This article offers an account of the understanding citizens need in order to justify moral principles in the public sphere and it identifies an important role for moral education in the promotion of that civic understanding. I develop this account through a contrastive analysis of Phillip Kitcher's conception of public knowledge and Jurgen Habermas' Discourse Ethics. Kitcher is focused on the social conditions necessary for the circulation of scientific knowledge in advanced democracies; the analysis offered in this article expands on what Habermas and other deliberative democrats claim are epistemic conditions necessary for the construction and circulation of moral understanding. I use this account to critically assess public policy that aims to "get around" public deliberation by using strategies derived from behavioral economics in order to shift civic behavior in specific (moral) directions. Finally, I specify how such strategies have the potential to undermine moral understanding in the public sphere and I argue for a central role for moral education in mitigating such effects.