Patrick Lee is the John N. and Jamie D. McAller Professor of Bioethics at Franciscan University of Stuebenville. He writes in Public Discourse that "the conjugal conception of marriage is just and coherent; the same-sex marriage proponents' unjust and incoherent":

The “marriage equality movement”: that’s the name chosen for themselves by same-sex “marriage” supporters. The implicit argument is that the state’s granting marriage licenses only to opposite-sex couples is undue discrimination. The claim has an initial plausibility: the state grants a marriage license to John and Mary but not to Jim and Steve. Isn’t that unequal treatment? But this charge, I will show, rests on a profound confusion about both marriage and equality. A state’s recognition that marriage is only between a man and a woman is not unjust. What’s more, a state’s endorsement of same-sex “marriage” does create an arbitrary and invidious discrimination.