Dignāga’s Logic of Invention∗

In this paper the Indian Buddhist logic of the Middle Ages is connected to methodological aspects of logic, especially to the idea that logic can serve as an organon, e. g., as a tool for discovering novelties. Research on this idea can be characterized by questions like “Is there a logic of invention?”, “What is the role, if any, of deductive logic in creative processes?”, “What is the role of logic in philosophy of science, especially in a philosophy of science which takes the context of discovery into account?” In Europe the sensitivity for the great efforts of Indian logic is mainly due to J. M. Bocheński’s appreciation for it as expressed, e. g., in his Formale Logik of 1956. Bocheński regarded Dignāga, who lived from about 480 to 540 A. D., as the Indian Aristotle. For Bocheński the Indian experience was even one of the cornerstones for his reflections on a general theory of the historical development of logic. The development of logic was in fact not a continuous one starting with Aristotle and ending with modern mathematical logic, but a series of ups and downs, full of unconscious re-inventions, and it started from a double root, the ancient Greek and the ancient or medieval Indian logic. It might be worthwhile to sum up Bocheński’s results, despite the fact that most of his positions have been disputed in the last 45 years of research. Bocheński devoted the sixth (and final) part of his Formale Logik to the “Indian Variety of Logic”. He stressed that logic arose in two distinct cultural areas, in the Occident and in India, and the Indian Buddhist logician