I’ve been a big fan of Bruno Latour for a long time now. He started off working in sociology of science, with some very insightful observations of scientists in action, of how science is actually produced and how scientific facts become accepted. Which is not quite the way it is presented by many scientists (or epistemologists); a decade ago, Latour made a foray into philosophy with his book We Have Never Been Modern, to talk about this disconnect. For me, that book was both fascinating and frustrating: Latour did a good job at pointing out some of the absurdities that you see in a certain form of mysticism of Science that was depressingly prevalent around the Sokal affair, and he clearly had some good ideas about a better way to approach epistemology, but those ideas hadn’t yet gelled into a coherent picture.

With his latest book, Politics of Nature, however, he’s finally put it all together. His basic complaint is that mythologists of Science buy into a version of the allegory of the Cave, with an eternal world (Nature, in the case of Science) out there that humans can’t perceive directly. But scientists are supposed to have a unique ability to transcend the social world, producing eternal truths about Nature that nobody is permitted to question, that have no analogue anywhere in the social world. And there’s no clear explanation how, if Nature and the world of the Cave (the social world) are so fundamentally different, how scientists manage to have a unique insight into Nature, giving them a special access to eternal truths that the rest of us can’t manage.

Latour’s explanation is that the (quite valuable!) work that actual scientists do is rather more prosaic and complicated than this mythical picture. Scientists don’t go from direct perception of nature to direct perception of unquestionable truths (and, to be sure, nobody claims that they do this: some form of scientific method is always presented as an intermediate step). Latour proposes analyzing this process through the following four steps:

  1. The requirement of perplexity. An investigation must consider the evidence that appears, no matter how surprising or unpleasant it might seem.
  2. The requirement of consultation. Propositions can’t be considered in isolation: they have to be examined by an appropriately constituted jury.
  3. The requirement of hierarchy. You can’t just accept a proposition as true by itself: it has to fit together with other propositions that you wish to consider true.
  4. The requirement of institution. Once a proposition has been appropriately placed in a hierarchy, it should be accepted, rather than constantly challenged.

The requirements of perplexity and institution are most similar to the naive version of nature and scientific laws: the requirement of perplexity is where we see nature making its presence known (if you jump out of a third-story window, you will fall down, whether you like it or not), and the requirement of institution is where scientific laws get accepted as truth. The journey from the first requirement to the fourth, however, is a quite interesting one.

The second requirement, in particular, is more subtle than it might seem. Latour’s juries aren’t made entirely (or even largely) out of humans: this isn’t some sort of simple peer review, where scientists read each other’s papers and decide whether or not they agree with the results. Instead, members of the jury can be nonhumans (and in particular can be propositions, a term which Latour uses in a quite general sense): so some of the most important members of the jury that is consulted with respect to a candidate proposition consist of measurements that are made that support (or don’t!) the proposition in question. In fact, arguably the greatest strength of science, and the reasons why scientists are much better at coming up with durable propositions than the rest of us, is the remarkable ability that scientists have to assemble a huge jury of nonhumans to pass judgment on a candidate proposition.

Another point of Latour’s is that this process isn’t a one-time thing: when one round of perplexity/consultation/hierarchy/institution has concluded, it opens itself to another round of the same process. So, for example, when a scientific theory becomes accepted, it might cause scientists to be perplexed by facts that they hadn’t noticed before. And the newly instituted facts might enable scientists to build new measuring devices, increasing the size of the juries that they can bring to bear in later consultations. So hierarchies of scientific theories grow and grow through repetitions of this cycle. Also, while propositions that are instituted at the end of one cycle usually remain instituted at the end of the next cycle, that’s not always the case: they may end up being refined, having their scope limited, or even being outright rejected at the end of subsequent iterations.

There’s nothing surprising about this analysis, of course; it’s a reasonably level-headed description of how scientists work, with a somewhat idiosyncratic choice of language and focus. (He uses many words in a somewhat specialized fashion; fortunately, he flags these words with asterisks in the text, and provides a glossary at the back, so it’s usually clear enough what he means.) Its real strength, however, is that there’s nothing about this four-stage analysis that is at all specific to science. In fact, he shows how various professions (politicians, economists, moralists, etc.) can fit their work quite naturally into this framework. So it gets us nicely past any sort of mysticism of Nature and Science: if you want to focus on facts that manage to perplex in a certain especially potent fashion, or on facts that are instituted in a particularly durable way, you’re welcome to do so (and it may even be useful to do so), but there’s no particular benefit in turning that into a transcendent distinction.

I’ve actually started looking at all sorts of aspects of my life through this lens. For example, the problems that I have with the school closure process can largely be traced to problems with the board and administration’s perplexity and consultation: they’re picking and choosing between facts, ignoring the ones they don’t like instead of being properly perplexed by them, and they’re not constituting appropriate juries (both human and otherwise) to review their propositions. Another example is in software development: the software development strategies that I prefer these days can be viewed as focusing on increasing the size of various relevant juries (providing automated tests to verify that your code does what it’s supposed to do, bringing in more voices to help you decide which features to add to your software, which not to add, and how best to implement them) and on increasing the rate at which the entire process cycles through, allowing you to institute propositions (i.e. release software) much more quickly, building up a large hierarchy of propositions (working, stable software fulfilling a well-chosen set of feature requests, doing so in a maintainable and extensible fashion).

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