Only with conclusive evidence can the manas be convinced

The seventh consciousness only believes in reality and facts; the five-sense-object states and matters and principles whose evidence is insufficient or unreliable are things the seventh consciousness refuses to believe. Even if the mind consciousness engages in erroneous cognition (non-valid cognition), if the evidence is conclusive and the conclusion drawn fully accords with the facts, the seventh consciousness can also believe it. Only after the seventh consciousness believes can a decision be made; otherwise, the seventh consciousness will temporarily refrain from making a decision. Therefore, the seventh consciousness must make decisions based on direct perception (valid direct cognition). Hence, only when the evidence is conclusive and free of doubt will the manas be willing to believe, because its own wisdom is insufficient; only when the ready-made sense objects and matters of principle are laid out before Him will He be willing to believe. He Himself cannot carry out detailed comparison and imagination, because His wisdom for concrete analysis is insufficient.

Therefore, when encountering any matter, if we want the seventh consciousness to accept or affirm it, there must be sufficient evidence. This requires the mind consciousness to carry out meticulous thinking and analysis and to produce persuasive grounds. In this way, contemplative practice (vipaśyanā-caryā) and systematic organization of thought through deliberation become especially important. If the manas's wisdom were also complete, we would not need to go to such great lengths in learning Buddhism.