Douglas Laycock, a leading scholar of religious liberty, has staked out a middle ground position in the looming confrontation between gay rights and religious rights. He calls his approach “liberty and justice for all.” “Same-sex civil marriage is a great advance for human liberty. But failure to attend to the religious-liberty implications will create a whole new set of problems for the liberties of those religious organizations and believers who cannot conscientiously recognize or facilitate such marriages,” writes Mr. Laycock, a professor at the University of Virgini...