NOTE: This essay was written by Josh for Atheism is Dead (True Freethinker’s predecessor).
This will probably be an ongoing discussion here at AID as long as I’m around for the simple fact that I believe it is such a crafty, persuasive and sound argument. Once understood properly, there are significant problems that the naturalist will have to encounter. While this particular post uses Plantinga almost exclusively, there are related issues and arguments that will undoubtedly crop up in future explorations that will deviate from Plantingian waters.
With that in mind, let me offer a few words of advice for those of you that are encountering the argument for the first time. Some of these sound rather silly, but all of these have been lobbed against my presentation of the argument, and some I’ve seen already tossed at my mini-explanations on this blog.
First of all, what is R? According to Plantinga, it is the proposition that “our cognitive faculties are reliable.” This does not mean that we are always rational, or always produce true beliefs or any such related idea, but rather that our cognitive equipment provides enough accurate beliefs such that we are warranted, in general, to trust our cognitive equipment.
So then, R will not be attacked by anyone who wishes to debate this argument, as R is simply an assumption of every person (especially people that like to debate things like the existence of God). Without R, there is no justification for holding that ANY belief produced by our cognitive faculties (which is all our beliefs) which would include our belief that God does or does not exist, naturalism is true, evolution is true or I am reading a particularly wonderful entry on Atheism is Dead. Hopefully that is that.
2) The nature of N.
N is fairly simple to understand but possibly hard to pin down in print. N stands for “naturalism”, and the hope is that N here is broad enough to cover whatever non-theistic position one might hold. Naturalism does not entail that everything that exists is physical, even though most naturalist might hold that. For example, a thinker I’d consider a naturalist but not a physicalist is W.V.O. Quine. Quine believed that numbers were abstract objects that had a kind of real, non-physical existence. However, he was most certainly would scoff at the idea of a transcendent Creator-God. Minimally, naturalism entails that theism is false. But what is it about theism that naturalists spurn? Let me offer the following definition of Naturalism (N in Plantinga’s argument) tailored specifically for this argument:
N) The world, including our cognitive faculties, were designed by fundamentally non-teleological forces.
Alright, a few words of explanation here. What I am really driving at is the naturalists belief that the causes of our belief-creating-faculties were not designed with some far-reaching goal by any kind of intelligence. Don’t let “design” trip you up, as I am using it in a neutral kind of way (much like Dennett does). In other words, there isn’t some kind of agent that directed the universe to create and design minds that have the overriding purpose of producing true beliefs. I don’t know of any self-respecting naturalist that would reject my charitable definition of N.
3) The nature of E.
I don’t think that this one is quite important, though I’ve been complained to over the years for not taking the time to really flesh out a sophisticated account of E. What E stands for is simple- our modern account of evolution. I realize that there are various accounts of evolution, and that most of it is an in-house debate. Some groups place enormous weight on natural selection, while others lessen natural selection’s explanatory power in favor of other factors (see genetic drift). To be honest, I haven’t seen how the various interpretations of E have an impact on the argument, and for the most part a discussion on it serves as a distraction at best (though quite an interesting one). Besides all of that, the work of Stephen Stich (who is no friend to the argument) has preemptively answered all of the possible distinctives E could possibly harbor.
*If you are interested in this part of the debate, I kindly redirect to Stich’s own work. If you have access to JSTOR, I recommend the precis of his book (otherwise, this link ought to work) If you are really brave, you can pick up the book which contains his work on the topic of evolution and rationality here. I’m quite familiar with the work itself as I presented a 30 page paper on his book less than a year ago for a local philosophy and science group. I would love to talk about this some other time, but unless the comments are tangentially related to Plantinga’s argument, I’d ask that y’all hold off for now.
With that out of the way, we can proceed to the meat of the argument. Here is Plantinga’s formula:
P(R/N&E)
This reads something like “The probability of our cognitive faculties is reliable given the conjunction of naturalism and evolution.” Now, naturalists are going to attempt to explain using the resources available to them. Per our definition of N, we do not allow things like God into the mix. Rather, the naturalist will opt for another mechanical, non-teleological explanation for R. The following sentences are a token of such an explanation:
Naturalist: The reason our cognitive faculties are reliable is because of our evolutionary history. Creatures that had reliable cognitive faculties tended to survive better than those with unreliable cognitive faculties.
I assume that this would be the most widely used explanation of why we believe R is a justified belief. It is Plantinga’s opinion that this explanation is entirely faulty. The naturalist must try to show how there is a natural connection between beliefs (mental content as opposed to merely cognitive structure) and action, and that the beliefs must be true in order to aid in survival. How is it that evolution would promise us true beliefs? Doesn’t evolution give us reason to believe that we will be survivors of some sort, regardless of the verisimilitudinous nature of our beliefs? Consider the following concession by Patricia Churchland:
“Boiled down to the essentials, a nervous system enables the organism to succeed in the four F’s: feeding, fleeing, fighting and reproducing. The principle chore of the nervous systems is to get the body parts where they should be in order that the organism may survive…Improvements in the sensorimotor control confer an evolutionary advantage: a fancier style of representing is advantageous so long as it is geared to the organism’s way of life and enhances the organism’s chances of survival. Truth, whatever that is, definitely takes the hindmost.
Patricia Churchland, “Epistemology in the Age of Neuroscience,” Journal of Philosophy 84 (October 1987): 548.
Churchland’s driving intuition is that adaptive behavior is king, and “true” beliefs are only desirable in a conventional, pragmatic sense, if they are desirable at all. Not all naturalists would just bite the bullet like this, however. Perhaps the naturalist would say that say something like this:
1) Evolution produces agents that tend to survive.2) Agents that tend to survive tend to have true beliefs.
.: Evolution produces agents that tend to have true beliefs.
(1) is not controversial (perhaps it is merely tautologous). What reasons do have to think that (2) is true? Mightn’t a creature have largely false beliefs and get along just fine? We have a few options here. Either:
A) Our behavior is determined by the structure of our beliefs (See here).
B) Our behavior is determined by the content of our beliefs.
If (A) is correct, then having beliefs is what is important rather than what those specific beliefs are. The color of a basketball does not matter as long as the basketball is present. Likewise, having a neuronal event takes care of the behavior of the creature without reference to to actual content of the belief. To explain this a bit more, let’s say that neuronal event N is sufficient for adaptive behavior B. Would it then matter what attending thoughts are present with N? Not in the least. It is clear, then, that if (A) is true, premise (2) from above is false (unless we just get lucky and happen to have true beliefs correspond with each neuronal event). It seems to me that this is the most likely situation given naturalism, as it refers to physical happenings for an account of behavior rather than mental ones. (As Plantinga puts it, our beliefs are invisible to natural selection.) It is also the logical position of anyone who accepts the view that our cognitive faculties weren’t “designed” to confer true beliefs; what reasons could one provide for a necessary link between beliefs and behavior? Surely it isn’t logically impossible that false beliefs produce adaptive behavior. Why then posit such a strong connection between the two? It has the look of an ad hoc escape route written all over it. But even if (A) is false, (B) does not give us any more of a rationale for accepting the truth of (2).
Let’s look at option (B) again:
Our behavior is determined by the content of our beliefs.
Granting this, does it follow that it is more adaptive to have true beliefs rather than false ones? Plantinga lists a number of beliefs that he believes are survival-conducive yet as false as can be:
*Everything is conscious*God exists (Even some atheists admit that belief in God, while false, has been adaptive)*Paul believes that petting tigers is the best way to survive, but he also believes that running away from tigers as fast as he can is the best way to pet a tiger.
*Paul enjoys the idea of being eaten by a tiger, but always flees in order to find a better prospect.
The point being, their are many appropriate behaviors that could possibly follow from a number of false beliefs. This means that (2) is false as it stands and furthermore, P(R/N&E) is low.
What follows from P(R/N&E) being low? It means that evolution does not suffice as an explanation of R, and that naturalists will have to supplement their explanation of R with something that provides a reason to think that R is true. Theism provides that supplement.