A Conflict Between Naturalism and Science?

Around 5 years ago I was browsing the philosophy shelf at Barnes and Noble when I came across a book with one of the most compelling thesis I have ever come across. The book is called Where the Conflict Really Lies: Science, Religion, and Naturalism by philosopher Alvin Plantinga.

Plantinga argues that while there are apparent conflicts between science and theism, the two are actually fundamentally compatible. And, while science and naturalism are apparently compatible, the two actually have a deep conflict. Given that most in our culture believes the exact opposite, this is a startling thesis.

We first need to define Naturalism and distinguish it from science. Naturalism is the belief that nature is all there is that, at base, there is no purpose or mind directing the universe or humanity. Naturalism is a philosophy, a metaphysic, a worldview. Naturalism is not the same thing as science, though the two are often confused by Christians and Atheists alike.

Science, on the other hand, is the method by which we understand the physical world around us. Science has a deep compatibility with Christianity – though several apparent conflicts. (Plantinga specifically addresses miracles and evolution.)

Conflict and compatibility

The deep compatibility between science and Christianity comes from the nature of God and the nature of humanity. God, in Christianity, reveals Himself in nature, in the physical world. And, He has made us humans in such a way that we can understand that same physical world. Because God is a God of order, the physical world is ordered and subject to rationale inquiry. And, because humans are created in God’s image, we have the capacity to reason, use language, and come up with theories for how things are and how they came to be. Our reasoning, language, and theories may be flawed, but the capacities which we use are generally reliable because they are God-given.

But, whereas there is a deep compatibility between Christianity and science, there is a deep conflict between the pseudo-religion of naturalism and science. What does he mean? Plantinga gives a strong and weak version of his argument. The strong version of his argument, he argues, gives a “defeater” for the naturalist, and here he spends most of his time. The weaker version of the argument doesn’t necessarily provide a “defeater” but for me it is more comprehensible and thus, for now, more compelling.

The reliability of our beliefs from naturalism

Plantinga argues that, if both naturalism and evolution are true, the probability of the content of our beliefs being true, is low. But, if it’s unlikely that our beliefs are true, then we have no reason to have confidence in any of our beliefs, including our beliefs about naturalism and evolution. Thus, the beliefs that naturalism and evolution are true forms a defeater for the argument “naturalism and evolution are true”. And, in fact, it forms a defeater for any other scientific claim.

But why does Plantinga believe that it is improbable that the content of our beliefs are true given unguided naturalistic evolution? The answer lies in the nature of evolution and the materialistic view of neurophysics.

Unguided evolution and neurophysics

First, unguided evolution: The theory of evolution argues that life evolves through natural selection in order to reproduce itself. Natural selection favors whatever “gets the body parts in the right place” in order to survive, and survive long enough to reproduce, thus passing along the genetic code. That is, evolution through natural selection is blind and agnostic when it comes to truth. “Truth” only comes in insofar as it leads to survival and reproduction. If evolution can produce a desired behavior with a lie, it is not the worse for wear.

Second, neurophysics: The brain works through collections of neurons and connections between those neurons. Let’s call a particular collection of neurons firing in a particular way “N”. N has two properties: Neuro-physiological properties (NP Properties) and content. The NP properties are the physical properties which make up the mental state. The content is the belief. For example, the thought “naturalism is overrated” is the belief or content. It is true to the extent that, in the real world, naturalism is overrated. On a naturalistic worldview, the content arises from the collection of neurons, N, firing in a specific way.

Beliefs and Indicators

Here Plantinga makes a crucial distinction between beliefs (the “content” that arises from N) and the indicators that lead to the response which the NP properties produce. That chemical/physical response is what is selected for during the evolutionary process. Whether or not the belief is true doesn’t matter. That the zebra runs away from the lion matters. The content of the Zebra’s belief isn’t. The Zebra’s belief could be a lie. It wouldn’t matter, so long as the Zebra responds in a way that it escapes danger.

If this seems dubious to you, it did to me at first, too. Two reasons spring to mind. First, I implicitly trust that my beliefs are generally reliable. It’s hard to imagine a world in which they are not. But, the question isn’t whether I think my beliefs are reliable, but whether under naturalism I am warranted to think they are.

Second, we often think about our cognitive processes in the following way: The NP properties of the neurons N produces a belief. That belief produces the action. That belief then needs to be reliable for the action to lead to survival and reproduction. But, says Plantinga, that’s not how it works. Again, from a naturalistic/materialistic worldview it’s the NP properties by themselves which produce the action, so the truth of the belief, it’s relevance to the real world, is suspect.

Now, if the truth of beliefs is not what naturalistic evolution selects us for, then what is the probability that our beliefs are reliable? Again, you may think your beliefs are reliable, but the question is this: Given naturalistic evolution, what is the probability of our beliefs being reliable? They’re low.

But, if you doubt whether or not your beliefs are reliable, then you should doubt your belief about naturalism is reliable and you should also doubt your beliefs about science. Thus, belief in naturalism and evolution is self-defeating, since it undermines the reliability of our beliefs in general.

Now, there are a few key steps in this argument that I admit I do not fully comprehend, especially the relationships between the NP properties, actions, and the content of our belief. That makes this strong version of the argument interesting to me, but not quite as compelling as it would be if I understood it more clearly. Perhaps if you read that chapter in his book you’ll be able to enlighten me further.

How sociology helped me see the conflict more clearly

There’s a weaker version of the argument, though, which says something similar, and which is newly compelling to me. After I read this from Plantinga five-ish years ago I set it aside. It gathered dust on a shelf in my brain until I started reading a lot of sociology books. There I discovered something interesting: Naturalistic sociologists are fond of pointing out how unreliable our reasoning actually is. 

Case in point: Future Babble by Dan Gardner. The thesis of this book is that people – especially experts – are terrible at making predictions about the future because humans weren’t designed through the evolutionary process to do this. In fact, Gardner gives a whole list of instances where we shouldn’t trust our beliefs because of evolutionary embedded functions. We’re not, on Gardner’s account, fitted for this sort of predictive and abstract thought. As I read, though, I couldn’t help be think: Gardner is undermining his own argument! If I shouldn’t trust experts, why should I trust Gardner? If I couldn’t trust my own faculties, why should I trust my own interpretation of his book?

Gardner’s is an exceptional case, but it’s far from the only time I’ve noticed this. There seems to be a growing consensus in the secular books I’m reading that evolution has not produced people who are terribly good at discerning truth. In most cases, it’s just not relevant to survival! But, again, if the naturalist recognizes that he is not equipped to discern truth, why should he accept his truth about such questions as: Does God exist?

The compelling argument to me then, is this: Perhaps there are some beliefs which we would expect evolution to produce a strong correspondence between that belief in reality. But there are other beliefs, those most associated with abstract and technical thought, which naturalistic evolution would not design us for. Or rather, for which unguided evolution would be entirely agnostic. Philosophy, mathematics, the scientific method, etc. would have had no bearing on whether or not a member of the species could survive and reproduce. In fact, today, knowledge of some of these areas might be a detriment to reproduction (“What does an engineer use for birth control? his personality”).

Closer correspondence with reality

In other words, give unguided evolution, it seems we shouldn’t trust our beliefs to tell us the truth unless they are specifically associated with those things which evolution would select. “Naturalism is true” is one of those claims which we shouldn’t trust, given our belief in naturalism. Hence, it defeats itself.

But, if God exists and created us then we would expect him to enable us survive, reproduce, and be able to think rationally about philosophy, science, religion, morality, mathematics, and all sorts of other abstract things which have nothing to do with survival and reproduction. And, of course, we do think about all those sorts of things and, indeed, our beliefs do seem to be at least somewhat reliable – though certainly far from infallible.

Thus, once again, I see the rationality of belief in God for, once again, it provides a broader explanatory scope of the world  I live in than does atheism.