"If we accept that there will always be sides, it's a nontrivial to-do list item to always be on the side of angels. Distrust essentialism. Keep in mind that what seems like rationality is often just rationalization, playing catch-up with subterranean forces that we never suspect. Focus on the larger, shared goals. Practice perspective taking. Individuate, individuate, individuate. Recall the historical lessons of how often the truly malignant Thems keep themselves hidden and make third parties the fall guy. And in the meantime, give the right-of-way to people driving cars with the "Mean people suck" bumper sticker, and remind everyone that we're all in it together against Lord Voldemort and the House Slytherin."