成唯識論演祕 3.837

3.837

問：如佛法者對聲論師立聲無常，聲有法宗，不為其過。真性有為既是有法，何故疏等判為過耶？以有法中不言空故。

Question: When a Buddhist establishes sound as impermanent against a Śabdavādin, having sound as the subject (dharmin) of the thesis entails no fallacy. Since real conditioned phenomena are the subject, why do the Commentary and other works judge it to be fallacious? Because 'empty' is not stated within the subject.