|I ate this fig and portabella mushroom pizza in Boston.|
Naturalists are, for the most part, materialists about human persons: "a human person is a material object through and through, with no immaterial self or soul or subject." (17)
Let N mean naturalism, let E mean current evoutionary theory, and let R mean the proposition that our cognitive faculties are reliable.
Plantinga then reasons:
1. P (R/N&E) is low. (Read this as: "The probability of R, given N & E.")
2. One who accepts N&E and also sees that 1 is true has a defeater for R.
3. This defeater can't be defeated.
4. One who has a defeater for R has a defeater for any belief she takes to be produced by her cogbitive faculties, to include N&E.
5. Therefore N&E is self-defeating and can't be rationally accepted. (I.e., naturalism is incompatible with evolutionary theory.)
See pp. 17-21 for Plantinga's defense of these premises. At the heart of this is the idea that "natural selection doesn't give a fig for true belief just as such. It rewards adaptive behavior and punishes maladaptive behavior, but it doesn't cafre aboutr truth of belief; as Patricia Churchland says, "Truth, whatever that is, definitely takes the hindmost." (19)
Dennett responds to this, Plantinga responds back, the Dennett again, then Plantinga one more time.