唯識二十論述記 2.225

2.225

述曰：前難覺識應知境無，此顯不知實境定有。覺、夢二境俱非有，即知夢識境成無，覺不自知無異於夢，故知覺識境實有。量云：世覺時識外實境有：許異夢故；如自真智。不言世覺，相符極成，亂真覺故。因不言許，隨一不成，生死大乘說為夢故；或簡五識，不行夢故；或顯異於眠時夢故，喻不言自，其體便闕。大乘真智無外境故，若說大乘真智為喻，所立不成，為此等過，宗等各簡。

Commentary: The previous objection was that waking consciousness should know that its object is non-existent; this shows that not knowing it means real objects are definitely existent. Objects of both waking and dreaming are non-existent, yet the consciousness that knows the dream realizes its objects are non-existent; waking does not know by itself and does not differ from dreaming, so one knows that the objects of waking consciousness are real existents. The inference is: External real objects of worldly waking consciousness exist; because it is conceded to differ from a dream; like one's own true cognition. If one does not say 'worldly waking', there would be the fault of proving what is already established, because it confuses true awakening. If the reason does not say 'conceded', there would be the fault of being unestablished for one party, because in the Mahāyāna saṃsāra is spoken of as a dream; or it qualifies the five consciousnesses, because they do not operate in dreams; or it shows a difference from dreams during sleep. If the example does not say 'one's own', its essence would be defective. Because the Mahāyāna true cognition has no external object, if one spoke of Mahāyāna true cognition as the example, the probandum would be unestablished. For faults such as these, each of the proposition and the rest is qualified.