This essay examines whether the Catholic magisterium's use of Aquinas to condemn homosexual acts is actually Thomistic. Rather than being aligned with the magisterium, Aquinas advances a moral epistemology better illuminated by the work of philosopher Judith Butler. Deploying Butler as a means of immanent critique, I show how magisterial attempts to argue against lesbian and gay sex fail on their own terms. Reading Aquinas alongside Butler shows us why we need not choose between fidelity to Thomistic natural law and (...) affirmation of lesbians and gays. (shrink)