大乘百法明門論解 1.46

1.46

They are named according to their faculties because they possess five senses [of the relationship], namely: depending on, arising from, belonging to, assisting, [and being shaped by the faculty]. For example, with the exception of the consciousness arisen from a faculty, the other four are all consciousnesses dependent upon a faculty, etc., which is a tatpuruṣa compound (依主); 'faculty-arisen' is also a tatpuruṣa compound (依士). Although the collection of six consciousnesses all evolve depending on the manas, here this [sixth] is named according to its exclusive faculty, the manas, as 'depending on and arisen [from it],' so there is no confusion with the five consciousnesses. This is stated, moreover, in view of the stage where one has not yet attained mastery; or else it is named 'mental consciousness' (mano-vijñāna) solely because it depends on the manas. When distinguishing the origins of the names of consciousnesses, the [terms] citta and manas are not parallel cases.