evaṃ manyate yadyapi vivakṣāmātreṇa saha kāryakāraṇabhāvo niścito vivakṣāviśeṣeṇa tu parasantāne samayādṛte na niścetuṃ śakyata ityatastanniścayāya samayaḥ kriyate /
[The answer] is thought to be thus: Although the causal relation with mere vivakṣā in general is ascertained, the [relation] with a particular vivakṣā in another's mental continuum cannot be ascertained without convention; therefore convention is made for its ascertainment.