Anyone who has not done so already must, repeat MUST -- read this speech by Stephen Pinker at the American Enterprise Institute. (Link via OxBlog.)

Read the whole thing, as they say. But here; have dessert first:

....[A]s soon as one is dependent on the behavior of other people, it is incoherent to insist that they follow a code of behavior that one is not willing to follow oneself simply because there is nothing privileged about one person's position in the universe compared to anyone else's. And it's this notion of the interchangeability of perspectives or the interchangeability of interests that really lies at the heart of moral systems, such as the Golden Rule, the categorical imperative, and others.

So, to sum up, I've argued that the dominant theory of human nature in modern intellectual life has been based on the blank slate, the noble savage, and the ghost in the machine. These ideas are being challenged by the modern sciences of mind, brain, genes, and evolution. These challenges have also been seen to threaten important moral values, but, in fact, that doesn't follow.

On the contrary, I think a better understanding of what makes us tick and of our place in nature can clarify those values by showing that political equality does not require sameness but, rather, policies that treat people as individuals with rights; that moral progress does not require that the mind is free of selfish motives, only that it has other motives to counteract them; that responsibility does not require that behavior is uncaused, only that it responds to contingencies of credit and blame; and that meaning in life does not require that the process that shapes the brain have a purpose, only that the brain itself have a purpose.

Finally, I've argued that grounding values in a blank slate is a mistake. It's a mistake because it makes our values hostages to forfeit, implying that someday empirical discoveries could make them obsolete. And it's a mistake because it conceals the downsides of denying human nature, including persecution of the successful; totalitarian social engineering; an exaggeration of the effects of the environment, such as in parenting and the criminal justice system; a mystification of the bases of responsibility, democracy, and morality; and the devaluating of human life on Earth.