唯識二十論述記 2.171

2.171

述曰：此正申難。如世人言：我今見色，乃至觸觸。若無識外實色等境，寧有此覺？我今現證如是色等，此覺既非無，外色等定有。總言「覺」者，心、心所法之異名也。今此言「覺」，謂現量智，非唯是慧。因明者說言證智者，心、心所法之總名矣。故舊論云：「如此證智，云何得起？」《成唯識》中亦有此難：「色等外境分明現證，現量所得，寧撥為無？」

The commentary says: This directly presents the objection. Just as people in the world say: 'I now see form,' and so on up to 'touch tangibles.' If there are no real objects such as form external to consciousness, how could there be this awareness: 'I am now directly experiencing such form and so forth'? Since this awareness is not non-existent, external form and so forth must definitely exist. In general, 'awareness' (buddhi) is another name for mind and caittas. Here, 'awareness' refers to direct perceptual cognition, not solely to wisdom. Epistemologists say that 'cognition of realization' is a general name for mind and caittas. Therefore, the old translation of the treatise says: 'How could such an understanding cognition arise?' This objection also appears in the Cheng weishi lun: 'External objects such as form are distinctly and directly experienced, being obtained by direct perception; how can they be rejected as non-existent?'