In this article, I show that the assumptions underpinning John Rawls's so-called “duty of civility” ought to lead one not to affirm the duty but to reject it. I will begin by setting out in its essentials the content and rationale of the “duty of civility,” which lies at the heart of Rawls's ideal of public reason. Secondly, I will argue that the very premises allegedly underpinning the duty of civility—namely, the values of reciprocity and political autonomy, and the burdens of judgment—in fact rule it out. Thirdly, I will suggest that if my argument against the duty of civility is correct, then one recent attempt to salvage political liberalism and reasonableness from the charge of incoherence fails. Finally, I draw some challenging lessons from our discussion for political liberalism and the liberal tradition as a whole.