In this essay I sketch a philosophical argument for classical liberalism based on the requirements of public reason. I argue that we can develop a philosophical liberalism that, unlike so much recent philosophy, takes existing social facts and mores seriously while, at the same time, retaining the critical edge characteristic of the liberal tradition. I argue that once we develop such an account, we are led toward a vindication of “old” (qua classical) liberal morality—what Benjamin Constant called the “liberties of the moderns.” A core thesis of the paper is that a regime of individual rights is crucial to the project of public justification because it disperses moral authority to individuals thus mitigating what I call the “burdens of justification.”