The 'argument from reason' has cropped up a few times on the Unbelievable show, and reared its head on last week's show again. The argument is basically this: Reason cannot emerge from non-reason. In a naturalistic worldview, reason (i.e. our cognitive ability to reason) is the end result of a non-rational process (i.e. evolution by natural selection). We know we are reasonable. Therefore, the naturalistic worldview is false. Of course, there's more nuance to it than that, but that's the gist.
There are two thoughts I have on this.
The first is to question the first premise of the argument. Why can't reason emerge from non-reason? Evolution theory has shown, quite convincingly, that complexity can arise from simple systems. The ability to infer from evidence gives us a huge evolutionary advantage over instinct-driven creatures. Why shouldn't this ability have evolved?
The other is to point out that, whichever side you take in the belief/non-belief debate, there would seem to be a vast number of people in the world who do not exhibit total rationality. If there is a God, and there is evidence of his existence, then all non-believers are non-rational. If there is no God, and the evidence is nothing of the sort, then all believers are non-rational. Either way, non-rationality is rampant in the world. The apparent existence of rationality in the small subset of people who happen to infer the same things about reality as me should not be taken to imply that people are generally rational. Quite the opposite. People are generally irrational. Is this design or is this the end result of an evolutionary process?
Inferring the existence of God on the basis of a characteristic which might be found in a small subset of people (and might be found in nobody; I can't prove that anyone is rational) is a very shaky argument. Maybe we're all non-rational?