Two definitions of naturalism
There are two basic ways to approach the definition of naturalism.
The first way is that which identifies naturalism with some specific thesis about the way the world is. We can call this the “fixed definition” approach. The problem is that fixed definitions tend to be embarassingly vulnerable to refutation. Sometimes a refutation of naturalism under a fixed definition is a priori. (For example, one might identify naturalism with the claim that everything that exists has coordinates in space/time. But this prompts us to ask what the coordinates in space/time are for space/time. If we determine that this question makes no sense, then we are forced to deny that space/time exists in which case nothing exists to locate everything else.) Other times the refutation of a fixed definition is a posteriori. (For example, if we identify naturalism with the specific claim that mental events are physical events, then the failure of reductionist theories of mind refutes naturalism.)
So it is no surprise that naturalists, keen to identify a form of naturalism that is not vulnerable to such refutation, have gravitated toward defining naturalism in terms of an open definition and that cashes out as openness toward whatever-science-comes-up-with-in-the-future.
The open definition is no longer prone to embarassing a priori or a posteriori defeat. But at what cost?
One thinks here of Tony’s Pizzeria. It used to be prone to vandalism from neighborhood thugs. Then Tony purchased some Mafia protection. Now his joint is no longer prone to spray-painted doors and broken windows. But the cost of protection is great. Tony now has to pay so much to the Mafia that he makes no profit anymore. He is essentially working simply to pay the Mafia which sorts of begs the question, doesn’t it?
Fortunately an open definition of naturalism defined in terms of the deliverances of future science doesn’t threaten to break the kneecaps of those who buy into it. Nor has anybody who accepted it been tossed into the East River for doing so (at least not to my knowledge). But it does extract the high cost of rendering naturalism into a vacuous cipher that doesn’t mean much of anything. “You believe in whatever science will define the world to be in the future? Sounds good, I will too. Now where do you want to go for lunch?”
Open definitions of Theism
The interesting thing is that naturalists aren’t the only ones to try this Harikiri defense of their beliefs. Theists have occasionally tried it as well. And believe me, the results were not pretty.
Take liberal Anglican bishop John Robinson, for example. He’s the kind of English bishop who calls to mind this old joke:
“My bishop is excellent.”
“That’s good to hear. Is he a theist too?”
Consider this excerpt from Robinson’s bestselling 1963 book Honest to God:
“God is, by definition, ultimate reality. And one cannot argue whether ultimate reality exists. One can only ask what ultimate reality is like–whether, for instance, in the last analysis what lies at the heart of things and governs their workings is to be described in personal or impersonal categories. Thus, the fundamental theological question consists not in establishing the ‘existence’ of God as a separate entity but in pressing through in ultimate concern to what Tillich calls ‘the ground of our being’.” (Honest to God, 40th anniversary ed., p. 29)
In this passage we see Robinson defining God with whatever ultimate reality turns out to be. If it turns out to be a personal agent then God exists. But if it turns out to be impersonal matter then God exists. Whatever ultimate reality is, that’s what we call God. And so in virtue of believing in ultimate reality one believes in the existence of God.
By defining God in this way Robinson manages to protect theism from refutation. But he does so by defining theism in such a way that it is consistent with atheism!
And this is precisely what the advocate of an open definition of naturalism does. As I already noted in an earlier essay, if naturalism is belief in whatever science establishes, and science could conceivably establish the existence of a non-physical agent who interacts in the world (and through the process of abduction this agent could reasonably believed to be God), then naturalism is consistent with believing in God.
This is where open definitions get us. They secure one’s position from refutation by leaving us with the absurdity of theism that is consistent with atheism and naturalism that is consistent with supernaturalism.