Joshua Rothman does a review of a new book by Michael Strevens, a philosopher at New York University,"The Knowledge Machine: How Irrationality Created Modern Science". Strevens, noting that science is objective while scientists are not, asks whether an "iron rule" can explain how they changed the world anyway. I'm passing on some central points with a few clips of text, and suggest you read the whole review, which describes the contexts of several scientific breakthroughs.
In school, one learns about “the scientific method”—usually a straightforward set of steps, along the lnes of “ask a question, propose a hypothesis, perform an experiment, analyze the results.” ....Two twentieth-century philosophers of science, Karl Popper and Thomas Kuhn, are widely held to have offered the best accounts of this process. Popper maintained that scientists proceed by “falsifying” scientific claims—by trying to prove theories wrong. Kuhn, on the other hand, believed that scientists work to prove theories right, exploring and extending them until further progress becomes impossible. These two accounts rest on divergent visions of the scientific temperament. For Popper, Strevens writes, “scientific inquiry is essentially a process of disproof, and scientists are the disprovers, the debunkers, the destroyers.” Kuhn’s scientists, by contrast, are faddish true believers who promulgate received wisdom until they are forced to attempt a “paradigm shift”—a painful rethinking of their basic assumptions.
The allocation of vast human resources to the measurement of possibly inconsequential minutiae is what makes science truly unprecedented in history. Why do scientists agree to this scheme? Why do some of the world’s most intelligent people sign on for a lifetime of pipetting?
Strevens thinks that they do it because they have no choice. They are constrained by a central regulation that governs science, which he calls the “iron rule of explanation.” The rule is simple: it tells scientists that, “if they are to participate in the scientific enterprise, they must uncover or generate new evidence to argue with”; from there, they must “conduct all disputes with reference to empirical evidence alone.” Compared with the theories proposed by Popper and Kuhn, Strevens’s rule can feel obvious and underpowered. That’s because it isn’t intellectual but procedural. “The iron rule is focused not on what scientists think,” he writes, “but on what arguments they can make in their official communications.” Still, he maintains, it is “the key to science’s success,” because it “channels hope, anger, envy, ambition, resentment—all the fires fuming in the human heart—to one end: the production of empirical evidence.”
Strevens arrives at the idea of the iron rule in a Popperian way: by disproving the other theories about how scientific knowledge is created. The problem isn’t that Popper and Kuhn are completely wrong. It’s that scientists, as a group, don’t pursue any single intellectual strategy consistently. Exploring a number of case studies—including the controversies over continental drift, spontaneous generation, and the theory of relativity—Strevens shows scientists exerting themselves intellectually in a variety of ways, as smart, ambitious people usually do. Sometimes they seek to falsify theories, sometimes to prove them; sometimes they’re informed by preëxisting or contextual views, and at other times they try to rule narrowly, based on the evidence at hand.
Why did the iron rule emerge when it did? Strevens takes us back to the Thirty Years’ War, which concluded with the Peace of Westphalia, in 1648. The war weakened religious loyalties and strengthened national ones...As Isaac Newton wrote, “The laws of God & the laws of man are to be kept distinct.” These new, “nonoverlapping spheres of obligation,” Strevens argues, were what made it possible to imagine the iron rule. The rule simply proposed the creation of a third sphere: in addition to God and state, there would now be science.
The iron rule—“a kind of speech code”—simply created a new way of communicating, and it’s this new way of communicating that created science. The subjectivists are right, he admits, inasmuch as scientists are regular people with a “need to win” and a “determination to come out on top.” But they are wrong to think that subjectivity compromises the scientific enterprise. On the contrary, once subjectivity is channelled by the iron rule, it becomes a vital component of the knowledge machine. It’s this redirected subjectivity—to come out on top, you must follow the iron rule!—that solves science’s “problem of motivation,” giving scientists no choice but “to pursue a single experiment relentlessly, to the last measurable digit, when that digit might be quite meaningless.”