This chapter is devoted to the Kantian background of Fichte’s ethical theory, and argues that Fichte shares with Kant’s account of morality three key elements: first, a formal criterion of moral judgment (universal law or law of nature), second, a substantive value (humanity as end in itself) motivating obedience to duty and capable of grounding specific classes of ethical duty, and third, a conception of an ideal of moral perfection in a community of rational beings (the realm of ends). The chapter argues that, while Fichte’s ethics contains all three of these things (or at least analogues to them), Fichte departs from Kant’s ethics in three crucial ways. The first is Fichte’s alternative derivation of the criterion of judgment in a theory of conscience. The second is his alternative conception of classes of duty in a transcendental theory of the embodied, intellective, and intersubjective aspects of human agency. And the third is Fichte’s alternative account of our communicative and cooperative relations to others in a theory of social perfection.