成唯識論述記 2.389

2.389

述曰：第七、有無乖角難，有二：初難後結，難中有四子段，第一、定世有無難，欲破生滅無，先破世非有。量云：去、來二世非實有體；非現在故，及非常故；如空華等。非常之言，簡無為法，此定去來無。次子段第二、生滅非依難。

The Commentary states: Seventh is the objection of the clash between existence and non-existence, which has two parts: first the objection, and then the conclusion. In the objection there are four sub-clauses: First is the objection determining the existence or non-existence of the times. Wishing to refute the non-existence of birth and destruction, he first refutes the non-existence of the [past and future] times. The syllogism is: The two times of past and future do not possess real substance; because they are not present, and because they are not permanent; like a sky-flower and the like. The phrase 'not permanent' excludes unconditioned phenomena; this determines that the past and future are non-existent. Next is the second sub-clause, the objection that birth and destruction have no basis.