Understanding the importance of post- Buddhism Buddhist requires not only a serious study of stagnation, but also a serious study of Sanskrit Buddhist texts, as well as the texts of those Vedic traditions, whose predecessors have been refuted by great Buddhist philosophers.Not only Buddhist logic but also the genius of Didnag and his father, the father of medieval justice, is acknowledged. Didnag or Diggag was born near Kanchipuram around 400 AD. His books 'Nyayapravesh' and 'Nyayadwar' are well known, as well as 'Praman Samuchaya', 'Alann Pariksha', 'Hetuchakradamru', 'Nyayamukh', 'Hastaval Prakarna', 'Arya Pragya Parmita Vivan' and 'Aryaan Pariksha' available in Chinese and Tibetan. 'Abhidharma Koshamarm Pradip 'are some of his famous books on logic.

Didnaga's work laid the foundation for the development of intermittent logic in India and created the first system of logic and epistemology. According to Georges B Dreyfus, his school of philosophy brought about an Indian epistemological turn that became a standardized structure in India, Tibet and other countries. Didnaga's ideas influenced later philosophers, such as Dharmakirti and Hindu thinkers. 'Direct' and 'Conjecture' in Buddhist logic. 

Later Indian philosophers had a broad view on rational reasoning and understanding of language. According to Richard P Hayes, "Anyone wishing to understand the historical development of Indian thought must be familiar with Didnag's arguments and conclusions." Didnag has written more than a hundred dissertations on logic. Acharya Dharmapala had studied Buddha Dhamma at Didnaga. Acharya Dharmapal later became the Chancellor of Nalanda University.

Reference : History of Buddhism in India.