Ken Zaretzke in the First Things blog on the logical fallacies under-girding much of the marriage debate:
"...Same-sex marriage is built on a foundation of question-begging and caricature. It’s stunning how much the advocates of SSM beg the question of whether opposite-sex couples and same-sex couples are similarly situated with respect to marriage–their talk of “marriage equality,” in this sense, is simple-minded propaganda. It’s also impressive how they think they can ignore a nuanced understanding of the connection between marriage and procreation, preferring inaccurate and even ridiculous caricatures of this all-important connection.
To give an example, procreation is not the sine qua non of marriage, as the author of what Richard Posner has described as “the best book on same-sex marriage” calls it. If even the most sophisticated supporters of SSM are prone to such inaccuracies, what are we supposed to think? (Procreation is the raison d’être of marriage–a very different thing from sine qua non. Boiled down, this means the general fact of procreation is the reason for the existence of the institution of marriage–or that the marriage institution minus procreation as a general fact about that institution is meaningless, an empty shrine.)"
William Haun joins in:
"...The logical problem same-sex marriage advocates face at that juncture is that marriage is a legal institution, and government action requires at least a rational basis to proceed. So, rather than answer why society should have marriage laws if marriage is solely personal, they make empty arguments about “equality” and “civil rights.” This particular language is able to stifle serious responses out of fear of being branded a modern-day Bull Connor. But that is not argument, it is question-begging–the logical equivalent of an emperor without clothes. Our society will be able to point this out when marriage defenders explain why the law can make some distinctions among people so long as they’re rationally based (as racial distinctions were not), and why a rational basis so exists with marital unions. Re-educating society may not change values, but as John Adams observed, facts are stubborn things–and marriage should be explained as the result of the facts of life."