What makes people irrational thinkers?

[Angrboda]

I want to point out one other thing Hart says close to the beginning of his diatribe (page 17-18):

"If, moreover, naturalism is correct (how-
ever implausible that is), and if consciousness is then an essentially
material phenomenon, then there is no reason to believe that our
minds, having evolved purely through natural selection, could pos-
sibly be capable of knowing what is or is not true about reality as
a whole. Our brains may necessarily have equipped us to recog-
nize certain sorts of physical objects around us and enabled us to
react to them; but, beyond that, we can assume only that nature
will have selected just those behaviors in us most conducive to
our survival, along with whatever structures of thought and belief
might be essentially or accidentally associated with them, and there
is no reason to suppose that such structures—even those that pro-
vide us with our notions of what constitutes a sound rational ar-
gument—have access to any abstract “truth” about the totality of
things. This yields the delightful paradox that, if naturalism is true
as a picture of reality, it is necessarily false as a philosophical pre-
cept; for no one’s belief in the truth of naturalism could corre-
spond to reality except through a shocking coincidence (or, better,
a miracle)."

If I recall correctly it was C.S. Lewis who popularized this argument, and other theists have jumped on the bandwagon. The big problem is that it's nothing more than a fallacious appeal to consequences. Yes, it would seem bad if all our reasoning were futile and we were just fooling ourselves. Yes, our arguments for naturalism could well be flawed and unreliable if this were true. But that doesn't mean they would be wrong. That's an example of the fallacy fallacy at a different level. The fact that an argument is flawed doesn't mean that the conclusion is false. That's a fallacious conclusion. So what would be the final tally? Yeah, our philosophical arguments would have a fatal flaw in that one necessary premise, that our reasoning is a reliable guide to truth, would be false, and therefore the entire argument invalid. That wouldn't mean the conclusion is untrue. Yes, it would suck if our reasoning were unreliable, but so what? If it's unreliable it's unreliable; that being a bad thing doesn't make it untrue.

Moreover, I think that anyone who seriously thinks that the utility of our thinking has no relation to its truth is willfully ignoring evidence to the contrary.