Scholars Sherif Girgis, Robert George, and Ryan Anderson have a lengthy new paper on the question, to which NYU’s Kenji Yoshino responds here, proclaiming that the “best argument against gay marriage” has failed. I haven’t had time to sit down with the original piece, but I have read Yoshino’s response, as well as the trio’s counter-response. Judging from them, “What Is Marriage?” and its follow-ups seem like required reading, no matter where you stand on gay marriage. (Hat tip: American Power)