Can Being Certain Mean There Is Truly No Doubt?

It is said that scientists used instruments to determine that the Earth is oval-shaped, and almost everyone believed it—moreover, it seems to be the kind of belief that is held with complete certainty, as if such belief had already taken deep root and become unalterable. If someone does not believe it, others will even go and debate with them, even mocking and ridiculing them. But this is still not true belief and true non-doubt. Belief has many levels; some people even firmly believe without any doubt, utterly convinced, without the slightest hesitation. But if one has not personally verified it, all such belief belongs to blind faith and superstitious faith, not verified faith born of realization. Therefore doubt still exists—it is merely deep and hidden, not easy to observe. 

Knowing that the Earth is oval-shaped is merely hearsay, not something seen with one's own eyes; it is knowledge the mind consciousness has acquired through hearsay. Since the manas has not personally seen it, doubt has not been eliminated. Moreover, even what many people see with their own eyes may not necessarily be true and real—cases of seeing wrongly are extremely numerous; what the eyes see is not necessarily real. Therefore the manas's doubt cannot be eliminated. Once some other condition arises and it is said that the Earth is actually not oval-shaped but rhombus-shaped or triangular, quite a few people's former belief will waver and turn into disbelief. Why can faith change? Because there has been no personal realization. No matter to what degree the mind consciousness is convinced, it is unreliable; once conditions change, the mind consciousness's doubt will appear. Why? Because the manas never believed in the first place and has not eliminated doubt. Once conditions change, without the support of the manas's personal realization, the mind consciousness becomes fickle and loses its backbone—or rather, the mind consciousness's backbone has always been the manas, and at critical moments it invariably turns along with the manas. Only by truly seeing the Earth, by genuinely witnessing the Earth's shape from an overall and macroscopic perspective, can the manas eliminate doubt and give rise to faith. In the future, even if conditions change, the manas will still firmly believe without doubt, and then the mind consciousness will follow the manas in firm belief without doubt; even if the mind consciousness has doubt, it will not take effect, and it will still trust the manas. 

Some people say that as long as you yourself are convinced that you have eliminated the self-view (ātma-dṛṣṭi) and have no doubt, you have attained the first fruit. How childish and laughable such a claim is! Is the worldling's firm conviction without doubt reliable? If it were reliable, why are sentient beings so fickle, changing their minds at the slightest stir and ceasing to believe? If the worldling's conviction and non-doubt were reliable, why did the Buddha say, "Beware of trusting your own mind, for your mind is not to be trusted," and that only upon attaining arhatship may one trust one's own mind?

Throughout history, those recorded as having confirmed for others the elimination of self-view and the attainment of the fruits are, first, the Buddha himself during the Buddha's lifetime, and second, the Fourth Patriarch Prajñāgupta after the Buddha's parinirvāṇa. As for the Buddha, that goes without saying: with immeasurable wisdom, unlimited supernatural powers, and omniscience—his knowledge of others' minds and recollection of past lives—he could know and see exactly the thoughts of all sentient beings; whether his disciples had attained the fruits, the Buddha could know immediately without even meeting them. As for the Fourth Patriarch Prajñāgupta, he had not only attained arhatship but also possessed great supernatural powers; he had even personally subdued Māra Pāpīyas's various provocations, restoring purity to Buddhism. According to the Fourth Patriarch's realization of liberation and his recollection of past lives and knowledge of others' minds, he could of course also know immediately whether his disciples had attained the fruits, without error. Others who lack realization, whose wisdom and realization are insufficient, and who have no supernatural powers or spiritual strength, are probably unable to accurately observe another person's mental state, and therefore cannot confirm for others whether they have attained the fruits. Those with extremely profound wisdom, who have attained the fruits countless times over successive lifetimes and are rich in experience, can accurately confirm the timing and circumstances of fruit-attainment for others even without supernatural powers; apart from such people, no one else has the ability or qualification to confirm attainment for others. How much less can worldlings confirm themselves—lacking experience, misjudgment is simply unavoidable, and the consequences are unimaginable. 

Practicing the Buddhadharma should be even more pragmatic and rigorous than worldly affairs; one must not treat the Buddhadharma as child's play, thinking it is very simple. Nothing is more difficult than the Buddhadharma, because sentient beings have been engaged in worldly affairs for beginningless kalpas and are far too unfamiliar and unpracticed with the Buddhadharma; added to this are layer upon layer of karmic obstructions, and the obstacles are often far greater than we imagine. Therefore, studying the Buddha's teachings and cultivating practice in a down-to-earth manner is our proper duty, so as not to further increase karmic obstructions and afflictions and sink deeper into the abyss of birth and death.