In “Not even wrong: The many problems with naturalism” I argued that the person who endorses “naturalism” faces a dilemma in terms of defining what it is that they believe in. The problem can be summarized in the choice between a fixed or an open definition of naturalism.
The problem with fixed definitions of naturalism
On the one hand, they could opt for a fixed definition by saying that naturalism equates to a particular concrete description of how the world is based on the current deliverances of science. For instance, many philosophers of the past have adopted the thesis of materialism according to which (on one definition at least) everything that exists has spatial coordinates. Fixed definitions like this have the benefit of providing clear content. But they have the downside of being particularly prone to falsification. (Where was that quale of peppermint again? Where’s the number three? Where’s the speed limit of Highway 101?)
Fixed definitions of naturalism also appear to be unjustified. Think, for example, of Mazda’s recent decision to stop building Rotary engines with the discontinuation of the RX-8. The prospects for the rotary engine being built again in the near future are not bright given their poor fuel economy. But it would surely be unjustified to declare that Mazda will never build rotary engines again. We just don’t know how automobile technology will advance in the future and thus current projections on the future course of development of technology are unjustified. Similarly, we don’t know how science will develop in the future and thus current projections on the future course of science are likewise unjustified.
The problem with open definitions of naturalism
On the other hand, there are open definitions of naturalism. According to these definitions, naturalism is defined so as to ensure that it remains open to whatever future descriptions of the world science may come up with. This definition avoids the embarassing failure-prone history of fixed definitions like the definition of materialism noted above. It is, in short, cutting anchor so the boat is free to rise as high as the tide.
But open definitions gain that tractability at the cost of positive content. This becomes a serious problem since naturalists describe themselves as such in part to make clear their rejection of “supernaturalism”, a category in which they place all sorts of things like God, souls, ghosts, fairies, et cetera. So whatever science comes up with, they want to ensure that it excludes these entities. Yet, if it is conceivable that a future science could countenance some of these verboten entities, then we have no real way to say that a future science will not in fact include these entities. And if you’ve defined naturalism in such a way that it is consistent with being a theist, then what’s the point?
Lowder’s rhetorical opening
This brings us to Jeffrey Jay Lowder’s stumbling critique of my argument against naturalism. (You can read it here.)
Lowder begins:
“Randal Rauser really doesn’t like the argument from the history of science (AHS). After I refuted his initial objections to AHS, he seems to have abandoned those objections. Instead, he now takes issue with the definition of metaphysical naturalism itself….”
I am not sure if Lowder really thinks I “abandoned” my objections or if he’s just engaged in trash-talking. In point of fact, I have demonstrated how his AHS fails from the theist side. My shift to discussing naturalism is simply a matter of demonstrating how AHS also fails from the naturalist side since Lowder cannot even provide a viable definition of naturalism. But kudos to Lowder for giving a summary of the conversation that is about as reliable as Rush Limbaugh’s summary of Obama’s State of the Union Address.
A general rule of thumb is that you lead with your strong points. This doesn’t bode well for Lowder’s case. He begins like this:
“”But what about all those high-falutin’ philosophers, from both sides of the aisle, like Plantinga, Swinburne, Moreland, Draper, Schellenberg, and Smith (to name just a few) who think that metaphysical naturalism is a serious alternative to theism?” I guess Rauser would say that he knows better than they do; they simply (and quite literally) do not know what they are talking about.”
Yawn. And I guess that Lowder thinks O.K. Bouwsma, Michael Rea and Bas van Fraassen (one of the leading philosophers of science writing today) don’t know what they’re talking about.
Lowder’s fixed definition
Now on to important matters. What is Lowder’s response to the fixed definition / open definition dilemma? His response, it turns out, is to offer a definition with fixed and open aspects. Apparently he thinks borrowing errors from two sources will result in each canceling the other out. But alas, that is like thinking that because the Ford Pinto and Chevy Vega were both horrible vehicles, that a jointly built Ford/Chevy Pintga would be an improvement.
Here is the fixed bit of Lowder’s definition:
“An entity is logically compatible with N if and only if either (a) it is a physical entity, or (b) it is ontologically or causally reducible to a physical entity.”
And since things like souls and God are neither physical entities nor ontologically or causally reducible to physical entities, then science is guaranteed never to discover evidence of such things in the future.
Really? Based on what? Lowder’s definition here is dogmatism, pure and simple. It has the same justification problem of all fixed definitions because Lowder simply is not in a position to make projections into the future of the kinds of entities that science will, and will not, discover. Imagine an explorer who is travelling over unfamiliar territory. For the last month it has been hot and dry and he rides into a fort to buy supplies before heading out again into unknown terrain to travel for an undetermined period of time before arriving in distant Veritas City. Now imagine if our explorer reasoned like this:
Over the last few weeks I’ve encountered little water and it’s been hot. So I’ll bring lots of water for the journey and no blankets or warm coats.
You’d probably think that was a foolish decision because the explorer is simply not in a place to make projections about the kind of terrain he’ll encounter in the future. It could be that in the next week he will pass out of the desert and into cool and wet mountains. He simply has no clue.
Yet this is precisely the kind of foolish judgment that Lowder is making.
Except that things are even worse. Imagine that the traveller had passed through a variety of radically diverse environments in the last few weeks. That would render his sure projections about the future trail even more foolish. Yet, the modern story of scientific progress is a story of one radical transition after another. At the end of the nineteenth century physicists were telling their students not to enter physics because all the big questions had been answered, and the only progress to be made was in decimal points. Then along came Einstein.
Today even the most fundamental, basic questions like “What is matter?” are up for grabs. We have absolutely no idea what revolutions will wait for science in the next few decades let alone the next few centuries. So to adopt a view like N is a dizzying piece of dogmatism.
Lowder’s open definition
What about the open part of Lowder’s definition?
To begin with, as I already noted Lowder is happy to recognize the existence of abstract objects. I think it is really important for the reader to grasp what Lowder is conceding here. Abstract objects are generally believed to be inert, atemporal, spaceless, necessarily existent objects (often called “universals”) which are somehow exemplified in concrete particulars in space-time. Consider a couple examples:
(1) The color red is an inert, atemporal, spaceless, necessarily existent object which is somehow exemplified in the fire truck driving down the street and the bicycle in my garage.
(2) The proposition Snow is white is an inert, atemporal, spaceless, necessarily existent object which is somehow exemplified in the statement “Snow is white” and the statement “Schnee ist weiss.”
This is stunning! How is it that abstract objects can enter into this utterly mysterious exemplification relation with concrete particulars? And what are these abstract objects anyway? How is it that there can be an infinite number of objects just existing as brute facts?
Lowder’s response is simply to quote Paul Draper: “[W]hile our knowledge of nature may provide reason to believe that nothing is supernatural, it provides little basis for the further conclusion that nature is all there is.”
But that’s no response at all. It’s little more than a mantra. The fact remains that Lowder accepts with no problem at all the stupefying existence of an infinite number of mysterious abstract objects. And he has no problem with them entering into utterly mysterious and inexplicable exemplification relations with concrete particulars. But when it comes to non-physical agencies interacting in the world, that’s suddenly one mystery too far. Surely there could be no such things, he says.
Except that Lowder then says this:
“I want to emphasize that I don’t rule out the possibility of a future scientific discovery which could provide evidence for souls (or shmouls). If such evidence is discovered that would be evidence for T and against N. But then it follows from the probability calculus that the non-existence of souls is evidence for N and against T”
Now this is really perplexing. Lowder now adds that he is open to science establishing the existence of non-physical substances that are neither physical nor natural which interact in the world.
This is like our traveller at the fort conceding that the trail ahead may indeed get cold and wet. Obviously you would think that is a reasonable concession. But then you would surely advise him to take the next step and drop his decision to take lots of water but no blankets.
And that is our advice to Lowder as well. Good for him for admitting that science may discover entities that falsify N. But then why not abandon his commitment to N?
His answer, presumably, is that he still thinks this unlikely. But as I have explained, he has no way to establish that it is highly unlikely that science will falsify N. Indeed, he is in a position where the evidence is inscrutable. And if he has no idea on the likelihood that science will falsify N in the future, then he ought to be agnostic about N.
So to sum up, to the extent that Lowder’s naturalism has fixed content he ought to be agnostic about it. All the more so given that he is so willing to countenance the wonderful world of abstract objects.
At this point even the defender of the invisible gardener is blushing.

