definition, it is hardly surprising that he would consider philosophy of science qua philosophy of science useless—he's defined it as the set of all the work philosophers of science do that isn't useful! 'Philosophy of science is useless to scientists,' on that view, isn't a very interesting claim. By the same token, though, we might think that this isn't a very interesting refutation; let's give the spirit of Feynman a more charitable reading. If there's a more legitimate worry lurking behind the spirit of Feynman's critique, it's this: philosophers, on the whole, are not qualified to make pronouncements about the quality of scientific theories—they lack the training and knowledge to contribute non-trivially to any branch of the physical sciences, and while they might be well-equipped to answer evaluative questions, they ought to leave questions about the nature of the physical world to the experts. If philosophers occasionally make genuine progress in some scientific disciplines, cases like that are surely exceptional; they are (as Dewey suggests) the result of unusually gifted thinkers who are able to work both in philosophy and science (though probably not at the same time).
What's a philosopher of science to say here? How might we justify our paychecks in the face of the spirit of Feynman's accusations? Should we resign ourselves to life in the rich (if perhaps less varied) world of value theory and pure logic, and content ourselves with the fact that condensed-matter physicists rarely attempt to expound on the nature of good and evil? Perhaps, but let's not give up too quickly. We might wonder (for one thing) what exactly counts as "science," if only to make sure that we're not accidentally trespassing where we don’t belong. For that matter, what counts as philosophy and (in particular) what is it that philosophers of science are doing (useful or not) when they're not doing science? Surely this is the most basic of all foundational questions, and our answers here will color everything that follows. With that in