Rationality: What It Is, Why It Seems Scarce, Why It Matters

By Steven Pinker (Allen Lane, £25)

Steven Pinker has written a sensible book for our senseless times—a post-lockdown wake-up call whose overflowing optimism in the end rings hollow. His targets are what he calls the “cockamamies” and “doozies” of our era—a very mixed bag of conspiracy theorists, anti-vaxxers, Trump supporters and people blind to the benefits of taking out a pension. It is they who have prompted this further addition to Pinker’s growing number of books celebrating the light of reason. (His last book was called Enlightenment Now.) His favourite arguments are reiterated: progress is real, wealth is a man-made miracle and, despite the irrationality we see around us, Enlightenment values always win in the end.

What’s new? This time we get a more detailed definition of rationality as “goal-oriented reasoning.” Like Socrates, Pinker notes that no one seeks to harm themselves willingly. Unlike Socrates, Pinker has solutions to avoid self-inflicted woes: do not take coincidences for necessary causes; refrain from being impressed by big numbers that are actually hiding the most important data; and, when making life choices, multiply your desired outcome by its probability and compare the result with your ultimate goal. Et voilà!

Philosophers play little role in Pinker’s book. His is the scientist’s world of calculation and quantified chances: simple maths gets the odds on your side. There is no room for conscience, ideals or empathy—those are mere covers for biases, group-signalling or self-indulgence, so he claims. Perhaps this is the most striking aspect of the book: its array of puzzles, thought experiments and bias-scouting quizzes is divorced from the ancient caution that the unexamined life is not worth living. It sometimes feels like Pinker would have voted to execute Socrates for the sake of commonsense progress.

Pinker allows us a margin of superiority over robots. But tellingly, he calls humans a “hybrid system”—a rather robotic phrase. His offer of membership to his “Rationalists’ Club” is not especially tempting. Groucho Marx—o en quoted by Pinker—had a famous line about that: “I refuse to join any club that would have me as a member.”