Jewel of Reflection on the Truth about Epistemology is here translated and explained in an invaluable contribution to the history of knowledge, making available in English the very best within the traditions of philosophical speculation and argument in India and Sanskrit over more than twenty centuries. The "Jewel" distills the best arguments and most important positions of the past and provides the dominant focus for later philosophic reflection. The achievement of a great 14th-century logician, Gangesa Upadhyaya ("Professor Gangesa"), the Tattva-cinta-mani is a masterpiece of world philosophy, impacting in classical India not only philosophy but also literary criticism, jurisprudence, and medical theory for centuries. Among scholars, it is commonly counted-with perhaps one or two Buddhist treatises and one or two in Vedanta-among the top four or five philosophic works in the whole long history of classical Indian civilization (from 500 bce to the modern period). This three-volume edition of the work marks the first time time it has been translated into English in its entirety. Becoming the focal point of the long-running Nyaya school and canonized in Sanskrit literature, it is famed, across many schools of philosophy, for cogency of argument and consistency of analysis. Focused on four "knowledge sources" recognized in Nyaya, the text covers the epistemology of perception, inference, analogy and testimony in four chapters. In this landmark translation, Stephen Phillips provides an English-speaking audience all four parts with readable translations and running commentary. He contextualizes, analyzes and translates the text into understandable prose targeting especially those working in analytic philosophy but also anyone unfamiliar with Nyaya who may want to see and make use of its findings now accessible as never before.