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#707 Plantinga’s Evolutionary Argument against Naturalism

November 08, 2020
Q

What are the problems with naturalism? On the surface naturalism seems straightforward. It’s a materialist view that asserts the natural world is all there is. It could be conceived as a polemical stance against the existence of gods, sprites, demons, and magic. In the end, however, it boils down to a variation of WYSIWYG: what we see is what we get. There’s natural stuff, and physical laws, and everything that concerns us boils down to these two.

Yet some talk as though naturalism is not only wrong or problematic, but that it’s essentially been shown incoherent and it’s a gateway worldview to utter despair and global political tyranny can you explain how naturalism does any of these things? This is a quote straight from you.

"Moreover, naturalism faces severe problems of its own. The philosopher Alvin Plantinga has argued persuasively that naturalism cannot even be rationally affirmed. For if naturalism was true, the probability that our cognitive faculties would be reliable is pretty low. For those faculties have been shaped by a process of natural selection which does not select for truth but merely for survival. There are many ways in which an organism could survive without its beliefs’ being true. Hence, if naturalism were true, we could not have any confidence that our beliefs are true, including the belief in naturalism itself! Thus, naturalism seems to have a built-in defeater that renders it incapable of being rationally affirmed."

This “severe problem” seems a trifle and perhaps beside the point. First of all, naturalism is affirmed by reason and also by empirical data and method. The basis for naturalism extends beyond a series of premises and conclusions that exist only in a philosophical treatise. Second, whether naturalism can be rationally affirmed hardly seems relevant; what’s important about naturalism is its empirical basis. We have empirical basis for naturalism. Do proponents of opposing views have empirical underpinnings for their views? Again, I mean it: what is the data in support of these non-naturalist views? Third, maybe I’m reading into your remarks but it sure seems like you are evaluating naturalism based on your desire that a different model be true. In other words, you come across to me as emotionally invested in a viewpoint besides naturalism.

So, I wonder if there’s more to the critique of naturalism than I know. Anyone have solid arguments that are part of this critique?

Anonymous

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Dr. craig’s response


A

On the surface, naturalism seems like a perfectly plausible, unproblematic view. “What you see is what you get!” What could be simpler than that? But philosophers know that naturalism is a controversial world view, which is difficult to articulate, much less to defend. Although I don’t want to dwell on this, your own formulation of naturalism is incoherent: “It’s a materialist view that asserts the natural world is all there is. . . . There’s natural stuff, and physical laws, and everything that concerns us boils down to these two.” The problem is that physical laws, being mathematical entities, are not material but abstract. So your view isn’t materialistic after all, and the natural world is not all there is: you’ve got a bifurcated reality composed of natural stuff and mathematical laws, a bifurcation which will prove to be problematic in its own right. In this QoW let’s focus on the issues that you raise.

To begin at the end, I freely admit that I’m “emotionally invested” in theism. How could I not be, since God has changed my life? Naturalists may be similarly emotionally invested in naturalism. Thomas Nagel has famously said, “I want atheism to be true and I am made uneasy by the fact that some of the most intelligent and well-informed people I know are religious believers. . . .  I hope there is no God! I don’t want there to be a God; I don’t want the universe to be like that.”[1] Recognizing one’s emotional investments rather than denying them is the first step toward not being misled by them and being able to assess arguments objectively. Your own emotional investment in naturalism is obvious from your blasé attitude toward Plantinga’s argument that naturalism cannot be rationally affirmed. Anybody who dismisses an argument which shows a view to be “incapable of being rationally affirmed” as a “trifle” and “beside the point” is either uncomprehending or blinded by prejudice.

Is naturalism “a gateway worldview to utter despair”? Many naturalists, such as Nietzsche, Russell, and Sartre, to name some of the most famous, have thought so. I think that they are right. The reason is that given naturalism, it’s very difficult to show in the absence of God that objective meaning, value, and purpose in life exist.[2] Hence, the realization that atheism is true leads to despair, at least for a reflective person, since it’s impossible to live happily and consistently as though one’s life were meaningless, valueless, and purposeless.

Your breezy dismissal of Plantinga’s Evolutionary Argument against Naturalism is way too quick. Here a dose of intellectual humility is in order. An argument put forward and refined by a genius like Plantinga and fervently debated by philosophers in professional journals is hardly a trifle or beside the point. If you think so, then you should immediately suspect that you have misunderstood the argument. Plantinga argues that naturalism is self-defeating because if our cognitive faculties have evolved by naturalistic processes, they are aimed, not at truth, but at survival, and so cannot be relied on to produce true beliefs.  Since on materialism our mental states have absolutely no effect on our brain states, the content of our beliefs is irrelevant to our survivability. But if we cannot rely on our cognitive faculties to produce true beliefs, then the belief in naturalism is itself undermined, since it has been produced by those very cognitive faculties. 

Plantinga’s argument can be simply formulated as follows:[3]

1. The probability that our cognitive faculties are reliable, given naturalism and evolution, is low. 


2. If someone believes in naturalism and evolution and sees that, therefore, the probability of his cognitive faculties’ being reliable is low, then he has a defeater for the belief that his cognitive faculties are reliable. 


3.  If someone has a defeater for the belief that his cognitive faculties are reliable, then he has a defeater for any belief produced by his cognitive faculties (including his belief in naturalism and evolution). 


4.  Therefore, if someone believes in naturalism and evolution and sees that, therefore, the probability of his cognitive faculties’ being reliable is low, then he has a defeater for his belief in naturalism and evolution.

Conclusion: Naturalism and evolution cannot be rationally accepted.

This argument, if sound, is devastating. It shows that no rational person can be a naturalist.

Now how do you respond to this argument? Consider your three points:

1. Naturalism is affirmed by reason and also by empirical data and method. I hope you can see that Plantinga’s argument has undermined this claim; indeed, the whole point of the argument is to show that reason and evidence fail to support naturalism because naturalism undermines our use of reason and evidence. It shows that our cognitive faculties, given naturalism, cannot be trusted.

2. Whether naturalism can be rationally affirmed hardly seems relevant; what’s important about naturalism is its empirical basis. This response reveals that you have completely misunderstood the argument. If naturalism cannot be rationally affirmed, then there is no empirical basis for naturalism. For if our cognitive faculties are unreliable, then our perceptions of the external world cannot be trusted and the empirical basis for naturalism is undermined.

You ask, “Do proponents of opposing views have empirical underpinnings for their views?” Yes. I invite you to consider the many arguments for the existence of God that I have defended, which are nicely summarized in brief animated videos to be found on our home page. Here are some of the premisses that enjoy empirical support:

Every contingent thing has a cause of its existence.

The universe began to exist.

The fine-tuning of the universe is not due to physical necessity or chance.

Physical phenomena are describable with an amazing accuracy by mathematical laws.

There are three established facts about the fate of Jesus of Nazareth: his empty tomb, his post-mortem appearances, and the belief of his original disciples that God raised him from the dead.

Other premisses enjoy, if not empirical support of the five senses, then experiential support:

Objective moral values and duties do exist.

It’s possible that a maximally great being exists.

The argument from the applicability of mathematics is especially relevant to you. I mentioned above your bifurcated view of the world, comprising a material realm of physical objects and an abstract realm of mathematical laws. One of the deepest problems of naturalism is to explain how these two independent realms of reality relate and come into contact with each other. Theism offers a ready solution to this problem. You may want to watch my dialogue on this question with the Nobel Prize winning physicist, Sir Roger Penrose.

These are just a few of the problems facing naturalism. For more, you can dig into my and J.P. Moreland’s Naturalism: A Critical Analysis, Routledge Studies in Twentieth-Century Philosophy (London:  Routledge, 2000).


[1] Thomas Nagel, The Last Word (Oxford: Oxford University Press, 1997).

[2] I’ve argued this in my Reasonable Faith, 3rd ed. rev. (Wheaton, Ill.: Crossway, 2008), chap 2.

[3] Following Alvin Plantinga, Where the Conflict Really Lies: Science, Religion, and Naturalism (Oxford: Oxford University Press, 2011), pp. 344-5.

- William Lane Craig