This is a post in response to an atheist claim for rationality as against the supposed Christian irrationality.
On the issue of cognitive dissonance, it would seem clear that materialism relies on a foundation that supports nothing else, since it cannot justify reason itself. A materialist, by virtue of his own creed, “believe[s] something [i.e., reason] for which the evidence wasn’t present”. As Darwin himself stated:
With me the horrid doubt always arises whether the convictions of man’s mind, which has been developed from the mind of the lower animals, are of any value or at all trustworthy. Would any one trust in the convictions of a monkey’s mind…?
As well, materialism is monistic – for a materialist, there is only ever one thing: matter. If rationality and knowledge of truth involves making distinctions, it’s doomed in such a task right from the outset.
‘Rationality’ so-called in materialism, then, involves cognitive dissonance at two most defining points – in its foundation, and in its end (knowledge of things).