tathāgatagarbha, the mind of true suchness—the truth and principles governing the functioning of the Tathāgatagarbha, the mind of true reality. Ultimate truth and mundane truth are often interwoven, functioning together. Only through their integration do all the laws and operational principles of the five-aggregate world arise, does the existence of the three realms come into being, and does mundane truth manifest.

Since truth represents ultimate reality—the genuine principle of all dharmas—embodying great wisdom, the mundane speech of ordinary worldly people cannot constitute truth, nor possess authenticity. It is invariably replete with wrong views and ignorance, neither constituting truth nor qualifying as mundane truth. Only the Four Noble Truths taught by the Buddha are mundane truth, for the Four Noble Truths expound the reality of suffering, its origin, cessation, and the path within the five-aggregate world. They possess authenticity, and through practicing according to them, one can attain liberation and transcend the cycle of birth and death. What ordinary worldly people say cannot be mundane truth. If what worldly people say were mundane truth, then all worldly people would be liberated great sages, and there would be no need for the Buddha to arduously come to this Saha world of five impurities to expound the truth of mundane truth.

Since ultimate truth concerns the reality of the true suchness dharma, then no matter how sentient beings approach matters from the perspective of the Buddha Dharma, it can never be ultimate truth. It remains merely the perceptions and views of the individual’s deluded conscious mind, often laden with numerous wrong views and errors. Even if devoid of wrong views and entirely composed of correct reasoning, it still is not the ultimate truth of the Tathāgatagarbha. Ultimate truth refers to the true reality of the principle-essence—the Tathāgatagarbha, true suchness, which is neither born nor extinguished, neither defiled nor pure, neither increasing nor decreasing, neither permanent nor annihilated. No speech, discourse, knowledge, or viewpoint represents the true suchness itself; therefore, none constitute ultimate truth. They are merely false perceptions and deluded cognitions.