In his concise and ambitious book, Gareth B. Matthews explores the implications of doing philosophy in the first person. He focuses on the most notable attempts in the history of philosophy to take this perspective: Augustine's Confessions, perhaps the first significant autobiography in Western culture, and Soliloquies, a dialogue between himself and reason; and Descartes's Meditations and Discourse on Method. "By examining the first-personalization of philosophy in these two historical figures," he writes, "we can learn something important about our own philosophical options, and about those of any other thinker who dares, philosophically, to say 'I.'" Matthews starts by considering the 'I' that knows - and how it can know what it knows - in Cartesian and Augustinian thought. He goes on to explore the problems that dreams and other cognitive states apparently divorced from the "real world" pose for understandings of identity and knowledge. He then discusses the potentially authoritative bases for philosophical claims made in first-person philosophizing, and closes by considering how themes, concepts, and lines of reasoning can take on related yet clearly different forms in the work of these two philosophers. This book will be of great interest to philosophers of mind and epistemologists, historians of philosophy and their students, philosophers of religion, and theologians, as well as specialists in Cartesian and Augustinian thought.