In the 1970s, many intellectuals had become political radicals. Marxism was correct, liberalism was for wimps, and Marx had pronounced that 'the ruling ideas of each age have ever been the ideas of its ruling class.'

One of the perks of being a psychologist is access to tools that allow you to carry out the injunction to know thyself.

If we are not to abandon values such as peace and equality, or our commitments to science and truth, then we must pry these values away from claims about our psychological makeup that are vulnerable to being proven false.

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

It is true that raids and battles killed a tiny percentage of the numbers that die in modern warfare. But in tribal violence, the clashes are more frequent, the percentage of men in the population who fight is greater, and the rates of death per battle are higher.

Equality is not the empirical claim that all groups of humans are interchangeable; it is the moral principle that individuals should not be judged or constrained by the average properties of their group.

The doctrine of the sacredness of the soul sounds vaguely uplifting, but in fact is highly malignant. It discounts life on earth as just a temporary phase that people pass through, indeed, an infinitesimal fraction of their existence…the gradual replacement of lives for souls as the locus of moral value was helped along by the ascendency of skepticism and reason