“If a belief is as likely to be false as to be true, we’d have to say the probability that any particular belief is true is about 50 percent. Now suppose we had a total of 100 independent beliefs (of course, we have many more). Remember that the probability that all of a group of beliefs are true is the multiplication of all their individual probabilities. Even if we set a fairly low bar for reliability — say, that at least two-thirds (67 percent) of our beliefs are true — our overall reliability, given materialism and evolution, is exceedingly low: something like .0004. So if you accept both materialism and evolution, you have good reason to believe that your belief-producing faculties are not reliable.”
On the (New York Times) philosophy blog The Stone, I spotted this entry and first wondered if I had misread the title, as atheism sounds (to me) as a most rational position. I then read the piece and found it mostly missing, even though a few points rang true(r). First, theism is never properly defined. (Even though the author Alvin Plantinga seems to stick to monotheist religions.) This is a not-so-subtle trick as it makes atheism appear as the extreme position, since it is rejecting any form of theism! Then, the interviewee is mostly using a sequence of sophisms as arguments that atheists are irrational, see e.g. the even-star-ism and a-moonism and a-teapotism entries. Further, some of his entries very strongly resemble intelligent design arguments, e.g. the “fine-tuning” line that the universe is too perfectly suited to human life to be due to randomness. Even though Plantinga also resorts to evolution when needed, as in the above quote. (The interviewer is not doing a great job either, by referring to evil, or the need (or lack thereof) of God versus science to explain the world. Rather than resorting to rational arguments. And without mentioning the fundamental point in favour of atheism that the existence of a sentient being driving the whole universe while remaining hidden to us humans requires an infinitely stronger step than arguing this is impossibly incompatible with the laws of Physics and the accumulated corpus of experience since the dawn of humanity.) The whole strategy of Plantinga is actually to turn atheism into another kind of belief “that materialism and evolution are true” and then to rank it equal with the theisms. A very poor philosophical performance. As also (and better) pointed out in this other post. (And as my daughter remarked, fresh from writing a philosophy essay, Plantinga is missing the best argument of all, namely Pascal’s wager, an early instance of decision theory applied to religion.)