A Necessary Pairing: Evolutionary Theory and Realism

In this post, I would like to briefly explore some reasons why I think those committed to the theory of evolution (via the extended, modern, or some variation of the core synthesis) should give very careful consideration to their implicit metaphysical commitments. What often gets lost in popular public bantering between proponents/expositors of evolution and (typically religious) detractors is that the theory makes certain claims about reality. And these claims purport to be true, or at least the evolutionary theorist usually claims they are true in some way. For example, natural selection is something that occurs and acts on genes within species structure, population groups, etc. Another example might be common ancestry and speciation events are actual historical events. These examples might be oversimplifications, but my point is simply that are a lot of claims baked into the theory. One must decide how important for components of the theory are literally true. Without a commitment to some form of realism, the evolutionist loses the grounds by which to make a truth claim about his theory.

To start, let us say that the evolutionist is a nominalist. Where does this leave the evolutionary theory? It seems we would be left with anti-realism. One reason is that “species” (or class, phyla, etc.) would be a mere linguistic convention or some logical or semantic placeholder that does not correspond to anything real. If there is nothing essential to a species, then how can we construe speciation events along realist lines? Without a commitment to real species distinction, it is difficult to see how the theory can make consistent truth claims. For example, that at some point there was a Pan-Homo split.

The evolutionist could perhaps be a conceptualist. On this view, something like homo habilis would be a (presumably reducible) mental concept. You or I could think and speak about the same general idea (maybe), but there would still not be anything extra-mentally real about homo habilis. This also leads to anti-realism about the evolutionary theory. There are numerous other anti-realist views. And each of these would be equally unhelpful to the evolutionist.

If one is going to be realist about evolutionary theory, then some type of metaphysical realism is necessary. A committed naturalist/materialist might balk at this. But they have no other good options. If a class, species, group, etc. are not real things in some way, then what can the theory help us know about the genuine history of biological organisms, their variation, operation, and so on? Can one really execute a proper taxonomy or determine LCAs without upholding some type of realism? Surely, one would not want to argue that a critical speciation event such as CHLCA was not a real occurrence (whether more complex and gradual or sudden). But if species are not real things, then what can we make of CHLCA? The answer is not very much. The evolutionist is aiming at the truth in scientific results, and realism must be part and parcel of that.

Since the evolutionist should be some type of realist, what type of realist should he be? Platonism might be an option. There are, of course, myriad variations, but one might take a basic version and think the particulars of biological study are merely instantiations of universals that exist in another realm. There is a library of Platonic forms by which the evolutionary biologist could classify and organize his work. Besides the standard objections to Platonism, I think there is some extra baggage in applying this theory to evolutionary biology. The Third Trilobite Argument is surely a problem to address. But questions of supervenience, causal relations, and others seem like they would be quite difficult to overcome. Here I think some of the issues raised against Erik Weilenberg’s Atheistic Moral Platonism would apply. Still, I will leave this as a potential, yet unlikely, option for the time being.

I think a more plausible and ultimately helpful account would be something like an Aristotelian-Thomist moderate realism. This is for two reasons. First, the notion of formal causes or substantial forms would present the necessary ‘natural kind’ or ‘species-essence’ by which to conceive of a species or class in a truth-testable way. Speciation events could be true in principle because there could presumably be a way, via genetics, cladistics, etc., to affirm distinct biological substances, A vs. B. Without this type of realism, what exactly would be correspondent to a speciation event? Species pliability is problematic for evolutionary realism, but nominalism (per above) is a bad option. The evolutionist should want to stay away from holding these things as nominal or mere constructs.

Secondly, the notion of Aristotelian final causes would provide additional lift. Intrinsic final causes, the inherent tendency of X to Y, would underpin the understanding of organisms to act in certain ways. The process of selection itself seems dependent upon this notion for coherence. In the absence of final causes, there would be no compelling reason to even rationalize observed regularity in nature at the fundamental level of physics and chemistry. At a higher level, species are intelligible insofar as they tend toward certain operations and actions. Species A tends toward a certain diet, reproductive cycle, migration pattern, and so forth. Too many aberrational observations in A leads us to re-think A, break out sub-variations within A, or draw other conclusions entirely. It is precisely due to final causes that A is analyzable for science.

I have tried to sketch a few reasons why the evolutionary realist must necessarily step into realism to preserve the truth value of his theory. Aristotelian realism presents the most attractive option, and perhaps the shortest move. Without formal and final causes, essences and goal-directedness, evolutionary theory can only turn to Platonism. There does not seem to be a good reason to force Platonism given the advantages of the Aristotelian apparatus. If evolutionary theory is anti-realist, it cannot be taken as a true or likely even a limiting account of natural history.

Following closely on the heels of these conclusions are deeper questions about natures/essences and final causes. Can we just stop there without asking more questions? Questions that perhaps go beyond the bounds of physical sciences? For Aristotle, the answer is that we cannot prevent further inquiry into the science of causes and being qua being, viz. metaphysics. Studying the physical sciences leads us to seek further knowledge. I think this is very exciting and shows the systematic compatibility of science and metaphysics. There are also theistic implications that come into the fold, which I will leave for a future post.

Evolutionary Science and the Existence of God

Arguments of the “evolution, therefore not-God” sort (pace E.O. Wilson, Robert Wright1 and 2, et. al.) are prevalent. Though these authors write at the popular level on the topic of theistic belief (among other things), what they advance are variations of Evolutionary Debunking Arguments (EDAs). There are many versions of EDAs across the spectrum of philosophy. These arguments typically impugn justification for affirming the truth of certain propositions, such as “there is such a being as God” or “objective moral values and duties exist,” and so forth.

EDAs seem to run hot and cold in the academic literature, and they are quite controversial. Alvin Plantinga delves deeply into this subject in his well-known book Where the Conflict Really Lies: Science, Religion, and Naturalism. Plantinga's primary focus is against naturalism, finding that it ultimately undermines what its proponent wants to show. I believe it is from Plantinga's work (even prior to the book cited above) that EDAs have become more prominent. Or, at least the question of evolutionary influence on beliefs has become a more widespread topic of discussion.

I find many problems with certain types of EDAs, some of which I will try to briefly sketch in this post. Here I will just cover EDAs as they relate to the question of God’s existence. In the future, I will try to address EDAs in ethics. My focus here is not on the science/theism discussion, as Plantinga and others have addressed.

To see some of the problems, we might break down the “EDA contra God,” as follows:

1. All human beliefs are genetically/evolutionarily caused.
2. Many humans believe in God.
3. That many humans believe in God is genetically/evolutionarily caused (from 1 & 2).
4. Any genetic/evolutionary factors causing human beliefs are (or can be in principle) ultimately explainable by evolutionary science.
5. That many humans believe in God is ultimately explainable by evolutionary science (from 3 & 4).

[Note that I am not attributing this exact argument to any particular person or work. This represents a synopsis and synthesis of the EDA contra the existence of God.]

The main implication, or outright obviousness, proponents find in the conclusion of this argument is that “there is such a being as God or something like God” or “God exists” is false. And by "God" I mean that as conceived and understood under the general guise of monotheism. Such propositions about God cannot be an expression of something “real” (or "extramental reality") because evolutionary forces explain the entirety of why we think it/say it. We do not think it because it is true in any sense of the term “true,” but because, for lack of a better term, our genes tell us to think or utter it. Since it is evolutionary influences on our biology that cause us to think God exists, God must not really exist, or so the argument seems to go. For, it is possible - or even likely - that in the future evolution will have rendered belief in God unnecessary or the genes that now cause us to think that God exists will no longer have such an effect, or the current evolutionary by-product that causes us to think God exists might be eliminated by selective pressures. 

Something interesting to consider is that this type of EDA centers on belief. In a philosophical sense, the most such an epistemologically centered argument can legitimately hope for is to undermine justification or warrant for holding a certain belief. But only the theist holding to certain epistemologies will face challenges on this front. This issue gets further tangled up in questions germane to the internalist/externalist debate. Unless a question-begging premise is inserted, it does not seem the theist is necessarily faced with an intractable problem, depending upon how they cash out justification or warrant. Further, one opting for a Thomistic direct-realism, as I do, would not necessarily have any epistemological problems to overcome (again, unless there was a question-begging premise).

It is also worth noting the challenge in moving from an epistemological claim to an ontological claim. Even if the theist concedes the argument without rebuttal, it could still be the case that God exists. “God exists” or “there is such a being as God” could well be true, but one might not be rational in holding that belief if the argument is successful. So, the argument does not ‘disprove God’ or anything of the sort. Rather, it casts aspersions on such belief at best.And the extent one thinks it possible to undermine or defeat belief or justifications for belief by such measures will largely be driven by the epistemology they hold.

What was presented above is a general formulation of the EDA, but I think it is representative. As of late, the EDA contra God has worked itself into popular literature, hence the authors I referenced above. I have found this line of thinking represented in many personal interactions, as well as online/social media. I think philosophers like Daniel Dennett and Alex Rosenberg espouse similar arguments in higher level writings, aimed at more interested laypersons and even some academics.

Looking at the argument as formulated, an obvious tension exists between (1) and (5). For, if (1) is true, then belief in evolutionary science is also genetically driven. (1) puts all beliefs on the same genetically/evolutionarily determined plane. Recall that the EDA contra God is that “God exists” or “there is such a being as God” is false (or probably false, etc.) because the utterance of the very sentence itself is an output of evolutionary genetics. Yet, the EDA proponent is probably unwilling to subject the proposition “evolutionary theory is true” to the same evolutionary caused belief 'defeater'. If all beliefs are genetic outputs from natural and environmental inputs, then so is the belief in evolution. Plantinga and others have made this (or a very similar) point at length. The only way out for the EDA proponent seems to be special pleading, whereby evolutionary science, and maybe some other scientific disciplines as well, is excluded from evolutionarily caused beliefs.

The EDA contra God presents itself as a meta issue in many respects. It dismisses any arguments for God by calling into question the very offering of argument. In so doing, the EDA proponent operates from a privileged place. By this, I mean the EDA proponent assumes a vantage point by which they can make their argument with impunity. They assume the high ground and become the sole gatekeeper of truth. They set the very framework and rules by which any belief or proposition should be accepted. If it comports with evolutionary science, then accept it; if it does not comport, reject it. But why should anyone accept this? Such a view seems quite unscientific.  In any case, I am unconvinced that we have any good reasons to make evolutionary science the absolute yardstick, and a malleable yardstick it would be. Note I am not necessarily calling into question evolutionary science itself. Instead, I am questioning what appears to be an abuse of it.

There is another major problem with the EDA contra God. The argument implies that other scientific fields, especially physics and cosmology, are lesser than evolutionary science. Evolutionary science must govern any beliefs whatsoever resulting from scientific inquiry. But evolution itself seems to rest upon at least sciences like physics, geology, and chemistry, for without these, evolutionary theory could not well get off the ground. Further, the cosmologist studying the early universe might consider the anthropic principle and conclude that something outside the universe brought the universe (or multiverse, etc.) into existence or to have arranged the universe in such a specific way. Such a scientist perhaps originally begins research from a state of theistic agnosticism or even atheism and then, after many years of study concludes that the best explanation for the fine-tuning of the universe is that God (or something very much like God) exists. Now, in this case, the EDA proponent would be required to inform the cosmologist that his/her conclusion was not in fact based on their scientific research, but instead is the output of a genetic trait. Bubbling under the subconscious surface the entire time was this belief in God, ready to spring forth given enough intellectual rationalization or other (genetically/evolutionarily explainable) event. 

Per the EDA contra God, even the cosmologist in our example cannot in principle give a rational conclusion at the end of a reasoning chain. Instead, he/she must be told that, while his/her research might be good in all other facets, his/her conclusion was hardwired by billions of years of evolutionary history. Note that the cosmologist’s conclusions about the anthropic principle itself, and non-theistic inferences drawn therefrom, are not genetically predisposed to pop out. Just the “God exists” inference cannot at all be based on rigorous scientific inquiry, but reducibly based on factors that were either evolutionarily advantageous or by-products of the evolutionary process. The reasonable cosmologist would likely be quite indignant at such claims against their research and inference mechanisms. I would also submit that if the cosmologist in this example made the conclusion "God does not exist" after his long and labored study, the EDA proponent would no doubt applaud him for such a good and sound scientific conclusion. 

Another major problem with the EDA contra God is that it seems to commit a classic genetic fallacy. At least in terms of the ontological conclusion typically advanced. But why should we think that “God exists” is false because evolutionary forces brought this belief about? Unless the EDA proponent wishes to throw the truth value of all evolutionarily driven beliefs under the bus, the possibility must remain open that “God exists” is true. We should observe that EDAs tending toward skepticism instead will provide no safe quarter for the EDA proponent. This is because the belief disposition delivered by evolution must be applied universally to all beliefs on pain of special pleading/arbitrariness.

My conjecture on these arguments is that EDA proponents start with a metaphysical conclusion and then seek to justify it by other means. I cannot see any other reason one would pursue this line of argumentation. It is either this or an a priori commitment to scientism. The EDA proponent seems to ask themselves, “given that God does not exist, why do so many people believe in God?” Or, perhaps more likely, "given that I and many others do not believe in God, why is it that so many other people do?" From here, they naturally look to the sciences for an explanation. And within evolutionary science/genetics, they find solace in a wholesale explanatory mechanism. Since, on their view, there is really nothing about human existence that is not explainable by evolutionary science, then belief in God must fall exclusively into this bucket.

Much more could be said on this subject, and I intend to write more in the future. It should suffice for now to say that EDAs contra God suffer from many debilitating problems. But they should be taken seriously if for no other reason than the influence they have in popular and (occasionally) academic culture.