disappearance. (The statement “x > y” is different from the statement “y = 0.”) Something can decrease a lot without vanishing altogether. That means that the level of violence today is completely irrelevant to the question of whether violence has declined over the course of history. The only way to answer that question is to compare the level of violence now with the level of violence in the past. And whenever you look at the level of violence in the past, you find a lot of it, even if it isn’t as fresh in memory as the morning’s headlines.
