Diamond Sutra Explanation. Why do all sages and saints who have realized the unconditioned still have differences?

The sages and worthies include the śrāvaka arhats from the first fruit to the fourth fruit, the pratyekabuddhas who have realized the various grades of the dharma of dependent origination, and the bodhisattvas from the seventh abode of seeing the mind up to wondrous enlightenment (samyak-saṃbodhi). Śrāvakas of the first and second fruits are worthies; those of the third and fourth fruits, along with pratyekabuddhas, are sages. Bodhisattvas before the first bhūmi are worthies, and from the first bhūmi onward they are all sages. What they realize is all unconditioned dharma (asaṃskṛta-dharma), yet the content and levels of these unconditioned dharmas differ greatly. A person of the first fruit realizes the emptiness and selflessness of the five aggregates, eradicates the three fetters, and from then on will not enter the three evil destinies, having no further action with respect to the paths of the three evil destinies — this is the initial stage of the unconditionedness of the five aggregates.

A person of the second fruit, having realized the emptiness of self with regard to persons, has fewer mental activities, diminished afflictions, a somewhat purified mind, and is somewhat unconditioned. A person of the third fruit further realizes the falsity of the five aggregates, the meditative concentration states of the form realm manifest, and attaining the first dhyāna, extinguishes greed and craving, eradicates anger and resentment, eradicates afflictions so the mind is pure, and no longer creates evil karma; the seven consciousnesses begin to be truly unconditioned. A person of the fourth fruit is further unconditioned: he extinguishes the conceit of self, eradicates craving for the form realm and the formless realm, completely eradicates afflictions, attains liberation through wisdom, is unconditioned with respect to the three realms, and can use the wisdom of liberation to transcend the three realms. An arhat liberated through concentration can enter the fourth dhyāna, where breath and pulse both cease, realizing the unconditionedness of immovability; entering the concentration of no perception, he realizes the cessation of the aggregate of consciousness, and the mind attains unconditionedness. An arhat liberated in both ways can enter the cessation of perception and feeling (nirodha-samāpatti) anytime and anywhere, extinguishing the two mental factors of feeling and perception of the manas, realizing the unconditionedness of the cessation of perception and feeling, and can at any time attain nirvāṇa and transcend the three realms. Because śrāvakas realize the selflessness of the five aggregates, their mental activities become increasingly unconditioned and increasingly pure, yet the unconditionedness among them differs greatly.

Pratyekabuddhas include the solitary realizers (pratyekabuddhas who awaken alone) and the conditional realizers. Solitary realizers, due to the roots of goodness cultivated life after life, at a time when there is no Buddha and no dharma abiding in the world, upon seeing a single phenomenon of arising and ceasing in the world, are stirred into deep contemplation. They go alone to a quiet place to cultivate the path, investigating the source of these phenomena of arising and ceasing, probing the dharma of the twelve links of dependent origination and the dharma of the ten links, discovering that the root of sentient beings' birth-and-death saṃsāra is ignorance, and that the source is the eighth consciousness, thereby attaining the fruit of pratyekabuddhahood. Conditional realizers, however, cultivate following the Buddha, and by hearing the Buddha preach the dharma, awaken to the dharma of the twelve links and the ten links of dependent origination and attain the fruit. Their wisdom of unconditioned dharma is deeper than that of the śrāvaka arhats, and the fruit-stage, wisdom, and supernatural powers of pratyekabuddhahood also differ in shallow and deep levels — that is, the degree of unconditionedness of their mental activities differs.

Bodhisattvas see the mind and realize the eighth consciousness, realizing the unconditionedness of suchness (tathatā), while also realizing the emptiness of self with regard to persons, knowing that the eighth consciousness has never arisen nor ceased since beginningless kalpas, and that within the worldly dharmas of the three realms it also gives rise to no mental activities — unconditioned and selfless; the five aggregates are produced by the eighth consciousness, and their essence is empty. In subsequent cultivation, the mind gradually turns pure. Cultivating to the tenth abode, one realizes the contemplation that the five aggregates are like illusions and all dharmas are like illusions. At the ten practices, one realizes the contemplation of miragelike appearances — all dharmas are as insubstantial as a mirage. At the ten dedications, one realizes the contemplation of dreamlikeness: the activities of the five-aggregate bodies life after life are like being in a dream, and the cultivation and practice of the bodhisattva path life after life are also like being in a dream. Bodhisattvas at the first bhūmi realize that the myriad dharmas are as unreal as reflections in a mirror, up through the tenth bhūmi, the stage of anticipation, and wondrous enlightenment, where the realization of unconditioned dharma grows ever greater, wisdom ever deeper, and the powers of supernatural powers and the path ever vaster. As for the ultimate unconditionedness of the buddha stage, it goes without saying — it surpasses all śrāvakas, pratyekabuddhas, and bodhisattvas.

From the above content, because cultivators cultivate different dharmas, the unconditioned dharmas they realize differ; the degree and essence of their unconditionedness differ, their mental activities and mental capacities differ, their merit differs, their progress on the path differs, their states of supernatural powers and meditative concentration (samādhi) differ, and their wisdom differs even more. If one does not stop cultivating and cultivates all the way to the buddha stage, upon reaching the endpoint everything is perfect and complete; the supernatural powers, wisdom, and merit of all are without difference — it can be said that all buddhas realize the same path.