We invented marriage. Couples invented marriage. We also invented divorce, mind you. And we invented infidelity, too, as well as romantic misery. In fact we invented the whole sloppy mess of love and intimacy and aversion and euphoria and failure. But most importantly of all, most subversively of all, most stubbornly of all, we invented privacy.

Committed: A Sceptic Makes Peace With Marriage (ed. 2010)