成唯識論述記 6.78

6.78

述曰：亦應勝解應自無力為勝發起，應復待餘法方能勝發；是心所故；如汝作意。若許勝解復待餘者，便有無窮失。若勝解不待餘，作意等亦應爾故，但以印可為勝解相，故疑心中不得起也。若言：心起決定有之，但相微隱何以知也？若以餘位有，比此亦有，即餘位有尋、伺，上地亦應有。但相隱故不可知者，如是大失，即唯決定境起勝解也。

The Commentary states: Resolve should also, by itself, lack the power to be a superior initiator, and should again depend on other dharmas before it can superiorly initiate; because it is a mental factor; just like your attention. If you accept that resolve again depends on another, there would be the fault of infinite regress. If resolve does not depend on another, attention, etc., should likewise be so. Therefore, it is solely endorsement that is the characteristic mark of resolve; hence, it cannot arise in a doubting mind. If they say: 'When the mind arises, [resolve] is definitely present, but its mark is subtle and hidden'—how would one know this? If, because it exists in other states, you infer by analogy that it also exists here, then since vitarka and vicāra exist in other states, they should also exist in the higher stages. If one says that it cannot be known merely because its marks are hidden, this is a great fault; thus resolve arises only with respect to a determined object.