I think a lot of these points come together in Chapter 6, which is called “Animal Intelligence.” The title gives a pretty good sense of what’s in there: scientists trying to figure out how all kinds of non-human animals learn to solve problems and navigate their environments.Aside from the fascinating stories, the chapter will give readers a window onto how far afield these debates about method really got. Because it shouldn’t be obvious that someone studying a rat in a maze is also, at the same time, thinking carefully about the foundations of science. But that’s the story, that’s what they were doing.Working within the framework of Darwin’s theory of evolution by natural selection, the founders of what was called “comparative psychology” at the time were convinced that you could explain even the highest levels of cognition by appealing to an evolutionary process. And if you believe that, then there’s a story to tell connecting the rat in the maze to the scientist studying that rat. Both of them are, in some sense, engaging in an experimental procedure based in trial and error.Of course, there’s a difference between what rats do when they hunt for cheese and what scientists do when they write on their clipboards. A big difference. But the fact that it’s a difference of degree, rather than kind, really mattered to these psychologists.Seeing the roots of your own method “out there” in other animals started to naturalize that method. Comparative psychologists could appeal to this natural history of method as a way to say “See—I’m solving problems in my field the way they’re meant to be solved!”Like I said, there are problems with this approach. Taken too far, it implies that a rat or a kid or a politically motivated skeptic has as much authority as a trained scientist.But we don’t have to take it that far. In the next chapter, on the application of these ideas in schools, we see how this inclusive approach to scientific thinking got translated into a successful curriculum that’s still being used in science education today.However, this approach got shorn of its context. Once it started moving around without the natural history that buttressed it, that’s when we start to see this idea of “the scientific method” emerge as science’s brand, as a way to separate it from society.History has a lot to teach us. We know that. The hard part is making the leap from past to present, or more generally from “is” to “ought.”One way to use history is as a map of paths not taken. I think that’s the most obvious implication of the book: it shows what a generation of scientists thought they were doing by reflecting on method by studying other minds—before their work was taken in a different direction. If we go back to their original vision, we might find some lessons for shoring up expertise today.There are other implications I wish I’d brought out more explicitly in the book. One has to do with politics. The move to naturalize science paved the way for insisting that it was apolitical. This idea has been used (unsuccessfully, in many cases) to shield science from politics.But as I show in Chapter 2, this research program actually began with politics—specifically, with the desire to define science as both radical and conservative. Science, in this view, encompasses politics. If we thought of it that way today, we might have different strategies for building trust in it.The other implication that’s mostly latent in the book has to do with objectivity. Attempting to find a least common denominator for science, something so general you could find it in any animal, these scientists framed it as an objective tool—usable in any context, on any problem.But there’s another way to think about objectivity, one that builds our identities into science, rather than separating them out. Feminist arguments for “Strong Objectivity” or what Donna Haraway has called “situated knowledges,” adopt this view—and it has immense potential for repairing our sense of science as a human activity, as something we do together, fallibly.I’m drawn to this view of objectivity, and I think some of the figures in my book would’ve been too. One of them, William James, was actually the source of my epigraph. I think it makes as much sense as a conclusion as it did as an opening: “Theories thus become instruments, not answers to enigmas, in which we can rest. We don’t lie back upon them, we move forward, and, on occasion, make nature over again by their aid.”