IMPLICATIONS

Let me comment briefly on the implications of a pragmatic theory of explanation for two contested issues in the philosophy of science.

a. Realism versus Antirealism

Of course, a good deal depends on how you define “realism” and “antire­alism.” According to van Fraassen's formulation, the realist aims to give “a literally true story of what the world is like,” while the antirealist aims to give “theories that are empirically adequate” (pp.

The first point I want to make is that, contrary to what might be thought, a pragmatic theory of explanation does not commit one to anti­realism. Consider a theory of the sort I offer for pragmatic explanation­sentences of the form

E is a good explanation for an explainer to give in explaining q to an audience.

The theory proposes several truth-conditions for sentences of this form, but the important one for the present issue is that E provides a correct answer to question Q or that it is reasonable for the explainer to believe it does. The fact that E provides a correct answer to Q is not by itself sufficient to make E a good explanation of q; further contextual condi­tions need to be satisfied. But these contextual conditions in no way pre­vent a realist construal of “correct answer to Q” as one that, among other things, provides a “literally true story.” The contextual conditions do not require that we construe a “correct answer” to be one that simply “saves the phenomena.” By reference to the context of Rutherford's 1911 expla­nation, we can determine the need to provide an explanation of the scat­tering that appeals to the inner structure of the atom. We may evaluate Rutherford's explanation highly, in part because it satisfies such contextu­ally determined instructions. But this need to appeal to context does not mean that we must construe Rutherford's explanation nonrealistically.

Indeed, so far as I can see, even van Fraassen's own evaluative theory— which earlier I argued is not pragmatic—does not require an antirealist posi­tion of the sort he himself urges. We are supposed to evaluate the goodness of the explanation “P in contrast with X because A” by determining whether proposition A is “acceptable” or “likely to be true,” and by determining cer­tain probabilistic relationships between A, the contrast class X, and the other answers being considered. None of this would seem to require antirealism. And the fact that the contrast class and alternative answers are determined contextually in no way precludes a realistic construal of answer A.

Conversely, pragmatism with regard to explanation does not commit one to realism. A “correct answer to questions Q” might be construed antirealistically as one that “saves the phenomena.” Or, perhaps better, one might drop the condition that the explanation provides a correct answer to Q in favor of the condition that the explanation provides an answer to Q that saves the phenomena. This modification is in no way precluded by the need to appeal to contextual facts about an explainer or audi­ence. (There are other more compelling reasons to resist antirealism that I explore in chapter 11. My point is only that the need to invoke explainers and audience is not a compelling reason.)

b. Relativism versus Absolutism

Pragmatism with regard to explanation, particularly strong pragmatism, is a form of relativism. The truth-value of a strongly pragmatic explanation­sentence will vary with explainer and/or audience. But this relativism does not necessarily commit one to particularly virulent forms such as subjectivism or (Feyerabendian) anarchism. For example, it will not be the case that an explanation will be a good one for an explainer to give an audience if it simply satisfies any criteria set by the explainer or audience. For one thing, the explanation must satisfy some truth or confirmation requirement. For another, there may be certain criteria the satisfaction of which by the explanation is valuable for the explainer or audience, de­spite their own beliefs about these criteria. The form of relativism I would support could agree that the introduction of laws, causes, unification, and so forth, are general methodological criteria valued in science. They are “prima facie” virtues. But in giving assessments of explanations of the sort I have been describing—in giving illocutionary evaluations—they cannot be treated as necessary or sufficient conditions. They are relevant, but they must be combined in appropriate ways with pragmatic information.