What a dull universe it would be if everything in it conformed to our expectations, if it held nothing to surprise or baffle us or confound our common sense. A century ago no one foresaw the existence of black holes, an expanding universe, oceans on Jupiter's moons, or DNA. What could be more enriching than to know that we share a common origin with all living things, that we are kin to chimpanzees, redwoods and mollusks? And isn't it a source of wonder to realize that the iron in our blood and the calcium in our bones were created in the bellies of supernovas?

In many Muslim countries, witchcraft is not only on the books as a crime, but is commonly prosecuted. In 2009, for example, Saudi Arabia convicted a man for carrying a phone booklet with characters in an alphabet from his native Eritrea, which the police interpreted as occult symbols. He was lashed three hundred times and imprisoned for more than three years.

But the 20th century suffered "two" ideologies that led to genocides. The other one, Marxism, had no use for race, didn't believe in genes and denied that human nature was a meaningful concept. Clearly, it's not an emphasis on genes or evolution that is dangerous. It's the desire to remake humanity by coercive means (eugenics or social engineering) and the belief that humanity advances through a struggle in which superior groups (race or classes) triumph over inferior ones.

We really are creatures of a violent world, biologically speaking - watching violence and learning about it is one of our cognitive drives.

As many political writers have pointed out, commitment to political equality is not an empirical claim that people are clones.

For one thing, before the 20th century, there were plenty of genocides. We tend to forget about them, partly because they weren't as well documented and partly because, until recently, people didn't care. We used euphemisms like 'sackings' and 'sieges' instead of calling them 'genocides.'

If anything, Powerpoint, if used well, would ideally reflect the way we think.