Steven Pinker should stick with linguistics

MIT linguist Steven Pinker recently wrote a piece in the New Republic entitled Science Is Not Your Enemy: An impassioned plea to neglected novelists, embattled professors, and tenure-less historians, in which he argues not only that the scientific method can enhance our understanding of the humanities, but that scientific facts should serve as the basis for all human morality. Pinker writes:

[T]he worldview that guides the moral and spiritual values of an educated person today is the worldview given to us by science. Though the scientific facts do not by themselves dictate values, they certainly hem in the possibilities. By stripping ecclesiastical authority of its credibility on factual matters, they cast doubt on its claims to certitude in matters of morality. ... And in combination with a few unexceptionable convictions — that all of us value our own welfare and that we are social beings who impinge on each other and can negotiate codes of conduct — the scientific facts militate toward a defensible morality, namely adhering to principles that maximize the flourishing of humans and other sentient beings. This humanism, which is inextricable from a scientific understanding of the world, is becoming the de facto morality of modern democracies, international organizations, and liberalizing religions, and its unfulfilled promises define the moral imperatives we face today.[emphasis added]

Pinker, whose writings on linguistics and cognitive science I have found very enlightening over the years, here appears to be completely unacquainted with world history over the last several centuries. Does Pinker have any idea how dangerous that phrase "the scientific facts militate toward a defensible morality" is? The Jacobins of the French Revolution, the Bolsheviks of the Russian Revolution, and the Maoists in China were well acquainted with this kind of thinking: they, too, were convinced that the "scientific facts" as they understood them "militated towards a defensible morality." They ended up almost "militating" their nations out of existence.

Furthermore, how are we to implement the "maximization of the flourishing of humans and other sentient beings?" Cows, for example, are sentient beings. How is an effort to maximize the flourishing of cows consistent with the fact that we slaughter them every day for our consumption? What's more, if, on the one hand, we can justify the slaughter of cows for the sake of maximizing the flourishing of a larger group of sentient beings (thankfully, including us humans), and yet, on the other hand, science cannot distinguish between the worth of a cow and the worth of a human being (after all, as Pinker says, "scientific facts do not by themselves dictate values"), then, what is to prevent society from slaughtering the occasional human if it can be shown based on "scientific facts" that his death will maximize the flourishing of all the other humans and sentient beings in aggregate. In fact, this was precisely the logic that Lenin and Mao applied: certain segments of the Russian and Chinese nations had to be sacrificed to promote the general welfare of the Proletariat. Pinker does allow for the "unexceptionable conviction that all of us value our own welfare," but, exactly how he proposes to pursue the one principle of maximizing the welfare of all while preserving the welfare of the individual, he does not venture to say.

Steven, better stick with linguistics.