This major study of Heidegger is the first to examine in detail the concept of existential truth that he developed in the 1920s. Daniel O. Dahlstrom critically examines the genesis, nature and validity of Heidegger's radical attempt to rethink truth as the disclosure of time, a disclosure allegedly more basic than truths formulated in scientific judgements. The book has several distinctive and innovative features. First, it is the only study that attempts to understand the logical dimension of Heidegger's thought in its historical context. Second, no other book-length treatment explores the breadth and depth of Heidegger's confrontation with Husserl, his erstwhile mentor. Third, the book demonstrates that Heidegger's deconstruction of Western thinking occurs on three interconnected fronts: truth, being and time. Dealing with a crucial aspect of the philosophy of one of the great thinkers of the twentieth century, this book will be important to all scholars and students of Heidegger, whether in philosophy, theology or literary studies.