Many Americans have long subscribed to what this Article calls the myth of the written constitution—the claim that the nation’s Constitution consists entirely of those texts that the sovereign American people have formally ratified, and the claim that the will of the American people, as expressed in those ratified texts, determines the way in which properly behaving judges resolve constitutional disputes. Drawing on two different meanings of the term myth, this Article contends that neither of those claims is literally true, but that Americans’ attachment to those claims serves at least three crucial functions. Subscribing to the myth helps to ease the tension created by the American people’s paradoxical beliefs that they are morally entitled to govern themselves and that human beings often cannot be trusted to behave in morally praiseworthy ways; it helps to ease the tension between Americans’ commitment to self-rule and their attraction to judicial supremacy; and it helps to secure the strong sense of nationhood that so many Americans deeply desire. The Article suggests that embracing the myth of the written constitution for its functional value need not be seen as a shameful act of self-delusion, despite the fictive qualities of the myth’s claims. So long as courts and scholars maintain the necessary conditions, the American people can responsibly embrace the myth as an act of “poetic faith.”