A Wrinkle in the System: Naturalism and the Crisis of Knowledge

James Carlin Watson

For those who haven’t given up on reality… those who haven’t gotten swept away by the neo-organic Continentalism where literary criticism meets grass-roots metaphysics and swirls into a mild relativism indistinguishable from radical relativism in all but its linguistics… for the rest of us, naturalism (philosophical or scientific; however you wish to qualify it) has been a driving force of late. Its programmatic orthodoxy has dripped into every major branch of philosophy and science, and yet it is one of the least defined, least understood (in its implications) terms on the market. I’m not saying we have a handle on all the other ‘isms’ that pervade our beautiful field. Terms have always been problematic and the rate of the introduction of new ones seems exponential at times: physicalism, materialism, nominalism, perdurantism, presentism, foundationalism, functionalism, instrumentalism, realism, and on and on. However, the problem with naturalism swings a little differently than these others. Let me walk through a little bit of history to show why.

After the fall of verificationism (there’s another one) and the diminishing project of the positivists, Karl Popper and W.v.O. Quine induced the discipline toward a more reasonable methodology, introducing falsification while retaining a great faith in the empirical methods of the natural sciences. Thus the project of naturalism was born, sort of.

Naturalism as an idea has been around since the pre-Socratics and was developed into a tenable empiricism with Aristotle. The movement shaped up with Descartes and Locke, and Kant and Hume put new faces on it within their respective programs. But naturalism qua naturalism, in full bloom, was first introduced by Quine in his push for a naturalized epistemology. Immediately prior to Quine, Dewey had an explicitly pragmatic naturalism, but the distinctiveness came with Quine’s move. This move is important because it marks a turn in the approach to philosophy that even the positivists could not have predicted, and one which has developed into an all-encompassing methodology for most of analytic philosophy. The only exceptions to this radical shift have been the pragmatists, instrumentalists, intuitionists, and pure rationalists. And of the few of these still rummaging around the discipline (instrumentalists like Bas van Frassen are still prolific) they take arguably naturalistic forms. This may still sound like quite a bit of resistance, but anyone working with science is under a great deal of pressure to form a realist notion of science as correspondence with reality. Pragmatists are forced into a form of instrumentalism by their adherence to science as discovering useful information rather than truths about reality. Instrumentalists who hold instrumentalism apart from pragmatism find science to be merely one avenue of discovery for reality, making room for other inquiries in the form of poetry or literature, spirituality and religion. But do not imagine that it is as simple as that. Few Christian philosophers of religion would claim that they are instrumentalists. However, the most prominent instrumentalist philosopher of science is Bas C. van Frassen who is a Catholic. (Try and put that one together.)

So what does a good naturalist hold? There appear to be three main “methodological dispositions” held by naturalists, according to Michael Rea of Notre Dame.[1]

These include a strong adherence to the methods and findings of all major/respected branches of the empirical natural sciences. The term “natural sciences” is not without a great deal of controversy, but most agree that this includes, at least all the major fields of scientific inquiry found at a major university, including physics, geology, chemistry, biology, archaeology, and sometimes psychology or neurosciences and sociology or anthropology. The last of these are even more controversial as you can imagine. The second of the three dispositions is a rejection of a priori, or “first”, philosophy, that is, science should inform philosophy through its legitimate methods and not the other way around. The implication is that true knowledge is based solely in actual empirical data or deduced from such data via certain logical parameters set by philosophy a posteriori. The last disposition is the causal closure of the natural universe. This precludes any super- or extra-natural causal forces intervening in the lawful intricacies of the universe. This does not preclude theism, as some have thought, for there are several versions of theism that do not adhere to any kind of miraculous intervention to which naturalists may freely adhere. This is because the natural sciences are supposed to be neutral with regard to the existence of such a being.[2]

Neither does this imply any sort of strict reduction with regard to empirically unavailable items such as mental events. It is presumed that naturalism is compatible with non-eliminative, non-reductive physicalism with regard to mental events. Therefore a position is plausibly naturalistic as long as it rejects non-scientific knowledge claims (this does not refer specifically to empirical claims, as problems with scientific tools such as ‘simplicity’ show), a priori philosophy, and any sort of metaphysical dualism.

Individual definitions of naturalism take on the distinctives of the program in which they are invoked. Philosophers of mind are interested in naturalizing intentionality, Philosophers of science are especially concerned to reject Creationist accounts of natural development, Epistemologists are concerned to rule out a priori methods of knowing, like theistic proofs or religious experience. But what of these programs? As long as they do not make any universal claims as to the only entities that exist or the only legitimate methods of knowing, they are merely inferences to the best explanation, just as any other program of inquiry. If they do make these universal claims, then they have a good deal of justification to do, but most don’t… at least not when pressed about it. It is true that scientists and philosophers make unwarranted claims as to the power of their particular system, but these are not, to be charitable, examples of the system itself, but of scientists speaking non-scientifically. These can be forgiven, but their programs remain under scrutiny. If they admit that warrant is the ultimate deciding factor (with past success and simplicity as corollaries), then theists, supernaturalists that is, retain a pretty stout leg to stand on.

So why do I say that there is a wrinkle in the system? The system I am concerned with is the philosophy of science. While naturalism is a widely held, well-regarded philosophical and scientific position, without proper justification for certain beliefs within the system it can be irrational to hold. For example, the prime target of most anti-naturalist arguments has been the broad scope and rigidity of naturalism when construed as a strict philosophical thesis. This means those who hold a form of naturalism as philosophy, such as epistemological naturalism, ontological/metaphysical naturalism, or methodological naturalism run into certain self-referential problems that conflict with certain claims of natural science, to which naturalism is supposed to adhere wholeheartedly.

Take an argument against naturalism from William Lane Craig concerning its epistemological version. The claim, “We should only believe what can be scientifically proven” cannot itself be proven by any scientific method, and therefore, if it is true it should be rejected, and also if it is false it should be rejected.[3]

Some might say this statement sounds like verificationism and would not be promoted by a contemporary naturalist, but it seems any qualified version falls prey to the same attack. Any statement making claims about empirical methods cannot be proven by empirical methods. One might say that we have a certain amount of rational warrant for believing in empirical methods and I would agree. But to employ a rationalist epistemology is not allowing science to inform your philosophy. You have merely justified your method with an a priori notion of warrant, based on prior accuracy, the accuracy of which is determined by cognitive capacities assumed to have the function of locating truth or reality, which naturalism eschews. And so one might say that empiricism can be chosen rationally based on pragmatic grounds, and again I would agree. But anyone who chooses a pragmatic approach is tied inextricably to an instrumentalist view of science as useful and therefore detached from a strong notion of truth as reality, in turn undercutting the realism and correspondence theory of truth to which naturalists desire to be tied. Similar problems emerge for ontological and methodological naturalism, which make claims about every real entity that exists or every legitimate method for attaining knowledge, for which science, in its methodology and findings, makes no claims.

However, I think that naturalism can be held consistently, without self-referential problems and without problems with justification, but I think the cost is high; therefore a wrinkle remains. It is plausible to hold naturalism as a research program, rather than a strict philosophical position. This involves a belief structure that is acceptably based in epistemic warrant but one which is not chosen rationally and cannot be judged internally rational given that it can only be judged on the basis recognized as acceptable from within the research program in which one is working. Michael Rea makes this point in his book World Without Design: The Ontological Consequences of Naturalism. He says, “…[A] research program might also generate evidence that some other research program is to be accepted. Still, it cannot be on the basis of this evidence that one accepts the favored program. For once the old program is rejected, the evidence arising out of the old program in favor of the new cannot be recognized as evidence.”[4]

He goes on to say that the best a research program can be is self-supporting, and that if a new program is adopted and found to be self-supporting, rather than one that “prescribes its own rejection,” then it is a consistently held position. He adds that this is no special deficiency for naturalism, for all belief systems seem to be held on these grounds, that is, as far as they are research programs. The point is that a research program can be rejected because of evidence, but it cannot be adopted because of evidence. Evidence can convince you that your program is incoherent or unreasonable, but not that any other one is correct. The attempt in the rest of Rea’s book is to show that naturalism has certain implications that philosophers and scientists are not willing to make.

So what is the wrinkle for naturalism as a research program? The central argument posed by Rea concerns the acceptance of material objects into one’s ontology. Rea says that material objects have intrinsic, non-trivial modal properties for which an ontology must account. He argues that no reasonable naturalist can hold the three methodological dispositions of naturalism and retain a realist view of material objects. I, however, think there are other plausible refutations of this version of naturalism.

One could begin by challenging the knowledge claims of the methodological disposition to believe only scientifically acceptable facts as truths. This is only a matter of bringing everyday beliefs to light that challenge this assumption. Did you eat breakfast this morning? It would be difficult to prove if it has been more than eight hours, but perhaps your metabolism and some forensic medicine could be of assistance. Does this possibility make you rely more or less on your cognitive faculty of memory? It seems not. But say it does, consider another example from the movie Contact. Matthew McConaughey’s character asks Jodie Foster’s character, who is a stringent naturalist, “Did you love your father?” (the father is now obviously deceased). She replies in the affirmative and McConaughey follows with, “Prove it.” Are there rationally acceptable and reliable knowledge claims based on methods other than standard scientific inquiry? The question is some what convoluted, but if by standard scientific inquiry we are referring to non-a priori-based empiricism, it seems so. Are they defeasible? Absolutely, just as any good thesis for an acceptable falsifiable scientific theory should be.

But the rub for naturalists comes with the fact that accepting rationally justified theories and assumptions based on a good deal of warranted assertability immediately opens the door for knowledge claims (at least in the context of justification rather than the context of discovery) from apparently non-scientific origins, i.e. memory, testimony, natural theology, and religious experience. The naturalist seeks shelter from such audacity, but has yet to successfully find or defend it.

Another tack could be to deduce from the best available scientific information a piece of evidence contrary to a methodological disposition. Richard Swinburne uses the well-accepted Bayes theorem to prove the existence of God. Michael Behe takes the best available molecular biology and defends the thesis that at a certain point complexity becomes irreducible. One example of this, the route I generally follow, takes queues from the kalam cosmological argument. The naturalist will not accept the rationalistic, a priori deduction of the kalam argument, so a sort of extension is needed to make it fruitful. The best available scientific data places the origins of our universe somewhere in the neighborhood of 13 billion years ago in a Big Bang-type event initiating from an infinitesimal cosmological singularity and expanding, based on our best knowledge of cosmic laws, toward thermodynamic equilibrium whereupon the universe will be considered dead. The question arises as to the cause of this singularity, an understanding of what is meant by ‘infinite density’ of the initial singularity, and how the matter that is so densely packed came to exist in the first place. The most obvious problem involves the fact that there was no time before the big bang – none, zero, zip – because, as our best theories tell us, time itself began at the Big Bang. This means that no change relationships took place in the form of events, defined minimally as consisting of a before and after, prior to this event. Now, given their reluctance to accept supernatural causation as well as the thesis that something could arise from nothing, the naturalist is in a quandary. And this quandary is not by nature empirical, it is theoretical. There is the possibility of finding things that come into being out of nothing and then, alright, problem partially solved. Quarks might give us clues to this, but there is still no new matter produced in quantum physics. And this is not the most prevalent position. The central tack taken by most naturalists is the presupposition of some form of naturalism as philosophical thesis. They then claim that the hypothetically completed natural sciences preclude the existence of non-physical beings, especially non-physical minds. But as we have seen, this direction is fruitless for the naturalist. Now, on the research program, it seems that the naturalist is warranted in giving up his or her naturalism in favor of a philosophical theory that could make more sense out of the situation, but in doing so they make themselves susceptible to the remarkable progress made in philosophy of religion, which makes extremely strong cases for supernatural causation, for example, Alvin Plantinga’s unique use of evolution to argue that theism provides the simplest argument to the best explanation for certain questions of reality and knowledge without reducing it to merely (and untenably) God-of-the-gaps theology.[5]

As well, Timothy O’Conner’s use of the nature of causation to prove that nature does not preclude interference.[6]

Many examples exist in the literature in defense and rejection of naturalism as a philosophical thesis. My task here is merely to point out the difficulties in formulating a consistent naturalist position and to identify some of the problems to be overcome before this can be a compelling option. I am not saying that it cannot be done. I think Michael Rea has done a great deal toward making naturalism plausible and consistent while at the same time showing that it is not appealing in its implications for a realist ontology. The naturalist has his or her work cut out as far as many philosophers are concerned. The fact that few have given the concept much attention is merely a testament to the pervasiveness of the problem rather than its insignificance.

[1] Michael Rea, World Without Design: The Ontological Consequences of Naturalism (Oxford University Press: New York, 2002).

[2] But see Alvin Plantinga’s “Methodological Naturalism?” in Robert Pennock, ed., Intelligent Design Creationism and It’s Critics (MIT Press: Cambridge, 2001).

[3] “Christianity vs. Scientific Naturalism,” A Debate Between William Lane Craig and Garret Hardin, The Veritas Forum at the University of California at Santa Barbara, 1997?.

[5] Alvin Plantinga, “Methodological Naturalism, Pt. 1,” Origins & Design 18:1, 1997.

[6] Timothy O’Conner, “Causality, Mind, and Free Will,” Soul, Body, and Survival, Kevin Corcoran, ed. (Cornell University Press: Ithaca, 2001), and “Agent Causation,” in O’Conner, ed., Agents, Causes, and Events: Essays on Indeterminism and Free Will (Oxford University Press: New York, 1994).