One of Fichte's most important ideas - that nature can place limits on our ability to govern ourselves, and that anyone who values autonomy is thereby committed to the value of basic research and of the development of autonomy-enhancing technologies - has received little attention in the interpretative literature on Fichte, and has little currency in contemporary ethics. This volume aims to address both deficits. Beginning from a reconstruction of Fichte's theory of rational agency, this volume examines his arguments for the thesis that rational agency must have two constitutive ends: substantive and formal independence. It argues for a novel interpretation of Fichte's conception of substantive independence, and shows how Fichte's account of moral duties is derived from the end of substantive independence on that conception. It also argues for a new interpretation of Fichte's conception of formal independence, and explains why the usual understanding of this end as providing direct guidance for action must be mistaken. It encompasses a systematic reconstruction of Fichte's first-order claims in normative ethics and the philosophy of right.