In this talk at the Tri-State Conference for Heads of School at the Mohonk Mountain House, Timothy Snyder discusses his new book, "On Tyranny." “The Founding Fathers tried to protect us from the threat they knew, the tyranny that overcame ancient democracy. Today, our political order faces new threats, not unlike the totalitarianism of the twentieth century. We are no wiser than the Europeans who saw democracy yield to fascism, Nazism, or communism. Our one advantage is that we might learn from their experience.”