This book, of numerous references, is an encyclopedia of logic, metaphysics, ethics and theology and represents the history of Indian Philosophy of a particular period. A popular saying credits the author, Jayanta, with the reputation of being a master-scholar of Indian logic. No study of Indian logic can be considered to be complete without having recourse to this work. The main task of the author in this book is to defend the views of Vatsyayana as expressed in his Nyaya-bhasya on the sutras of Gautama against the criticisms offered by the adversaries. He has criticised the views not only of the Buddhists but also of the Grammarian bhartrhari and the Mimamsakas-Kumarila and Prabhakara. his condemnation of the Prabhakaras as the plagiarists who borrowed from the Buddhist show his intimate knowledge both of the Buddhists and the mimamsa ka schools. In his lengthy discussion on the pramanas in this volume, he has refuted the hypothesis of the Bhattas and the prabhakaras. Thus the book provides knowledge not only of the details of the Nyaya School but also of the systems of logic followed by the rival schools.