The controversy over same-sex marriage centers on whether the institution of marriage will be harmed by extending it to same-sex couples. Conservatives insist that it will and therefore argue that same-sex marriage should not be legally permitted. By contrast, liberals are mystified by the contention that same-sex marriage could even conceivably harm traditional marriage. This article shows that conservatives and liberals are both right and that they are both wrong. Conservatives are right that, in an important sense of harm, the legal recognition of same-sex marriage will indeed harm traditional marriage. Liberals are right that despite such harm, marriage should be extended to same-sex couples nonetheless. Implicit in this controversy is the question of which types of harm should be recognized as constituting reasons for and against laws in a democratic society. A corollary question is who owns and is entitled to participate in American democratic institutions. Of course, when preventing certain types of harm constitutes a compelling state interest, the state may prohibit conduct causing that harm. However, in a democratic society, harm that results only from clashing normative environments should be permitted. While perhaps satisfying extremists on neither side, this rapprochement can contribute to a cease fire between reasonable conservatives and reasonable liberals in one of the more heated battles in the so-called culture wars.