Does Atheism Cause Slaughter?

Steve Pinker, in “The Better Angels of our Nature: Why Violence Has Declined”, has done a great deal of research about violence throughout history. Recently, he posted this on his website in answer to the common theistic assertion that atheism is the cause of the atrocities committed during the 20th century.

“This is a popular argument among theoconservatives and critics of the new atheism, but for many reasons it is historically inaccurate.
First, the premise that Nazism and Communism were “atheist” ideologies makes sense only within a religiocentric worldview that divides political systems into those that are based on Judaeo-Christian ideology and those that are not. In fact, 20th-century totalitarian movements were no more defined by a rejection of Judaeo-Christianity than they were defined by a rejection of astrology, alchemy, Confucianism, Scientology, or any of hundreds of other belief systems. They were based on the ideas of Hitler and Marx, not David Hume and Bertrand Russell, and the horrors they inflicted are no more a vindication of Judeao-Christianity than they are of astrology or alchemy or Scientology.
Second, Nazism and Fascism were not atheistic in the first place. Hitler thought he was carrying out a divine plan. Nazism received extensive support from many German churches, and no opposition from the Vatican. Fascism happily coexisted with Catholicism in Spain, Italy, Portugal, and Croatia. See p. 677 for discussion and references.
Third, according to the most recent compendium of history’s worst atrocities, Matthew White’s Great Big Book of Horrible Things (Norton, 2011), religions have been responsible for 13 of the 100 worst mass killings in history, resulting in 47 million deaths. Communism has been responsible for 6 mass killings and 67 million deaths. If defenders of religion want to crow, “We were only responsible for 47 million murders—Communism was worse!”, they are welcome to do so, but it is not an impressive argument.
Fourth, many religious massacres took place in centuries in which the world’s population was far smaller. Crusaders, for example, killed 1 million people in world of 400 million, for a genocide rate that exceeds that of the Nazi Holocaust. The death toll from thehirty Years War was proportionally double that of World War I and in the range of World War II in Europe (p. 142).
When it comes to the history of violence, the significant distinction is not one between thesistic and atheistic regimes. It’s the one between regimes that were based on demonizing, utopian ideologies (including Marxism, Nazism, and militant religions) and secular liberal democracies that are based on the ideal of human rights. On pp. 337–338 I present data from Rummel showing that democracies are vastly less murderous than alternatives forms of government.”

What more can be said, except that the argument was irrelevant to begin with. The question is not whether religion makes people behave nicely, but whether it constitutes an accurate view of the world. If it does, then there ought to be some way to demonstrate this fact. If it doesn’t, then since we invented religion, we can invent whatever we need to replace it.
I’m not taking sides here guys, it’s just a simple matter of logic, and if God exists, he he gave us brains. If your argument stinks, don’t expect anyone to accept it.