yato 'nuvṛttilakṣaṇaṃ dravyam paryāyās tu vyāvṛttilakṣaṇāḥ saṃjñā nāma arthaḥ kāryam
Because substance has the characteristic of continuity while modes have the characteristic of discontinuity; [where] saṃjñā means name and artha means function.