What does a 900-year-old crusader sword discovered underwater by divers have in common with a rape on a Philadelphia commuter train last week? They both point to the fact that human nature hasn’t changed much, if at all, in the past millennia. Divers made the exciting discovery of a weapon dating to the Third Crusade in 13 feet of water. It’s easy for us to imagine a time when everybody had to be their own police force, body guard, and army combined. If you didn’t carry a weapon, you couldn’t defend yourself. If you didn’t defend yourself, there was no guarantee anybody else would. In those days you didn’t just call grab your cell phone and call 911.