This book examines Aristotle's method in ethics from the vantage point of his broader conception of philosophy. Joseph Karbowski challenges longstanding dialectical orthodoxy and argues instead that, in his ethical treatises, Aristotle is seeking the first principles of a demonstrative ethical science, a science of human goodness, using an ethically adapted version of the method described in the second book of his Posterior Analytics. Part I of this volume develops a novel interpretation of Aristotle's conception of philosophy, which highlights its ambition to scientific knowledge (episteme) and its flexible approach to philosophical inquiry. Part II then demonstrates Aristotle's scientific and flexible approach to philosophy at work in his ethical treatises. The book shows how the aspiration to scientific knowledge is compatible with Aristotle's remarks about ethical precision, the practical aim of ethics, and the particular orientedness of phronesis (practical wisdom).