成唯識論述記 5.68

5.68

述曰：下破前非。其有兩種：一、諸識不俱難；二、色、心無異難。下初難也。說此與彼為此依者，即是要有開導力故。一身八識既容許有俱起之理，如何自識與他類識為開導依？開避彼處，引導令生，要相有力。他現生處不障我路，非如自前心，如何他識與此為依？如薩婆多師六識不俱起，心相障故可互為依。今既俱生，應無開導。

The Commentary states: Below is the refutation of the previous errors. There are two kinds: 1. the objection that multiple consciousnesses would not be co-arising; 2. the objection that form and mind would be indistinct. Below is the first objection. To say that this and that serve as this basis is because there must be the efficacy of opening and guiding. Since the eight consciousnesses within a single body are admitted to arise simultaneously, how could a consciousness of one's own category serve as the opening-and-guiding basis for a consciousness of another category? Clearing a path for it and guiding it to arise requires an efficacious mutual obstruction. Where another presently arises, it does not obstruct my path, unlike one's own preceding mind; how could another consciousness serve as a basis for this one? For the Sarvāstivādins, the six consciousnesses do not arise simultaneously, and because minds mutually obstruct each other, they can mutually serve as bases. Now, since they arise simultaneously, there should be no opening and guiding.