Oddly Influenced

Welcome to oddly influenced, a podcast about how people have applied ideas from *outside* software *to* software. A mini-episode: Galison doubts Kuhn’s idea of scientific revolutions

To be awkward for a moment: two impending deaths in our family, a thousand miles apart, have left me simultaneously wanting to get my mind off things by doing work, but also having difficulty making a longer, coherent episode. So what I’m going to do is publish a few short episodes about topics in Galison’s /Image and Logic/ that might be useful – or at least interesting – to you.

This episode is the least “actionable”. It’s about Thomas Kuhn’s 1962 book /The Structure of Scientific Revolutions/. That book has been enormously influential. If you’ve read only one one book on the history or philosophy of science, it was probably Kuhn’s. Galison, however, argues that Kuhn’s book was wrong because he, Kuhn, suffered from a crucial blindspot.

Kuhn’s book marked what some called the “psychologizing” of science. That is, his critics say he made scientific progress come down to little more than individual psychology. That’s in contrast to earlier philosophies of science that were all about the underlying, foundational *logic* of scientific progress, a logic disconnected from the human beings who carry it out.

Kuhn argues as follows:

1. Science progresses in periods of *normal science* punctuated by periods of confusion, chaos, and revolution.

2. Normal science consists of working out the consequences of settled theory, what Kuhn calls a “paradigm”.That’s the kind of science my wife used to do. She once published a paper comparing the composition of cow, goat, sheep, llama, and human milk. (If you want to start out a business selling high-end infant formula, you’ll want to know that llama milk is closest to human milk.) Kuhn compares normal science to solving puzzles, which makes sense to me. For example, it turns out llamas are really hard to milk, even for baby llamas.

3. As more and more normal science is done, Kuhn says anomalies, oddities, and contradictions pile up. Most scientists take them in their stride, but some at some point decide that the paradigm is in crisis. They take it upon themselves to invent a new paradigm by questioning and replacing long-held assumptions.

4. If they succeed, you now have two competing paradigms. If the new one fails, and sometimes they do, scientists keep doing normal science. If it succeeds, it replaces the old one, and scientists start doing normal science that fits the new paradigm. There’s been a “paradigm shift”. Yes, every time you hear a marketing person or a venture capitalist say “paradigm shift”, you have Kuhn to blame.

The question now is what determines whether a revolution succeeds or fails?

Kuhn’s controversial point is that it doesn’t happen by scientists comparing the two paradigms. He says paradigms are *incommensurable*, literally not comparable. People in a new paradigm mean different things by shared words. For example, “mass” means a different thing to Einstein than it did to Newton. A new paradigm has new rules for what questions are worth asking – or what questions even make sense. And it has different standards of evidence. Paradigms are different worldviews, and Kuhn says it’s simply impossible to meaningfully talk between them. An analogy Kuhn uses is that picture that sometimes looks like a duck and sometimes like a rabbit. His point is that you cannot simultaneously see the picture as both. At any moment, you’re inherently committed to one and can’t even *see* – or really conceive of – the other.

So how do scientists choose whether to stick with the old paradigm or adopt a new one? For any reason they want! Like Lakatos said in episode 7, the new paradigm will initially explain less than the old one, and it will start out in, quote “a sea of anomalies”. Kuhn says the savvy scientist will want to *believe* that the new paradigm will *eventually* be able to explain most everything the old one did, and more besides, but the reasons scientists switch are individual. They might just be bored with doing normal science and want an adventure. Or they’re young and see the current chaos as an opportunity for a big bet with a big reward, better than waiting for old scientists to die and get out of the way.

Once enough scientists switch, the textbooks get rewritten and the non-revolutionaries like my wife settle down to doing their normal science under the new paradigm.

Galison says Kuhn is historically inaccurate because he, Kuhn, like his predecessors, focused on theory to the exclusion of experiment. In old-style history and philosophy of science, theorists are the bosses. Experimenters do as they’re told. So Kuhn assumes that if theorists are having a paradigm shift, the experimenters get swept along by the chaos. Galison says Kuhn is wrong.

Quote

“The practice of experimental physics in the quantum mechanical revolution of 1926-27 was not violently dislocated despite the startling realignment of theory: spectroscopy continued unabated, as did measurements of specific heat and blackbody radiation. And practitioners of these experimental arts continued undaunted their dialogue with theorists on both sides of the great theoretical divide. Each subculture has its own rhythms of change, each has its own standards of demonstration, and each is embedded differently in the wider culture of institutions, practices, inventions, and ideas.”

Key to Galison’s take is that theorists and experimenters were *always* dealing with the difficulties that Kuhn claims only come up during paradigm shifts: they always had disagreements about what terms mean, what counts as evidence, and so on. They worked around that by creating the trading zone to focus on common procedures and restricted meanings.

Galison thinks this process – of one subculture continuing on unruffled while another is in uproar – is key to the success of science. Quote: “science is disunified and – against our first intuitions – it is precisely the disunification of science that brings strength and stability.” Or, quote: “Behind the felt coherence, continuity, and strength of physics lies immense heterogeneity: [and] coordination of subcultures.”

I hate to be all politically correct, or woke, or whatever the preferred insult is today, but: there is strength in diversity, if you can figure out how to manage it. Galison compares physics to a laminated piece of wood: if one layer breaks, the other layers can still hold the whole thing together.

Why is the throw-down between Galison and Kuhn important?

You’ve probably noticed that I draw a lot of inspiration from books about the history and philosophy of science. That’s because they address a really important issue: *something* changed around the 1600s about how humans understand and control nature. Science and engineering sure *seem* to progress at a faster pace than, say, political theory and practice, international relations, or philosophy. So what’s going on?

After around 40 years of reading such books, I can say with confidence that: it’s complicated.

To the extent that we in software want to model ourselves after science – which I think a lot of us do – it’s important that we understand that the history of science doesn’t give us simple and obvious answers.

Thank you for listening.