A New Jersey judge’s contorted and nonsensical decision that the state is responsible for the federal government’s failure to recognize same-sex marriage highlights the irrationality that permeates the campaign for “marriage equality.” One of the most striking features of the campaign for same-sex marriage has been the prominence of its assault on reasoning itself. The logical relations of legal categories with one another, as those categories represent persons, their interactions, and their rights and duties, are at the heart of all legal decision-making and ideally inform legislative and administrative policymaking as well. But the impulse to redefine marriage so that...