Leaders and people in power have always had to ask a big question. "How do I make sure everyone obeys me?" For hundreds of years there was one answer. Pain. Or the threat of pain. History was full of the screams of criminals and others. They were made to suffer for doing wrong - or thinking the wrong things. But many laws were different then. You could be put to death for crimes that do not seem serious today. And many of the screams came from people who had done no wrong at all.