 Though the canonical syllogism is central to the development of reflection on argument and reasoning in preclassical and classical India, other forms of argument were also recognized as good. One form, as mentioned above, is reductio ad absurdum (prasaṅga). Others include suppositional reasoning (tarka) (Bagchi 1953) and a form of reasoning akin to what contemporaries would call disjunctive syllogism (arthāpatti) (Keating (ed.) 2020). At the same time, there are forms of argument, different from the fallacious rejoinders and specious reasons, which were also regarded as bad. They include arguments which lead to an infinite regress (anavasthā), mentioned above, as well as various forms of circularity. Finally, there are two important forms of argument: one peculiar to Buddhists, known as the tetralemma (catuṣkoṭi), and the other peculiar to the Jains (syādvāda).