  In providing arguments in favor of the conclusions accepted by Mādhyamikas, Bhāvaviveka followed the example set by Dignāga (fl. ca. 510), a Buddhist whose principal contributions were in the area of epistemology and logic. Dignāga, following with some modifications philosophers of the Brahmanical Nyāya school, had devised a canonical form of presenting arguments, which consisted in identifying a topic (pakṣa) and reasoning on the basis of an observed feature of the topic that it also had another feature not currently available for direct observation. The stock example given in Indian logic is that if a particular mountain is the topic, one can reason on the basis of observing smoke associated with that mountain that there is also a fire associated with that mountain. Attributing an unobserved feature to a topic on the basis of an observed feature is legitimate only if one has previously observed the feature used as evidence together with the feature being inferred, and if one has never seen the feature used as evidence in the absence of the feature being inferred. Dignāga’s method of presenting an argument consists, then, in stating a topic (pakṣa) and a property used as evidence (sādhaka-dharma) for a property to be established (sādhya-dharma). Bhāvaviveka followed this method in arguing for the conclusions of which he claimed Mādhyamikas are convinced; he also criticized Buddhapālita for failing to follow Dignāga’s method.