Does Human Nature Fully Possess the Ten Dharma Realms?

The tathāgatagarbha is endowed with the natures of the ten dharmadhātus, whereas the manas cannot possibly be endowed with the natures of the ten dharmadhātus. If the manas had Buddha-nature, then one would be a Buddha within a single thought-moment; if that were so, could one extend this single thought to ten, a hundred, a thousand thoughts and thereby be a Buddha for half a day or a whole day? The manas of a Buddha, and the manas of śrāvakas, pratyekabuddhas, and bodhisattvas, cannot possibly possess the unwholesome nature of beings in the three evil destinies, nor does it possess the nature of ordinary beings of the six destinies.

Intrinsic nature is precisely the mental factors (caittas). By observing the mental factors of the manas, one can know a person's intrinsic nature; by observing the mental factors of the tathāgatagarbha, one can even better know the future destination of sentient beings—they will undoubtedly become Buddhas.

The manas of ordinary beings differs greatly from the manas of śrāvakas, pratyekabuddhas, and bodhisattvas, and from the manas of a Buddha. Likewise, the mental factors of the manas and the mental factors of the tathāgatagarbha also have their respective differences; only the mental factors of the Buddha's manas and those of the Buddha's undefiled consciousness (amala-vijñāna) have no difference. If sentient beings were Buddhas—Buddhas in the true sense—then the mental factors of the manas should be identical to the mental factors of the tathāgatagarbha: without any unwholesome mental factors, with the five universal mental factors complete, the five object-specific mental factors complete, and the eleven wholesome mental factors complete.