Synopsis This book presents a readable translation and philosophic commentary on a crucial and difficult text of Navya Nyaya and classical Indian logic. The inferential undercutter's significance is explained within the context of Nyaya's theory of knowledge, which had wide influence in the late classical culture, from philosophy to jurisprudence and aesthetics. Gangesa, the commonly recognized founder of "New Logic," is shown here to be an epistemologist and logician of the very first order. The book has been written for philosophers who are unfamiliar with Nyaya and Sanskrit philosophic terminology as well as for Indian philosophy specialists. An introduction places Gangesa's work within historical and ideative context, and a glossary explains his technical terms.