Abstract: This article argues that Christine Korsgaard's conception of self-constitution can be historicized by considering the impact of actual humans on our reflective activity. Because Korsgaard bases her argument on a philosophy of action rather than of intention (as Kant does), and our actions must always be concrete, the article argues that the principles for action which we develop in reflection are likewise responses to concrete human demands. It further interprets the types of demands humans make on each other as the expression of historical circumstance rather than as transcendentally anchored. The notion of universal respect that reflection seeks to achieve is thus seen as developing by a self-correcting process of concrete human interaction. Finally, the article concludes that there can be no metaphysical proof of morality, since morality develops through human interaction that seeks to approximate the idea of respect for persons.