In Christian theologian Alvin Plantinga's book Warrant and Proper Function, Plantinga argues that, if both:
(N) naturalism – the view that there are no supernatural beings
(E) evolution - current evolutionary doctrine
are true, then the probability that:
(R) our cognitive faculties are reliable and produce mostly true beliefs must be either low or inscrutable.
Plantinga claims that this argument gives anyone who accepts N&E with a undefeatable defeater for any belief produced by those faculties, including N&E itself. Hence, N&E has been shown to be self-defeating (this is his Evolutionary argument against naturalism).
Basically, he is saying that "the combination of evolutionary theory and naturalism is self-defeating on the basis of the claim that if both evolution and naturalism are true, then the probability of having reliable cognitive facilities is low."
Now I am not going to criticize Plantinga's skills of philosophy, but it seems to me he actually hasn't thought about the ramifications of the claim.
If no cognitive judgments can be made, then rationality, is an illusion. We only think we are being rational, but in reality, our ability to make a rational, cognitive, decision would exhibit the same probability as a coin toss.
I offer an extremely easy to do scientific experiment which would show that Plantinga's theory is, in truth, a non-issue. It's basically a non-sequitur, and here's why.
Let's test the theory. We shall use a coin. We will give a control group certain problems to solve, while another group will be given the same problems. These problems will require using the cognitive function of the brain and thinking rationally to solve. While the other group will be attempting to answering the same problems based on random coin tosses.
If we see that the ratio of cognitive based problem solvers happen to provide the correct answer, and solve more problems, more often than the coin tossing based problem solvers then we can safely say cognitive function exists--regardless of whether naturalism and evolution both being true makes the probability of cognitive function low. Indeed, having tested the ration of random coin tosses with the ability to rationalize we would at least know, that having validated cognitive function, that the existence of cognitive function is real despite Plantinga's theory that it would be nearly non-existent.
So we must test it. Here is my proposal.
Here are five simple problems to solve for both test groups. Remember, group A gets to use their "thinking caps" while group B must solve the problems with a coin toss.
1. Before eating your breakfast cereal, should you a) poor milk onto it, or b) poor gasoline onto it?
2. Is the following sentence grammatically correct? "Colorless green ideas sleep furiously."
3. John is twenty years younger than Amy, and in five years' time he will be half her age. What is John's age now?
4. Solve for J:
- J = A − 20
- J + 5 = (A + 5)/2
5. Do problems #3 and #4 represent the same question, yes or no?
Now, just as an aside, I do not expect anyone to actually eat the cereal with the gasoline on it, as it would likely prove lethal, or at the very least, make them horribly ill.
My point here was to show that our cognitive capacity to rationalize should always met out the correct answer, unless of course, the person is brain damaged or mentally ill and cannot differentiate between something toxic like gasoline and something like milk. But such a case would be so rare that it probably needs no further consideration.
The test reveals the cognitive capacity to rationalize and think through the problems outweighs the random coin tosses when giving us the correct answer, allowing us to definitively say that human cognitive function exists while evolution and naturalism both are true--and this would just make Plantinga's argument a non-sequitur, because it hinges on the notion that cognitive function would either be an illusion, in which case his argument is mute, or extremely low--which it does not appear to be. It's a 100% verifiable.
Proof of cognitive function, then, renders the claim that naturalism and evolution cannot both be true erroneous. By initiating the test which is designed to prove and confirm that cognitive processes are not an illusion, because they are shown work when aiding us in problem solving whereas random coin tosses do not work, allows us to dismiss Plantinga's theory as incorrect and Plantinga's premise is falsified.
A simpler, more basic, test which does likewise is is to take a picture of red colored square, with the following question written in black letters underneath, "What color is the (above) triangle, yellow or blue?" and show it to someone. Have them read the card, and then watch their reaction to the cognitive dissonance it generates.
A thinking mind could and should be able to detect the dilemma that causes cognitive dissonance. There is no triangle, it's a square. It's not yellow nor blue, but it is red.
Of course, anyone can do this because we all recognized there are such things as different colors, or at least we believe there are, and the ability to detect the difference shows we hold a basic belief about the difference between colors. The same goes for detecting different shapes.
Moreover, our belief that the question is misleading, and wrong, and our cognitive capacity to make a correlation between the image and the incorrect information imbedded within the questioning cannot be, as Plantinga admits, an illusion. If it were, it would suggest that the belief that triangles and squares are geometrically dissimilar is false. It would suggest that, in actuality, they are the same.
Now stop to think about this for a moment... how can two entirely different geometric objects, each containing a different number of points and lines, be indistinguishable from one another? They can't. This falsifies Plantinga's theory--because we can rationalize that our belief in the difference of colors and shapes is not an illusion when it is a proberly basic belief, otherwise there is no such thing as properly basic beliefs.
[Note: The beliefs being properly basic, if cognition was an illusion, then cognitive dissonance couldn't arrise. An illusion cannot arise from the destruction of a prior illusion, unless of course, the beliefs weren't properly basic to begin with. Red is red, not yellow nor blue. If it were an illusion, then this admits that red could be classified as something other than red, but it appears to us redly so it must be a properly basic belief. Hence, it cannot appear to us wrongly, meaning if it is said to be a color other than it appears to be, then our cognitive reasoning kicks in and informs us that something is not right, i.e. it sparks cognitive dissonance, thereby demonstrating cognition is not inscrutable or illusionary, but is entirely real.]Whether or not evolution and naturalism negate each other, it seems that such an inference is refuted by the basic evidence we contain which shows evolution to be a natural process. Maybe there is something more philosophically complex that I am missing, but not being a professional philosopher, perhaps I am not qualified to say, but Stephen Law refutes Plantinga's theory here, showing evolution and naturalism to be fully compatible.
Personally, knowing that our cognitive function isn't impaired in the slightest, and knowing the abundance of natural evidence which suggests evolution is true, I would surmise that Plantinga has probably misunderstood something about the nature of evolution or has not fully thought out naturalism. I would hate to have to say this about such an esteemed philosopher, but one has to wonder, why such an esteemed philosopher never thought about how his theory might be falsified and discredited. I mean, it doesn't take a genius to give you the correct rational response to, "Should you poor milk on your breakfast cereal or gasoline?" You can ask any child and they'll give you the correct answer.
Such a simple test should have been considered by Plantinga before he posited his theory--but having failed to do so makes him seem like either a bad philosopher, dead wrong, or biased to the point where he can't seem to admit that his theory is a non-sequitur from the start; which means Plantinga doesn't expect his theory to be falsified--he expects you to agree with him that naturalism and evolution are incompatible (or inscrutable). Which they are not, due to the amazing gift we have which is cognition and the ability to think rationally, as proved by my five question quiz and simple cognitive function test with the red square.
Therefore, I have offered a scientific proof, a test anyone can run (and see for themselves), which proves cognition and completely falsifies Plantinga's theory that N&E are incompatible. The only recourse Plantinga has now is to point out that N&E together only make our cognitive facilities a low probability--not entirely impossible--just improbable. But if that is the recourse, then why offer the theory in the first place? As you can clearly see, the theory is a non-sequitur no any which way you look at it. It beats me why philosophers continue to keep resurrecting it. It didn't work for C.S. Lewis back when he offered it in his book Miracles, and it certainly doesn't work for Plantinga now.
Although it is not directly related to the above essay, I felt I needed to share the observation I made while thinking about how to falsify Plantinga's theory. It seems to me, the above refutation highlights an issue philosophers like Plantinga, and those who follow in his footsteps, need to start to seriously address. Science can discredit poor philosophy, but philosophy will never be able to discredit science.
[ If you're not familiar with Alvin Plantinga, or his work, I have provided a link which Plantinga explains properly basic beliefs. I'll let you decide the merit of his arguments for yourself.]