vyapti
व्याप्ति vyāptiInvariable pervasion, the universal rule (such as 'wherever there is smoke there is fire') on which a valid Nyaya inference depends. Establishing it securely was one of the great labours of Indian logic.
Where this term appears
- Charvaka: the Indian materialists Philosophy
The logicians of Nyaya, in particular, built much of their elaborate theory of inference and of vyapti , invariable concomitance, in part to answer exactly this skeptic.
- What is Nyaya? Philosophy
The key that makes any of it work is the vyapti , the pervasion, the established rule that smoke never occurs without fire.