Yesterday, the American Naturalist Society’s Twitter account (@ASNAmNat) retweeted a question posed by @DanielBolnick:
Can anyone recommend a good reading to teach intro evolution grad students about philosophy of science as it pertains to doing research ?
— Daniel Bolnick (@DanielBolnick) July 11, 2015
This is even a bit tougher request than, for example, a single reading introducing evolutionary biology or genetics. Philosophy of science is less unified than those disciplines. There aren’t many core consensus ideas for beginners to learn, such that only more advanced students are gradually exposed to the more complex and contentious ideas.
One idea
Nonetheless, Bryan Roberts (@SoulPhysics) tweeted a pretty good suggestion: Samir Okasha’s Philosophy of Science: A Very Short Introduction from Oxford’s Very Short Introduction series.
Okasha’s introductory book is very good. But I think it’s non-ideal for serving as a single reading in a science course for students who won’t otherwise be exposed to Philosophy of Science. Trivially, at 134 pages, it’s not actually “Very Short.” I suspect it would push up against graduate students’ one-night attention spans. More significantly, it does something different than what I suggest an ideal single reading might do: it surveys the history of science, the history of Philosophy of Science, and a series of positions and debates and arguments at various levels of abstraction from science itself.
What’s left? Puzzles. I’d suggest that a good goal for quickly exposing science students to Philosophy of Science is to persuade them that genuinely compelling philosophical puzzles appear in the science they already know and in the reasoning behind it. Many science students reading or hearing about Philosophy of Science for the first time are skeptical that there could be anything to it, that it could amount to anything more than speculative blather dancing around the periphery of the established scientific facts. I want to persuade them otherwise, cultivate their eye for recognizing philosophical problems in their own work and disciplines, and ideally communicate that a large literature on such problems exists. Most of all, I want them to go from zero to “Hmmm, wow, I don’t know, and I would have thought I did,” as quickly as possible.
I don’t mean that Okasha fails to present questions, problems, and open debates. I mean that in that short book he favors a more systematic presentation over foregrounding particular puzzling problems and what makes them difficult and exciting.
My suggestion
The problem I suggest for the Evolution class is “What is the principle of natural selection, and what does it say?” But don’t start with that question! Stated on its own, it is not a compelling question for most students. So let’s get there in two readings.
First reading: Carl Hempel, Philosophy of Natural Science (1966), pages 47–58 in the chapter “Laws and Their Role in Scientific Explanation.” (Worldcat link) Hempel argues that laws are an essential part of scientific theories, in that only they can ground explanatory understanding. Pump students’ intuitions by discussing Newton’s laws and the Ideal Gas Law. Newton’s achievement was identifying several laws that work together to explain extremely diverse phenomena. Hempel argues that such laws must be true, universal generalizations.
Second reading: John Beatty, “The Evolutionary Contingency Thesis,” in Concepts, Theories, and Rationality in the Biological Sciences (1995), ed. by Gereon Wolters and James G. Lennox, pages 45–81. University of Pittsburgh Press. (Here’s the Worldcat listing for the book, and a digital copy from Pittsburgh Press.) Beatty argues in an accessible way that since biological organisms have evolved in contingent ways, any distinctly biological law-like generalizations must be contingent on that evolutionary history, rather than universally true. Consequently, evolutionary biology has no laws of its own.
I think students reading those two pieces should start to be puzzled about at least some of the following questions:
What is the principle of natural selection? Can it be expressed a law, like one of Newton’s laws? If we try to express it as a law, is the statement true? Is natural selection instead a historical process, or a mechanism, or a metaphor characterizing a certain model of organic change, or what? Does biology have laws other than a principle of natural selection? Does evolutionary biology make predictions? Must scientific theories be capable of making predictions? What makes evolutionary theory a scientific theory if it fails to have a law at its core? What counts as an explanation in evolutionary biology, if not logical deduction from laws and circumstances? What’s the relationship between the theory of evolutionary biology and the theories in Chemistry and Physics? And more specifically, is Gould right that evolution could have played out differently, in nearly infinite ways? In what sense are some other possibilities possible?
Students or instructors can zero in on the specific questions they find most puzzling. This pair of readings raises other questions. There are a lot of them. I think if students find themselves genuinely puzzled by any of these questions—experiencing doubt about how to answer them combined with a sense that the questions should have answers—the assignment succeeds. Its success lies not in creating confusion, but in creating puzzlement. Puzzlement includes the recognition that clarity about possible answers is possible—some of which possible answers have been offered by the two philosophers they’ve read.
Of course, puzzlement is not an end in itself. Here it’s a key to understanding (by means of experiencing) that there are substantive questions that can’t be resolved empirically, which is to say substantive philosophical questions. There are certainly other readings and pairs of readings that could accomplish the same thing. This is just the first one that struck me. I’d be interested in other suggestions in this vein.