In recent years, neo-Aristotelian ethical naturalism has received significant critical attention. Proponents of this view, such as Philippa Foot, Rosalind Hursthouse, and Michael Thompson argue that we should conceive moral goodness as a form of natural goodness. On the view they defend, the goodness of moral virtue is similar to the goodness of deep roots in an oak tree: just as an oak tree needs deep roots for proper nourishment, human beings need the virtues in order to flourish. To many of its adherents, what recommends ethical naturalism is its ability to accommodate both the objectivity of moral judgments and their practicality. On a naturalist view, moral judgments are grounded on objective facts about our nature; and we are motivated to act morally because that promotes our own flourishing. Yet critics have argued that ethical naturalists cannot meet both requirements and do justice to the rational or self-conscious character of human life and action. This is because what distinguishes human life from the life of other natural creatures is that we act for reasons—i.e., we act based on an understanding of what is good or required—and in some cases this involves distancing ourselves from our nature. Critics claim that ethical naturalists are faced with a dilemma. They can hold on to their naturalist credentials but fail to capture the rational or self-conscious character of human life, an option that makes it difficult to explain the practicality of moral judgments. Or they can give up their naturalist credentials and do justice to the rational and self-conscious character of human life, an option that makes it difficult to accommodate the objectivity of moral judgments. My aim is to contribute to this debate by drawing on Kantian and post-Kantian ethics (focusing on Kant, Fichte, Schiller, Schelling, and Hegel). I will argue that we can solve this dilemma by developing a conception of human nature derived from German Romanticism, according to which we perfect ourselves by bringing the natural and rational aspects of our nature into harmony in ethical action, and in doing so constitute the human life-form. I call the position that I defend Post-Kantian Moral Perfectionism.