Omar Mirza has a forthcoming paper in Phil. Studies (available in SpringLink in the ‘OnlineFirst’ section) where he (among other things) examines three standard objections to EAAN, shows that Plantinga’s responses are faulty, and then provides his own responses. (For other Prosblogion discussion of EAAN, see here, here, and here. For Plantinga’s most important paper on it, see here.)
I want to examine his response to the tu quo que objection. Now it’s dangerous to reach into the middle of a complicated dialectic and pull out relevant little bits for discussion, but that’s what I’ll try to do! (There is a possibility that I will make hermeneutical errors; I take full responsibility and am open to correction!)
EAAN is as follows:
Probability thesis: P(R/N&E) is low or inscrutable
Defeater thesis: The naturalist who accepts N, E, and the probability thesis has a defeater for R.
It then follows that the naturalist has a defeater for all his beliefs, including his belief in naturalism. So naturalism is self-defeating.
The tu quo que objector attacks the defeater thesis. Where austere theism is the view that God exists (but does not include any content about God creating us as reliable knowers or in his image or whatever), he points out the following:
Probability thesis*: P(R/A) is low or inscrutable
Defeater thesis*: The theist who accepts A and probability thesis* has a defeater for R.
So the theist has a defeater for all his beliefs, including his belief in theism. So theism is self-defeating.
The naturalist can therefore push that he has as much reason to accept the defeater thesis as the theist has to accept the defeater thesis*. The arguments fall or stand together.
The defender of EAAN must give a good reason why the naturalist should accept the defeater thesis that is not a good reason for the theist to accept probability thesis* [TYPO, I SHOULD HAVE SAID ‘defeater thesis*’ HERE. THIS EDIT WAS MADE ON 10:36pm, 6/15/08]. Plantinga has his own strategy for doing this, but I’m interested in Mirza’s right now. The sort of defeater that Mirza thinks is relevant for EAAN is an undercutting defeater, which he defines as a defeater that “undermines the trustworthiness of [a] belief’s source”. How does naturalism do this? Given that Plantinga’s reasons for accepting the probability thesis are good (that’s a whole other discussion), it is the case that if naturalism is true, then “during the operation of the process that resulted in the creation of human cognitive faculties, there were no conditions that could serve to filter out unreliable cognitive faculties. Or, as we might put it, the process did not involve any filter of unreliable cognitive faculties” (section 2 of his paper).
Now what’s the difference between the theist and the naturalist? He writes, “the theist has not been given any grounds for doubting that the process she believes created her cognitive faculties involved a filter of unreliable cognitive faculties…” (section 4.2.5). So while the naturalist, via the probability thesis (and the reasoning for the probability thesis) has been given positive grounds for doubting that the process which created her faculties involved a filter of unreliable cognitive faculties, the theist does not have these positive grounds.
This response seems to me promising. Any thoughts?