成唯識論述記 2.19

2.19

述曰：此中量云：所執極微應可分析，應非實有；有方分故；如麁色等。此二比量破經部師、諸計極微有方分者，然，方即分，更無有分故。《二十唯識》云：「極微有方分，理不應成一。」

The Commentary states: The formal inference here is: 'The posited atoms should be susceptible to analysis, and should not be substantially real; because they possess spatial parts; like coarse matter and the like.' These two formal inferences refute the Sautrāntika masters and all who posit that atoms have spatial parts. However, the direction is itself the part, and there is no part beyond it. The Viṃśikā says: 'If an atom has spatial parts, logically it cannot be a single unity.'