Is It Insane To Kill?

The great French writer, Albert Camus, once said to live in the first half of the  twentieth century was to become aware of  every form of human horror. German people killed over 30 million of their fellow Europeans. Over in China, Mao tse-tung killed over 20 million of his fellow Chinese. Name any country and one can find evidence of  murder and mayhem. Of course, those who murder under guise of State argue that God or a voice or the object of  murder is the cause of their being killed. We humans murder in the name of something or someone.

Anders Behring Breivik, a young Norwegian man, went on a  murderous spree last year. He calmly murdered 69 young people at a summer camp and was rather pleased with his actions. He also killed others in Oslo. A team of psychiatrists concluded that he was legally insane. They claim he suffers from paranoid schizophrenia. I have no doubt their conclusion is correct.

However, how do we humans explain mass murder which has gone on and still goes on this planet? Are all these murderers suffering from paranoid  schizophrenia?