- Dignāga(as the main philosopher being discussed)
- A Buddhist philosopher from around 480-540 CE who made major contributions to how we know things are true, particularly focusing on perception and reasoning.
- Indian philosophical schools(as the various philosophical communities influenced by Dignāga's ideas)
- Different traditions of philosophy that developed in ancient and medieval India, each with their own ideas about truth, knowledge, and reality.
- Logic(Introduced as an overarching category encompassing rhetoric, poetics, sophistical syllogistic, dialectic, and demonstration.)
- The universal instrument for distinguishing between the true and the false, whose nature varies according to its objects and ends.
- hetu(Nyāya inference structure)
- The reason property used to infer the presence of the sādhya in the pakṣa
- locus(Buddhist atomic theory critique)
- The spatial location occupied by an atom; the argument treats locus as exclusive — one atom's locus cannot simultaneously be the locus of another distinct atom.
- pakṣadharmatā(One of the standard conditions for valid inference)
- The condition that the locus of inference possesses the inferential sign (h); distinct from pakṣaṭā
- valid(Contrasted with the proof-theoretic notion of deducibility)
- A model-theoretic notion indicating that a conclusion is true in every model in which the premises are true