...the parallel with the Matrix scenario is even closer than what I’ve said so far suggests, for the implications of “same-sex marriage” are very radically skeptical. The reason is this: We cannot make sense of the world’s being intelligible at all, or of the human intellect’s ability to understand it, unless we affirm a classical essentialist and teleological metaphysics. But applying that metaphysics to the study of human nature entails a classical natural law understanding of ethics. And that understanding of ethics in turn yields, among other things, a traditional account of sexual morality that rules out “same-sex marriage” in principle. Hence, to defend “same-sex marriage” you have to reject natural law, which in turn requires rejecting a classical essentialist and teleological metaphysics, which in turn undermines the possibility of making intelligible either the world or the mind’s ability to understand it. ---Feser