The role of human nature in public policy

Don Herzog writes in the blog, Left2Right:

Today's quiz has just one question. All you have to do is fill in the blank and explain what "unnatural" means. Notice that your account of "unnatural" has to justify the crucial closing clause, "and therefore wrong." I'm happy to make it an open-book quiz, because you'll all fail anyway. Ready? Here goes.

_____________ is unnatural and therefore wrong.

I hasten to note that I am not any kind of skeptic about moral or political argument. My conviction that there is no sound way to fill in the blank here is a targeted skepticism. We have to get along without any appeals to what's natural or unnatural, I think, because those appeals are strictly speaking nonsensical.

That is right, of course. To derive an ought from an is, a moral prescription from a natural description, you’d be committing the naturalistic fallacy, and you’d end up with a non sequitur. So no matter how you fill in that blank, the sentence simply wouldn’t make sense. Herzog points to “gay marriage” and “anal sex” and “abortion” as examples of terms that are filled into that blank and presented as arguments by conservatives.

However, Herzog builds a straw man later in the post when he says:

Worse yet, with confusions piled on confusions, is trying to make just-so stories about evolutionary biology ground moral arguments. We're free to reject the morality of rape or promiscuity even if we think it would pay off in gene pool frequencies.

No evolutionary psychologist that I know of has tried to ground moral arguments in human nature, and Steven Pinker, in fact, constantly warns against drawing such conclusions. And of course we’re “free to reject the morality of rape or promiscuity”; whoever said otherwise?

While human nature should certainly not be the basis of morality, should it play a part in public policy? I believe it should. Instead of Herzog’s test statement, consider the following sentence:

_____________ is unnatural and therefore impractical.

Can the blank here be filled in for the sentence to make sense? I think so. One example: “communal sharing of property”.

Any political system that requires us to behave in a manner contrary to human nature is likely to fail. For example, EO Wilson once said of communism: “great idea, wrong species”. He thought it would have worked for ants, who are wired differently.

Capitalism, on the other hand, is the perfect system for humans because it mirrors the manner of our evolution perfectly. John Maynard Keynes once said of Charles Darwin's The Origin of Species that it was “simply Ricardian economics couched in scientific language”, while Karl Marx wrote to Friedrich Engels that it was “remarkable how Darwin recognizes among beasts and plants his own English society with its division of labor, competition, opening up of new markets, ‘inventions’, and the Malthusian struggle for existence.” Stephen Jay Gould described natural selection as “essentially Adam Smith's economics read into nature.” (These three quotes are from Matt Ridley's fine book, The Origins of Virtue.)

Thus, if public policy is to work, it must take into account human nature and recognise our limits. But that should not become an excuse for justifying immoral acts, such as, to use Herzog's example, rape. As Herzog writes, morality must be determined independent of human nature. Only then should we think of what is practical.

[Link via email from Sanjeev.]