 In the Dharmakīrtian system, the “elimination of superimpositions” is tantamount to ascertainment (nges pa). This is to be understood in the framework of the “apoha” (lit. “exclusion”) theory: any positive determination proceeds via the elimination of what is other. For instance, determining a patch of colour as “blue” does not consist in identifying some blue property or some blueness shared by blue things, but in differentiating this patch from the “other,” namely from things that are not-blue. Determination as “blue” amounts to eliminating actual superimpositions of “non-blue” (for instance, if one thought that the patch was yellow), or potential ones; in the former case, the determination eliminates a mistaken judgment and replaces it by a correct one, in the latter it prevents the subsequent arising of a mistaken judgment. Both sides of the process, superimposition and its elimination, are, for Dharmakīrti, exclusively conceptual operations.