More than anything else, I think this column illustrates the perils of taking a religiously motivated belief and trying to justify it on secular grounds. It just doesn't work. The slippery slope here pretty obviously doesn't amount to much, so you're left with a simple disapproval of people deciding to take their own lives. And what's the argument for that? Douthat doesn't provide one. He simply declares it murder and calls it a day. Without recourse to his underlying religious objections, that's really his only choice.