Is it direct-perception wisdom when mind consciousness alone knows dharmas through deliberation, analysis, understanding, and inference?

The conclusions reached through the mind consciousness's thinking and reasoning are not realized through practice, not personally attained; they lack genuine, usable evidence to support them, and the inner doubts have not been severed. When at some point one encounters facts that contradict them, one will regret and overturn one's former conclusions. Moreover, the deep doubts within the manas cannot be discovered at all when the mind consciousness lacks wisdom; therefore, the mind consciousness's inferences cannot sever doubt and make the manas give rise to faith—then there is no practical use and no benefit to be received.

Even if the result of the reasoning is completely correct, one hundred percent correct, it is still non-valid cognition. Why? For example, suppose you reason that I must have stolen your things, and in fact I really did steal them; but since you did not see it with your own eyes or catch me with your own hands, your reasoning is useless—the court will not convict and sentence me based on your reasoning or anyone's reasoning. Even if I myself admit that I stole, but cannot produce strong evidence proving that I stole, the court still cannot pass sentence. Some people, in order to exonerate those with whom they have karmic affinity from their offenses, are willing to take the punishment in their place; but without genuine, convincing evidence, even if they go to court to confess, admitting that the offense was personally committed by themselves and has nothing to do with others, the court still cannot convict and sentence based on one-sided words.

In the Buddha's Dharma, when there is no meditative concentration (samādhi), even if one infers the existence of the eighth consciousness amid the activities of the five aggregates and eighteen realms, and imagines that the eighth consciousness has a certain function, certain functions, because there is no personal realization and attainment, this kind of reasoning has no merit or benefit to be received, will not change anything; the view of self (satkāya-dṛṣṭi) still remains as before, the three fetters still bind oneself as before, and one cannot escape the retribution of the three evil destinies at the end of life. You may be allowed to have inferred the eighth consciousness correctly, allowed to imagine fifty or sixty percent, sixty or seventy percent, seventy or eighty percent of it, but still no great wisdom will arise, there will still be no meditative absorption (samādhi) state, still no merit or benefit to be received, and one is still an ordinary person; one will never, because of such imagination and reasoning, sever ignorance and afflictions.

The methods and means of practice used by the patriarchs through the ages and generations, the paths they walked, are absolutely correct, accord with direct perception, and their attainments are genuine and credible; they have had an enormous positive influence and driving force on Buddhism. The patriarchs' teachings all reveal the truth of practice and realization—all are true knowledge born of practice. Later generations of sentient beings, due to meager merit (alpa-puṇya) and deep obstructions, are unable to devote body and mind to diligent practice as the patriarchs did; mostly it is the mentality of opportunism and cutting corners at work, and everyone wants to take shortcuts. Practice means to abandon the self, regardless of all cost—where is there any shortcut to take? One step less on the path means one portion less of merit gained, one portion less of bodily and mental experience, one portion more of loss suffered; in fact this is a practice of first deceiving oneself and then deceiving others. If there were a shortcut to take, would the Buddha not have told us and guided us? Sentient beings suffer so much—would the Buddha not wish for sentient beings to attain the Buddha-way as quickly as possible and take fewer detours?

Any practice that does not accord with the Buddha's teachings, any practice that violates the Buddha's original intent and harms the interests of sentient beings, will in the end be destroyed and removed from Buddhism—it is only a matter of time, sooner or later.