Evolutionary Argument Against Naturalism

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Summary in 400 words or less:

The Evolutionary Argument Against Naturalism (EAAN) is an argument developed by Christian Philosopher, Alvin Plantinga.

Naturalism (or materialism) means that the substance of reality is only physical. One may hold on to Atheism but not necessarily be a naturalist. Evolution refers to human beings coming to be by the blind process of natural selection (random genetic mutation). Plantinga’s argument is that one cannot accept both rationally.

He argues that if naturalism and evolution (N&E) is true, one’s neurology is adapted to promote survival and reproduction. If the behavior is adapted,the truth of one’s belief doesn’t matter. Natural selection favors advantageous behaviors, not directly the ability to form true beliefs. Hence the probability of the reliability of our cognitive faculties (R) is low or inscrutable given the truth of N&E. In other words, the P(R/N&E) is low. If so, then there is a defeater for R. If so, then this becomes a defeater for all our beliefs, including N&E. Hence holding N&E is self-defeating or self-referentially incoherent.

Now Plantinga takes it that the main issue is the P(R/N&E). To determine this then, he goes through 4 possibilities between behavior and belief.

1. Epiphenomenalism Simpliciter

Here behavior is not caused by belief (or any mental phenomenon like emotions).

2. Semantic Epiphenomenalism

Here beliefs do indeed have causal efficacy with respect to behavior but not by virtue of their content (by virtue of syntax, not by virtue of semantics). Belief is a long-term pattern of neural activity or a long-term neuronal event which has two different properties: (1) Syntactical properties which are electrochemical/neurophysiological properties (eg. number of neurons, their connections, rate and strength at which they fire, the way they change over time to other neural activity) and (2) Semantical properties (eg. propositions, being true or false).

3. Beliefs are both semantically and syntactically causally efficacious on behavior but maladaptive (the behaviors are not adaptive). In the first place, this is very unlikely given evolution.
4. Beliefs are both semantically and syntactically causally efficacious on behavior and adaptive. If behavior is caused by belief, it is also caused by desire (and other factors such as suspicion, doubt, approval, fear). For any given adaptive action, there will be many belief-desire combinations that could produce that action; and many of those belief-desire combinations will involve false belief. For example, to run and survive from a Tiger, Paul thinks he is about to take part in a 1600 meter race, wants to win, and believes the appearance of the tiger is the starting signal. The probability of this possibility being true in the first place given naturalism is however very low, where the semantic content of a belief is involved in a causal chain leading to behavior.

In the first three options, R has very low probabilities while Plantinga says the fourth option couldn’t be more than 1/2. Given N&E, the probabilities of the first two possibilities being actual would be very high (as it is supported by biological science and philosophy of mind respectively), the third virtually not considered and the fourth low. Hence the total probability would either be low or inscrutable.

This is a powerful argument because it can only be defeated by something that involves some other belief. But any such belief will be subject to the very same defeater as R is. Any attempt to argue against this using intuitions or reasoning would be presupposing the reliability of one’s cognitive faculties being reliable. So there cannot be a defeater for this defeater. In light of having an undefeated defeater for R, then any belief that my unreliable cognitive faculties produce cannot be reliable either, which includes one’s belief in N&E.

Scripture for YouVersion: Romans 1:18-22

Short audio/video:

https://www.youtube.com/watch?v=vpQ1-AGPysM

https://www.youtube.com/watch?v=SJ5RPn6nlwo

https://www.youtube.com/watch?v=PwE_D9GUC0s (Long Lecture)

Three questions (one fill-in-the-blank, one multiple choice, one discussion question):

1. Naturalistic Evolution acts as a _________ for the reliability of our cognitive functions which in turns act as a _______ for Naturalistic Evolution.
2. Which has the least probability to being actually true?

(1) Beliefs are both semantically and syntactically causally efficacious on behavior but maladaptive

(2) Epiphenomenalism Simpliciter

(3) Beliefs are both semantically and syntactically causally efficacious on behavior and adaptive

(4) Semantic Epiphenomenalism

3. Why do you think that biological scientists hold to Epiphenomenalism Simpliciter while philosophers of mind hold to Semantic Epiphenomenalism?

References for further reading:

Plantinga, A. (1993). Warrant and proper function. New York: Oxford University Press.

http://www.calvin.edu/academic/philosophy/virtual_library/articles/plantinga_alvin/naturalism_defeated.pdf

Beilby, J. (2002). Naturalism defeated?: Essays on Plantinga’s evolutionary argument against naturalism. Ithaca: Cornell University Press.

Plantinga, A. (2011). Where the conflict really lies: Science, religion, and naturalism. New York: Oxford University Press.

Collaboration notes:

Collaborators: Frederick Choo
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