Friedrich Schleiermacher (1768-1834) is often considered the Father of Modern Theology, known for his attempt to reconcile traditional Christian doctrines with philosophical criticisms and scientific discoveries. Despite the influence of his work on significant figures like Karl Barth, he has been largely ignored by contemporary theologians. Focussing on Schleiermacher’s doctrine of sin, this book demonstrates how Schleiermacher has not only been misinterpreted, but also underestimated, and deserves a critical re-examination. The book approaches Schleiermacher on sin with respect to three themes: one, its power to transcend an intractable metaethical dilemma at the heart of modern debates over sin; two, its intended compatibility with natural science; and three, to re-evaluating its place, and so Schleiermacher’s place, in the history of theology. It solves and dissolves problems arising simultaneously from natural science, confessional theology, ethics, and metaphysics in a single, integrated account using Schleiermacher’s understudied thought from his dogmatics The Christian Faith. In contrast to the account sometimes given of modern theology as marked by a break with "Greek metaphysics," Schleiermacher’s account is shown to stand in stark contrast by retrieving, not excising, ancient thought in service of an account of sin adequate to natural science. This is a vital rediscovery of a foundational voice in theology. As such, it will greatly appeal to scholars of Modern Theology, theological ethics, and the history of Modern Christianity.