In Chapter 10 of “Where the Conflict Really Lies,” Alvin Plantinga uses his Evolutionary Argument Against Naturalism to argue that science and naturalism are at odds, or discord. The core of the argument is this: if naturalism and evolution are true, then our minds have developed to value adaptive thinking, not necessarily true thinking. Therefore if you believe naturalism and evolution, you have no reason to believe your thinking is accurate. On the other hand, if you believe we are made in the image of god, you have a strong case for believing we can understand truth.
Books have been written about this particular argument of his, including “Naturalism Defeated?”, an anthology of criticisms of this theory. My sources for authors not hyperlinked can be found in that book. I’ve expanded my reading far beyond this chapter in the book in order to get a better bead on the argumentation. I will combine my own responses with those from others that I feel make important criticisms. I don’t think that his argument stands.
Evan Fales points out that Plantinga’s argument is unique to Judeo-Christian belief in mankind being created in the image of god. Furthermore, this conception rests upon a specific interpretation of Gen 1:26-27, one that holds that the characteristics of the human mind were given as a matter of man being made in the image of god, and makes the assumption that being made in this image actually imparts reliability. The problem of evil (we don’t really understand God’s purposes) and the Christian view of man’s sin (we are fallen and blinded by sin) very strongly argue against the reliability of our mental processes. The Judeo-Christian god tells us that his thoughts are high and far above our thoughts. Scripture tells us not to rely on our own insight, and that our hearts are deceitful. The Judeo-Christian representation of man’s mental capacity is pessimistic at best. Given the testimony of the rest of scripture, interpreting it to give mankind a reliable mind is a bit inconsistent.
What is ironic is that Plantinga would deny a literal reading of Genesis 1 anyway! This all seems very shaky ground to build an argument like this on. As we have seen throughout this book, when Plantinga says “theism,” he really means “Christian theism,” but he never stops to defend Christian theism, and specifically his understanding of it, from other theisms, much less define it. I think if he admitted he was arguing for Christian theism and was forced to defend these ideas on the basis of Christian doctrine, he would be in trouble.
Another great point is made in Richard Smith’s review of Plantinga’s book. If Plantinga is right and the accuracy of our thoughts depends on god creating the human mind, we would expect him to get it right. However we see in the physical world that god doesn’t get it right. Smith offers the examples of women dying in childbirth and children dying of fatal diseases. If our physical being is so imperfect then what gives us reason to expect that our cognitive faculties are trustworthy? So Plantinga’s alternative is unworkable and no alternative at all.
Under a naturalism+evolution framework, we can easily explain why humans hold false beliefs. If our mental faculties were an imprint of the image of god, how does he explain why humans hold false beliefs? Why is our tendency to hold false beliefs worse under naturalism+evolution than theism+evolution?
Natural selection isn’t about accuracy, but about functional sufficiency. I can be a terrible shot, but bring down a deer and have dinner if I happen to shoot it in such a way that it can’t run far. I’ve survived without being accurate. We may wince at the medical remedies of, say, the 18th century. But those remedies were functionally sufficient in that they had some success in promoting human life in certain cases. The same goes for any modern invention or theory that has functional application. We understand the forces of the atom enough to produce excess energy from fission, but not accurately enough to produce excess energy from fusion.
The same kinds of thinking we use to develop such theories and inventions as prove of benefit to us are the same kinds of thinking we use to arrive at naturalism. We see the world is messy and unoptimized in a way that does not comport with intentional design. Vestigial organs, vicious predation, traumatic insemination, childhood death, and the all too well known inefficiencies of the human body, to name just a few, do not bear the mark of a designer, but of an unguided process that allowed anybody to survive, if only they could.
A reading of the responses of Jerry Fodor and William Ramsey to Plantinga, together, suggest a that it is unlikely that false beliefs result in adaptive behavior more often than true beliefs. (It is also reasonable to assume that a mind uninterested in truth per se would happen upon true beliefs from time to time.) Therefore natural selection, while allowing for the potential adaptiveness of false beliefs, would favor true beliefs over time. Conversely, this shows that false beliefs are not systematically adaptive over the long run, even if they happen to be adaptive in a given instance. Therefore, naturalism+evolution would tend to produce reliable minds that operate more on true beliefs than false.
(Let’s not forget that while natural selection obviously perpetuates adaptive traits, it also perpetuates other traits that happen to co-exist in the same being, whether or not they are related. So we would not expect natural selection to result in the perfection of mankind’s thinking, anymore than natural selection would result in a perfect body.)
Plantinga tries to answer this objection in section 5C of chapter 10. To show how he doesn’t succeed, it is important to follow him carefully. Specifically, in the section dealing with reductive materialism (5B), he recognizes that under reductive materialism, neuro(physio)logical phenomena (NP) and content/belief are the same (“...NP properties also constitute the property of having such and such content…” p.334). Then he says “if these properties had constituted different content” (p. 335) without explaining why the same NP properties, under the reductive materialist conception, would result in different content. The concept of reductive materialism is that you CAN reduce content to NP properties. This has the effect that NP properties ARE content. Much of this chapter involves Plantinga trying to drive a wedge between NP properties and content, but you can’t do that with reductive materialism, and in fact he doesn’t even try, except for the above brief hypothetical, which doesn’t make any sense in the context.
Reviewing the section on reductive materialism with an understanding that Plantinga at least implicitly realizes that NP properties and belief content are the same under this conception, we find that his argument against reductive materialism is primarily that the NP/belief structures do not have to be true to be adaptive. He does say that they MAY be true within a naturalist conception (“...if this content, this proposition, were true; it could just as well be false” p.334). He implies that, given naturalism+evolution, truth and error would exist. In fact nowhere in his argumentation does he claim otherwise. This is important because if truth exists, then truth is an accurate representation of reality. Therefore we return to our argument that although false beliefs can be adaptive, true beliefs would be more likely to be adaptive, and thus mental processes leading to true beliefs would tend to be favored by natural selection.
It is important to lay out that there is no wedge between NP properties and beliefs under reductive materialism because his objection in section 5C to our argument tries to insert the wedge yet again. Specifically, when he says that the argument is irrelevant because it doesn’t account for how things would be under a naturalism+evolution conception, he is arguing that under naturalism+evolution, NP and belief content are unrelated. But as we see, he has no good reason to argue that, especially if we hold to reductive materialism. Richard Smith argues in his review:
“...we developed multiple levels of simple and complex representations, of the internal world, of the external world, of possible outcomes and possible threats, of the past, and of possible futures, all interlocking in fantastically complex ways. This is what humans are best at. It's how we overcame so many obstacles and learned so many problem-solving survival skills.
“These representations are what the neurophysiological structures encode. And a reasonable idea is that their activation and processing constitute our thoughts as we experience them from the inside of the processing activity. There is simply no evidence or reason to postulate that these structures also encode content confusingly different from what they have so painstakingly encoded in the first place.”
Man’s physical survival involves a response to pain. Sometimes that pain is psychological in nature, which is to say that a specific negative mental state induces an attempt to correct it. Mankind at a very early stage would be most discomfited hearing a growling predator and not seeing it. Humans who could theorize their way out of such a situation would have a significant survival advantage. This developed into a generalized discomfort with missing or conflicting information. From this evolutionary tendency spring all manner of thought and theory (including religion and philosophy) as mankind variously encounters cognitive holes or dissonance. There is no good reason to suppose that these theories are, generally speaking, any less accurate (or representative of reality) with respect to their evidence than the theory that a predator is behind a rock, given that the same kind of mental activity is involved in interpreting the evidence. These higher theories are simply derivatives of the same types of thought processes.
This is true because, as Jerry Fodor points out, the action of natural selection in relation to mental fitness is centered on mental processes, not knowledge. A child may be born with high intelligence from his parents, but must still go to school to learn. To the extent that these mental processes produce more truth, as I argued prior, they have a better shot at promoting survival than mental processes that produce more error.
Some observers of Plantinga’s argument have noted that what he is really arguing against is philosophical naturalism, not methodological naturalism. Which is to say that science approaches the world with a naturalist methodology but does not make naturalist philosophical claims. Very well; however, it should be pointed out that what has been proven by modern science via methodological naturalism is generally accepted as true. How is it that the assumption of falsity (naturalism+evolution), if it is false, produces truth on such a consistent basis? (This is why some less charitable individuals have suggested that creationists give up the conveniences of modern life, if they don’t agree with the science that made them possible. Ostensibly they might now feel justified in extending this suggestion to Plantinga and those who agree with him.)
In my look at Chapter 9 we saw that the activity of the universe after the big bang created our universe with laws that were frozen shortly after, making the laws of the universe “accidental truths,” over against the necessitarianism advocated by Plantinga. If we consider multiple universes, each with their own big bang, each with their own laws of physics, we will not assume that truth in one universe is truth in another. Truth is dependant upon the state of universe one finds themselves in. It is necessarily incumbent upon the inhabitants of any given universe to discover these “accidental truths” on their own. It cannot be any other way.
So we see he must defend necessitarianism to defend his argument against evolution+naturalism, but our current knowledge of physics very much calls necessitarianism into question.