瑜伽師地論略纂 2.24

2.24

「又一剎那五識生已，從此無間必意識生」等者，此說五識率爾心後，定有尋求。尋求之後，若時散亂，生即不定；若不散亂時，決定心生。染淨心生，由分別及先所引二因故。起分別者，曾未得境，今分別故。　先所引者，前已得境，諸悉故生。意由二因，五唯由一。此說五識等流，意等流亦爾。此中唯說尋求後不定，不說決定後及染淨後不定，理皆通故。然今不說率爾後生尋求不定，故知率爾後定起尋求。〈決擇〉亦言：在定，耳識率爾聞聲，若有希望，後時方出。希望即是尋求心故。餘義如〈五心章〉說。

As for "Furthermore, when the five consciousnesses have arisen for one moment, immediately following this, the mental consciousness will definitely arise," etc.: this states that after the initial reactive mind (rate-er-xin) of the five consciousnesses, there is definitely investigation. After investigation, if there is distraction at that time, its arising is not fixed; if there is no distraction, the mind of determination arises. Defiled and pure minds arise due to two causes: conceptual discrimination and prior inducement. That conceptual discrimination arises is because, regarding an object not previously attained, it now discriminates it. As for prior inducement, regarding an object previously attained, it arises because it is familiar. The mental consciousness is due to two causes; the five [consciousnesses] are due to only one. This refers to the equivalent outflow of the five consciousnesses, and the equivalent outflow of the mental consciousness is also like this. Here it is only said that after investigation it is not fixed, without saying that after determination and after defilement and purity it is not fixed, because the principle applies to both. However, now it does not say that after the initial reactive [mind] the arising of investigation is not fixed; thus we know that after the initial reactive [mind], investigation definitely arises. The Viniścayasaṃgrahaṇī also says: While in meditative absorption, the ear consciousness initially hears a sound; if there is anticipation, only later does it emerge [from absorption]. Anticipation is precisely the mind of investigation. The remaining meanings are as explained in the "Chapter on the Five Minds".