“The trouble with physicists who denigrate philosophy is that they read the wrong philosophers, which sad to say is most philosophers.”
Glymour distinguishes between two different approaches to philosophy, noting that the one that is more useful is not the one most philosophers identify with:
By their fruits ye shall know them. Compare Plato and Aristotle, superficially. Plato made no effective contributions to how to acquire true belief. Plato had analyses and counterexamples (The Meno) and a huge metaphysical discourse; we still don’t know necessary and conditions for virtue, the subject of the Meno. Aristotle had axioms for logic, a logic that was pretty much the best anyone could do for 2300 years. He had a schema for conducting inquiry (albeit, not a terribly good one, but it wasn’t bested until the 17th century). Euclid was not a contemporary of Plato or Aristotle, but he systematized the fragments of geometry then current. The result was a theory that could be systematically investigated mathematically, applied in a multitude of contexts, and that constituted a stalking horse for alternative theories that have proved better empirically. Euclid has no formal definition of “point” that plays any role in his mathematical geometry. Just imagine if instead the history of geometry consisted of analyses of necessary and sufficient conditions for something to be a point.
Newton, von Neummann, Schulte, Ramsey, Hilbert, Bernay, and Lewis come in for praise for their axiomizations and systematizations of physics, decision theory, first-order logic, and the logic of counterfactuals. Meanwhile, “Socratic thinking has no comparable fruits.”
That way of conceiving the landscape of philosophy informs Glymour’s answer to this question from Marshall:
Several prominent scientists, including the late Stephen Hawking, ask: if philosophical questions are so vague or general that we don’t know how to conduct experiments or systematic observations to find their answers, what does philosophy do that can be of any value? Maybe in the past it was creative and was the basis of science, but that was then: why do philosophy now? How do you answer them?
Here is Glymour’s reply:
The trouble with physicists who denigrate philosophy is that they read the wrong philosophers, which sad to say is most philosophers. Had they read Peter Spirtes (CMU), or Jiji Zhang (Lingnan, Hong Kong) or Frederick Eberhardt (Cal Tech) or Oliver Schulte (Simon Fraser) or Teddy Seidenfeld (CMU) or Scott Weinstein (Penn), they might have had a different opinion. Looking back to the last century, philosophers (e.g., Bertrand Russell) made major advances in logic, created the basics of behavioral decision theory (Ramsey), co-created computational learning theory (Putnam), and created the causal interpretation of Bayes nets and the first correct search algorithms for them (Spirtes, Glymour and Scheines)…. One of my colleagues, Steve Awoody, made a central contribution to the creation of a new branch of mathematics, homotopic type theory.
The reason a handful of philosophers were able to make these contributions is relatively simple: they were well-prepared and in academic or financial circumstances that enabled them to think outside of disciplinary boxes and develop novel ideas in sufficient detail to make an impact, or in Ramsey’s case, lucky enough to have a later figure really develop the fundamental idea. It is a rare university department that allows for such thinkers.
Statistically, the physicist critics are pretty near correct. Philosophy of science is a deadletter subject filled with commentary book reports on real scientific work, banal methodological remarks (e.g.,scientists of a time don’t always think of true alternatives to the theories they do think of; scientists sometimes have to think at multiple “levels”), and “mathematical philosophy” some of which is very interesting but none or which is of practical scientific relevance. I once was interviewed for a job at UCLA. Pearl was invited to dinner with me and with some of my potential colleagues. Pearl managed to compliment me and insult the others with one question: “Why don’t the rest of you guys do anything?” In the context of your question, Pearl’s was a very good question.
Here is my answer to Pearl’s question: Demographics and history have killed philosophy of science. The Logical Empiricists, European émigrés just before and after World War II, had almost no interest in methodology, did not engage much in the developments in statistics or computation, and basically gave philosophy of science a reconstructive turn—the heritage of their neo-Kantianism. They educated two generations of American philosophers interested in science. By the 1980s computer science and statistics increasingly took over methodology, and (at least in computer science) began to address some of the issues that motivated me a generation earlier to study history and philosophy of science. After that, someone with my interests would have to be either very ambitious or foolhardy or not really smart to study philosophy rather than statistics and machine learning. Born too early, I was.
There’s more (and more kinds of) philosophy of science than ever before. Glymour knows that, of course, so when he talks about philosophy of science being “killed,” he doesn’t mean that no one’s doing it. What he means, rather, is that it is Socratic, in the sense of fruitless. I would imagine that many philosophers of science would disagree. Thoughts welcome in the comments.