Reply to Holtz

Robert C. Koons

September 1, 2004

In "The Compatibility of Naturalism and Scientific Realism" (Dec. 2003) , Brian Holtz offers two objections to my argument in "The Incompatibility of Naturalism and Scientific Realism" (in Naturalism: A Critical Appraisal, edited by William Lane Craig and J. P. Moreland, Routledge, 2000). His responses are: (1) my argument can be deflected by adopting a pragmatic or empiricist "definition" of "truth", and (2) the extra-spatiotemporal cause of the simplicity of the laws need not be God, or any other personal being.

In both cases, Holtz simply misconstrues my argument. I define "scientific realism" in such a way that it is incompatible with pragmatic conceptions of truth. Hence, I never argued that pragmatists can't be ontological naturalists -- they certainly can. Second, I define "naturalism" in such a way that the existence of any extra-spatiotemporal cause, whether personal or not, is inconsistent with it. The word "naturalism" has a large number of possible definitions -- I fastened on one that occurs quite frequently in the philosophical literature (my definition coincides exactly with David M. Armstrong's). It's my argument -- I get to stipulate what I mean by "naturalism" in the context of my paper. Thus, neither of Holtz's objections engage my central argument at all.

I think Holtz goes wrong by supposing that my paper is supposed to be an argument for God's existence, or for the existence of an extra-cosmic designer. However, it is not intended to be such at all. (I think there are good arguments for both of these conclusions, but the paper in question is not intended to provide one.) This doesn't mean that my argument is irrelevant to the debate over the existence of God. As I see it, my argument demolishes a common objection to many theistic arguments: that it makes no sense to look for a cause of the Big Bang, or the laws of physics, or the fundamental constants, because such things could be caused only by something outside spacetime, and this is obviously impossible. If I'm right, then the scientific realist is already committed to the existence of such an extra-spatiotemporal cause, and so no scientific realist can lodge this objection to the standard theistic arguments. (In addition, I should mention that this argument is only one of six independent arguments for this conclusion that I develop in my 2000 book with Oxford University Press, Realism Regained.)

Now, to be fair, there is one part of my argument, a subsidiary part, that Holtz does engage: my claim that if one is a scientific anti-realist (as Holtz is), then one cannot plausibly appeal to the authority/prestige of science to settle any ontological or metaphysical question (such as the existence of God or human souls). Holtz clearly thinks I'm wrong about this, but I find his argument (if there is one) exceedingly hard to follow. After all, if science tells us nothing about reality (i.e., real, objective reality), but only about "reality" (in the anti-realist, pragmatistic sense), then there's absolutely no reason why one shouldn't think that "reality" is naturalistic, but reality (no scare quotes) is inhabited by supernatural things. Why should any conclusion about "reality" give us any reason whatsoever for thinking that the same conclusion holds of reality? Holtz gives us absolutely no reason.

Perhaps this is what's going on: Holtz thinks that there is no such thing as objective reality, and reality that doesn't depend on human practices and preferences (in particular, those a priori preferences that constitute a large part of our theoretical practices). So, science tells us all there is to know about the only "reality" there is.

If this is Holtz's view, there are two huge problems with it -- problems that should, I think, persuade any naturalist worth his or her salt that this is not the path to take. First, there are the powerful arguments developed by the Polish logician Tarski against any pragmatic "definition" of truth. (1) For any sentence S, such as 'snow is white', it is a truism that 'S' is true if and only if S (e.g., 'snow is white' is true if and only if snow is white). (2) It is logically possible that snow is white, even though it is not useful to believe something expressible by 'snow is white'. (3) Hence, if 'is true' is logically equivalent to 'expresses something it is useful to believe', then it is logically possible that snow is white even though 'snow is white' is _not_ true. (4) Hence, if a pragmatic definition of truth were correct, it would be logically possible for snow to be white and not to be white (at the same time and in the same way). Contradiction. (5) Therefore, pragmatic definitions of truth are incorrect.

Holtz will, I assume, want to deny (2), but it is easy to imagine scenarios in which some fact holds, even though it is, all things considered, more useful to believe a sentence expresses the denial of that fact. Here again, the pragmatist faces a dilemma. Either his new "definition" of truth is supposed to express a truism, obvious to any competent user of English, or not. The first horn is obviously unacceptable, since many competent English speakers (myself included) find the pragmatic definition far from obvious or undeniable. So, the pragmatist must claim that his "definition" represents a discovery (a scientific discovery) about the essence of truth. Thus, the pragmatist must accept at least one case in which the correspondence theory of truth holds: namely, that his definition of truth corresponds with the real essence of truth. He then occupies a self-referentially inconsistent position.

The second critical problem with Holtz's position is that he gives us no reason for accepting his particular version of the pragmatic definition of truth (one that incorporates scientific standards of parsimony) over any of the myriad of alternatives. For example, what would be wrong with adopting instead William James's conception of truth, according to which we are free to adopt scientific standards of parsimony when dealing with scientific matters, but free to take into account various "existential" or even emotional considerations when dealing with religious, moral and interpersonal matters? All Holtz can do here is pound his shoe on the table, asserting that James is being "unscientific" (who cares about that?), or insist that a thoroughgoing scientistic attitude is more "useful" -- but where's the psychological and sociological evidence for that claim? And what to do about those who adopt radically different conceptions of what "usefulness" consists in, whose "goals" (note Holtz's casual reference to "our goals" on page 4) are radically different from Holtz's? Whose “goals” count? Those of Holtz and his pals? Why should anyone else care about that? The naturalistic pragmatist will quickly find himself mired in a morass of relativism.

There is another serious mistake in Holtz’s piece, although it is entirely tangential to my argument. Holtz admits that simplicity plays an indispensable role in theory choice about the fundamental laws, and that’s enough for my argument to work, but he’s wrong in thinking that “simplicity” here means only ontological parsimony. Holtz, and anyone else interested in the matter, should read Weinberg’s chapter on “Beautiful Theories”. For reasons of brevity, I quoted only Weinberg’s conclusions, but these conclusions are well supported in the book by a half dozen examples from the recent history of physics. The essential role of aesthetic standards of elegance in physics is quite close to being a commonplace in contemporary history and philosophy of science. You can find it well documented in Kuhn’s The Structure of Scientific Revolutions or, more recently, in Bas van Fraassen’s Laws and Symmetry.