Vaisesika Sūtra 4.2.02

pratyakṣāpratyakṣāṇāṁ saṁyogasya apratyakṣatvāt pañcātmakaṁ na vidyate ॥2॥

The conjunction among visible and invisible is not perceptible, hence, ātman combined with five elements does not come to light.