Dharmakīrti (6th century AD) is counted among the most significant and innovative Indian philosophers. This Buddhist thinker attempted to meet the challenges of a new era in Indian history marked by brahmanical hostility towards Buddhism as well as profound political, economic, religious, and institutional transformations, leading to the emergence of overt interreligious polemics. In order to defend and promote the pristine truth of Buddhism as the only rational path towards salvation, Dharmakīrti elaborated, partly on the basis of Dignāga’s (5th-6th century AD) epistemology, sophisticated accounts of ontology, cognition, language, action, religious authority, and truth. Far from being an axiomatically neutral and disinterested inquiry into human cognition, Buddhist epistemology (otherwise known as “Buddhist logic”) became the methodology adopted by Buddhist apologetics from the 6th century onwards. Nevertheless, one should be wary of discarding Dharmakīrti’s philosophy as a purely religious account of human cognition and action. First, because the present author is aware of no religiously neutral Western philosophy prior to the 20th century. Second, because Dharmakīrti’s views, especially on concept formation, language, and authority, can be at least partly studied independently of his own Buddhist metaphysical assumptions.