Note: This post concludes our review of Tyler Cowen’s new book “Stubborn Attachments.”
Although we have expressed deep skepticism about moral discourse (especially utilitarian or consequentialist theories of ethics), we have also taken the position that if we must talk about moral duties towards future generations, we should replace population utilitarianism with an intertemporal golden rule. To sum up our argument thus far, the golden rule combines the best elements of Kantian reasoning (universality) with Humean logic (mutual self-interest). In fact, when it is stripped down to its essential elements, the golden rule can be reformulated in terms of “reciprocal altruism,” a pattern of behavior initially described by Robert Trivers (one of our intellectual heroes) in which an actor (the benefactor) confers benefits on another actor (the recipient) with the expectation that the recipient will repay the benefactor’s generosity in the future. Or in plain English: you scratch my back, and I’ll scratch yours.
But what about our intertemporal golden rule? Can reciprocal altruism work across generations? In our view, the answer is, “It depends.” Specifically, the viability of any form of intertemporal reciprocal altruism will depend on our implicit degree of belief that future generations will also act in the best interests of yet more distant generations. That is, instead of paying us back — a physical impossibility, since we won’t be around in the distant future — we act as if future generations will “pay it forward”! Stated this way, our approach to population ethics resembles the theory of indirect reciprocity in evolutionary biology. (See image below.) There exists an entire body of literature on indirect reciprocity (see here, for example), beginning with Richard D. Alexander’s classic book “The Biology of Moral Systems,” which was first published in 1987, so our idea can’t be too far-fetched. In any case, now that we have laid out our theory of intertemporal reciprocity (i.e. our intertemporal golden rule), we hope that Tyler Cowen and others will one day reconsider their utilitarian approach to population ethics. In the meantime, you should definitely read “Stubborn Attachments” for yourself, for this book is well written and is full of beautiful insights; then be sure to tell us what you think.