The foreign gaze

Reflecting on the so-called "savages" of the New World, Montaigne noticed that "each man calls barbarism whatever is not his own custom" (Of Cannibals). Before you let your reflex of disgust pass for a moral verdict, turn the gaze around: ask how your own customs would look to that other eye. The point is to tell a real wrong from mere unfamiliarity, so that "it's not how we do it" stops counting as "it's wrong".