Rousseau’s chapter “Of Civil Religion” has perplexed readers ever since the publication of the Social Contract. For the book’s earliest readers, the chapter was a sign of its author’s theological heresy even if contemporary readers are likely to take a more benign view of Rousseau’s intention. The question I pose is why the formula for the laws and institutions set out in the earlier parts of the Social Contract requires additional support in the form of the religious beliefs examined in the penultimate chapter. I want to suggest that this chapter represents a nod in the direction of Rousseau’s political realism in his acknowledgement that civil religion remains an indispensable part of the education of republican citizens.