成唯識論述記 3.218

3.218

述曰：三．四二分由取自體，故現量攝，具所、能緣，恒但四分，不減不增，無無窮過。此中有難，如得及生，得得非得，生生非生，法不立第四得及生，何妨見分緣相及自證，不立第四分？此不應然，此能緣慮有量定故，彼但成就生長功能，非緣慮法，無量相違。據功能別，名為「非即」；四用一體，名為「非離」。又說四分能、所緣異，不可言「即」；無別種生，一體用異，故名「非離」。

The Commentary states: Because the third and fourth parts grasp their own entity, they are subsumed under direct perception; possessing both what is cognized and what cognizes, there are always only four parts, neither decreasing nor increasing, and free from the fault of an infinite regress. Here there is an objection: Just as with acquisition (prāpti) and arising (jāti)—where acquisition acquires non-acquisition, and arising causes non-arising to arise—phenomena do not establish a fourth acquisition or arising; what prevents the darśanabhāga from cognizing both the nimittabhāga and the svasaṃvittibhāga without establishing a fourth part? This should not be so; for this cognizing and reflecting has a fixed status as valid cognition, whereas those merely accomplish the function of generation and growth without being cognizing and reflecting phenomena, so there is no contradiction between valid cognitions. Based on the distinction of functions, they are termed 'not identical'; because the four functions share one entity, they are termed 'not separate'. Moreover, it is said that because the four parts differ in what cognizes and what is cognized, they cannot be called 'identical'; and because they do not arise from separate seeds, sharing one entity with distinct functions, they are termed 'not separate'.