Terrorist bombings, like rampage shootings, are events that maximize the amount of publicity per amount of damage. That's why people do them, because they know they will set off a media frenzy.

All over the world, belief in the supernatural has authorised the sacrifice of people to propitiate bloodthirsty gods, and the murder of witches for their malevolent powers.

Commerce, trade and exchange make other people more valuable alive than dead, and mean that people try to anticipate what the other guy needs and wants. It engages the mechanisms of reciprocal altruism, as the evolutionary biologists call it, as opposed to raw dominance.

There has to be innate circuitry that does the learning, that creates the culture, that acquires the culture, and that responds to socialization.

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

As every student in Philosophy 101 learns, nothing can force me to believe that anyone except me is conscious. This power to deny that other people have feelings is not just an academic exercise but an all-too-common vice, as we see in the long history of human cruelty.

Solving a problem in a hundred years is, practically speaking, the same as not solving it at all.