At a time when belief in science appears to be waning, conspiracy theories seem to be on the rise, and many Americans cannot agree on basic facts, Steven Pinker argues for a return to rational thought and public discourse in his latest book, “Rationality: What It Is, Why It Seems Scarce, Why It Matters.” Pinker, Harvard’s Johnstone Family Professor of Psychology, and author of “The Better Angels of Our Nature,” and “Enlightenment Now,” thinks “we will always need to push back against our own irrationality,” and that education, democracy, science, and journalism, along with an awareness of our own biases, can help us embrace a more rational approach to everyday issues. The interview was edited for clarity and length.
GAZETTE: Can you define rationality in a sentence?
PINKER: I define it as the use of knowledge to attain a goal, where “knowledge,” according to the standard philosopher’s definition, is “justified true belief.”
GAZETTE: We see examples of seemingly irrational beliefs and behaviors every day, but you argue that people are fully capable of being rational. How do you explain that disconnect?
PINKER: First, rationality is always in pursuit of a goal. Sometimes that goal is rational for each of us as individuals but irrational for us as a society — a tragedy of the rationality commons, as when it makes sense for every shepherd to graze his sheep on the town commons, but when everyone does it, the commons gets denuded and they’re all worse off. In this case, if everyone is ingenious in gaining prestige within their political sect by glorifying its sacred beliefs and demonizing rival sects, that may work to everyone’s individual advantage, but not to the advantage of the whole society in its interest in the truth and the best policies.
Another part of the answer is that we are born with primitive intuitions that served us well in traditional societies but have become obsolete in a scientifically sophisticated one. For example, we have the intuition that living things harbor an essence, an inner stuff that makes them function and gives them their powers, and that disease comes from external contaminants that pollute it. That leads us to quack remedies like bloodletting, purging, cupping, and homeopathy, and opposition to genetically modified foods. Likewise, the intuition of dualism, that people have minds as well as bodies, leads naturally to a belief in minds without bodies, so we have ghosts and ESP and communicating with the dead. The intuition of design in our plans and artifacts leads to creationism and the superstition that “everything happens for a reason.”
Now most of us unlearn these intuitions when we buy into the consensus of the scientific establishment — it’s not as if we understand the physiology or neuroscience or cosmology ourselves. But many people don’t trust the scientific establishment, so they fall back on those intuitions.
Finally, the conviction that all our beliefs should be grounded in evidence is psychologically unnatural. I quote Bertrand Russell, “It’s undesirable to believe a proposition when there’s no ground whatsoever for supposing it is true.” But that’s not a truism: it’s a radical manifesto. Most of us insist on reality when it comes to our immediate surroundings and our everyday lives. We have no choice: It’s the only way to get the kids clothed and fed, to keep gas in the car and food in the fridge. But we may not care about literal factuality when it comes to distant and cosmic questions like: How did life arise? What happens in remote halls of power? What’s the ultimate cause of disease? Until there was modern science and record-keeping and journalism, we had no way of finding out the answers anyway. Mythology was the best we could do, and the criteria were uplift and solidarity and entertainment, not literal truth.