Philosophy and science
The distinction between philosophy and science is sometimes held to be, by comparison, a simple matter. Though Isaac Newton called his Principia, the first great text of modern theoretical physics, a work of “natural philosophy,” many philosophers since would have said that it was not a work of what I have called “formal philosophy.” The reason they would have given is that Newton's work was about (admittedly, very abstract) empirical questions—questions to which the evidence of sensation and perception is relevant.
Formal philosophy, on the other hand, deals with questions that are conceptual— having to do not with how the world happens to be but with how we conceive of it.But this way of making the distinction between philosophy and science seems to me to be too simple. Much theoretical physics is very difficult to connect in any straightforward way with empirical evidence, and much philosophy of mind depends on facts about how our human minds happen to be constituted. It will not do, either, to say that the use of empirical evidence in science involves experiments, while in philosophy it does not. For thought experiments play an important role in both science and philosophy, and many branches of the sciences—cosmology, for example—have to proceed with very few, if any, experiments, just because experiments would be so hard to arrange. (Imagine trying to organize the explosion of a star!)
Nevertheless, there is a difference—which, like the difference between philosophy and theology, is by no means absolute— between philosophy and physics, and it has to do with the fact that the kind of empirical evidence that is relevant to the sciences must usually be collected a good deal more systematically than the evidence that is sometimes relevant in philosophy.
Even this difference is a matter of degree, however. In the philosophy of language—in semantics, for example—we need to collect systematic evidence about how our languages are actually used if our theories of meaning are to be useful.
As we saw in Chapter 2, the discovery of cases such as the ones that Gettier thought up can play a crucial role in epistemology. But there is a pattern in the history of Western intellectual life, in which problems that are central at one time to philosophy become the basis of new, more specialized sciences. Thus, modern linguistics grows out of philosophical reflection on language, just as economics and sociology grew out of philosophical reflection on society, and physics grew out of Greek, Roman, and medieval philosophical reflection on the nature of matter and motion. As these special subjects develop, some of the problems that used to concern philosophers move out of the focus of philosophical attention. But the more conceptual problems remain.This pattern is reflected in the fact that where philosophy and the specialized sciences address the same problem, the more empirical questions are usually studied by the scientists and the less empirical ones by the philosophers. That is the sense in which philosophy really is a primarily conceptual matter.
The division of labor between science and philosophy has been productive. While philosophical work has often generated new sciences, new philosophical problems are also generated by the development of science. Some of the most interesting philosophical work of our day, for example, involves examining the conceptual problems raised by relativity and quantum theory. To do this work—or, at least, to do it well—it is necessary to understand theoretical physics. But it also requires the tools and training of the philosopher.
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