________________ INTRODUCTION The B by Nagadatta of the Vatsiputriya sect, and attained erudition in the Tripitaka of the Hinayana. Afterwards he became a disciple of Acharya Vasubandhul with whom he studied all the Pitakas of the Mahayana. A few years later, he was invited to Nalanda, where he defeated his opponents and won them over to the doctrine of the Buddha. Since he had refuted chiefly the Tirtha controversialists, he was called a 'Fighting Bull' or a 'Bull in discussion' (tarka-pungava). He lived a considerable part of his life in Andhra. He is said to have died in a solitary wood in Orissa.'2 Lama Taranatha has mentioned these facts about the life of Dinnaga.. The following are the works of Dinnaga on Logic :(1) Pramana-samuchchaya, (2) Hetu-chakra-samarthana, (3) Pramana-samuchchaya-vritti, (4) Nyaya-dvara or Nyayamukha, (5) Alambana-pariksha, (7) Alambana pariksha-vritti, and (8) Trikala-pariksha. The Buddhist works on logic composed before the Pramanasamuchchaya of Dinnaga discuss the problem of pramana (valid knowledge or means of valid knowledge) either very casually or not at all. They primarily deal with the subjects relating to discussions. The Vada-vidhi or Vada-vidhana, Upaya-bridaya, Tarkasastra and Nyaya-mukha, primarily concern themselves with the study of jati and nigraha-sthana and the merits and defects of discussion. The Vigraha-vyavartini of Nagarjuna questions the very existence of pramana and shows that it is incompetent to prove anything. Even the Nyaya-sutra is not a work on pure logic, since it is concerned mainly with the topics of discussion. There is no work composed before Dinnaga dealing with the * problem of pramana exclusively. This being the case, the title conferred on Dinnaga as the Father of Medieval Indian Logic is well deserved. Granting that Dinnaga is the Father of Medieval Indian Logic, it goes without saying that he is the father of Buddhist logic. The new method of Dinnaga was followed both by the . 1 The Naya-chakravritti mentions Dinnaga as a disciple of Vasubandhu, 2 S. Vidyabhusbana--History of Indian Logic, p. 272.
