  Uddyotakara in his Nyāya-sūtra commentary incorporates Dignāga’s ideas to formalize many of Vātsyāyana’s informal inferences. The Nyāya philosopher owes almost everything to his Buddhist adversaries, as opposed to his Nyāya predecessors, but he does criticize and alter what he sees as the certification conditions of inference as a knowledge source, combining Dignāga’s second and third tests into a single requirement, knowledge of pervasion. He also adds a third condition, the subject’s having to “reflect” and put the information together, so to say: