Beginning in 1350, in regions that are now Bihar and Bengal in northeast India, there was produced a vast literature embodying a methodology that not only provides a high point in Indian philosophy but also became extremely influential in many other branches of Indian thought, including law, jurisprudence, and literary theory. This volume, the sixth in Karl Potter's monumental series, deals with that literature. Thirty-three works by fifty authors dating from 1350 to 1510 represent the philosophy of Nyaya-Vaisesika in the early stages of what was to become known as Navyanyaya, the "new" Nyaya. An extensive introduction is included. The major works treated in this volume are Gangesa's initial masterpiece, Tattvacintamani, and its remarkable commentary by Raghunatha Siromani.