Origin and Development of Indian Logic and Buddhist Logic

It is very difficult to give satisfactory chronological accounts of the rise and growth of Indian Logic for the reason that the texts, which the science of logic or various logical terms have been mentioned or used, have so far failed to be dated with certainly. The earliest reference to logic or science of debate seem to be contained in chndogya upanisad where Nrada includes among the disciplines studied by him, one called vkovakyam (Ch. U.7.1.2). The term is explained by Sankarcrya as meaning logic (tarkasstra), but it seems to signify the art or science of debate. Among later works the arthasstra of Kautilya (400 B. C. ) mentions logic under the name of anvksik, which is the first among the four disciplines, alluded to by him (arthsstra 1-2. p.6). Perhaps even in those days, as now, the followers of reason or logic were not very orthodox people. Arthasstra says that a person well versed in the art of governing ought to know logic also. Next important references are to be met with in the kathvatthu (300 B. C. ), which is a part of the abhidharma piaka in Buddhism. The work mentions Anuyoga (inquiry), harana (illustration), patia (proposition). In the Mahbhrata not only the term Upanayana (application of reason), Niggaha (Nigraha-humilation of or defeat), Anvksik, etc. have been used, but also there is a reference to the five member sentence or speech whose strong and weak points were thoroughly known to Nrada2 In vanaparva, a chapter of Mahbhrata there is a story about the controversy between vandi, the court philosopher of king Janaka, and Astvkra, a young scholar. The story is illustrative of the fact that the rules of controversy were known at the time of Mahbhrata. It is certainly true that rules of controversy cannot be identified with the theory of logic.