Here’s how Alvin Plantinga summarises the evolutionary argument against naturalism (EAAN) in his book Where the Conflict Really Lies (p. 314):1
The basic idea of my argument could be put (a bit crudely) as follows. First, the probability of our cognitive faculties being reliable, given naturalism and evolution, is low. (To put it a bit inaccurately but suggestively, if naturalism and evolution were both true, our cognitive faculties would very likely not be reliable.) But then according to the second premise of my argument, if I believe both naturalism and evolution, I have a defeater for my intuitive assumption that my cognitive faculties are reliable. If I have a defeater for that belief, however, then I have a defeater for any belief I take to be produced by my cognitive faculties. That means that I have a defeater for my belief that naturalism and evolution are true. So my belief that naturalism and evolution are true gives me a defeater for that very belief; that belief shoots itself in the foot and is self-referentially incoherent; therefore I cannot rationally accept it. And if one can’t accept both naturalism and evolution, that pillar of current science, then there is serious conflict between naturalism and science.
Probably the most common objection to the EAAN is that biological organisms with generally reliable cognitive faculties—that tend to produce beliefs with true content—will survive better than biological organisms with generally unreliable cognitive faculties, and so the evolutionary process will select for the former over the latter.
But this objection misses the point. On naturalism, the evolutionary process does not care whether or not adaptive neurophysiological properties generally correspond to beliefs with true content; it will select for adaptive neurophysiological properties, not for neurophysiological properties that correspond to beliefs with true content. And, on naturalism, there’s no reason to think that adaptive neurophysiological properties do in fact generally correspond to beliefs with true content.
This appears to put the naturalist in a slightly sticky situation, to say the least. And things do look somewhat better for the Christian theist who believes, perhaps in a properly basic way, that God exists and has (in one way or another) created human beings and the physical world in such a way that human beings can have non-trivial knowledge about reality.
1 Plantinga, Alvin (2012). Where the Conflict Really Lies: Science, Religion, and Naturalism. Oxford University Press.
Image from Wikimedia Commons.
Originally posted at TomLarsen.org.