arthāntaravidhānenārthāntarasya niṣedhaṃ pratipādayitum icchatā sākṣāt pāramparyeṇa vā viruddhasyaiva vidhānāt pratipādanīyo nāviruddhasya
When one wishes to establish the negation of one thing through the affirmation of another thing, one should establish [it] through the affirmation of something that is contradictory either directly or indirectly, not through [the affirmation of] something non-contradictory.