Tuesday, October 08, 2013

the accuracy of an evolved brain

I've encountered more than a few philosophical arguments for faith beliefs. Clearly, I'm no longer convinced by any of these. In fact, I've since realized that the field of apologetics isn't as deeply appreciated by unbelievers as it is by doubting believers, who are quicker to welcome its thin justifications. Nevertheless, like other impractical philosophical topics, these are adequate points for the purpose of frivolous discussion. And a blog is an adequate medium for the purpose of frivolous discussion...

Today's example: "Unlike materialistic naturalism, my religious beliefs assume that the right set of human ideas is utterly accurate. Utter accuracy is possible because human souls aren't vulnerable to the normal imperfections and limitations of physical matter. Also, reality is comprehensible to humanity because both originated from the same source: one or more unearthly souls that value accuracy and think like a human's soul. My explicit basis for accuracy is tidy and comforting and trustworthy. It's a better fit for my preferences than the alternative notion of human ideas existing as mere physical events in a brain. A brain is just a smallish body organ originating from evolution, and evolution obviously isn't a soul which painstakingly engineers accurate thinkers. It's the impersonal tendency to maximize rates of survival and reproduction. So how can anyone be as satisfied with the accuracy of an evolved brain?"

What makes this argument so fascinating to me is that, well, I sorta continue to agree with part of it. I readily concede that evolution hasn't resulted in a brain that always extracts accurate information and then arrives at appropriate inferences. Instead, one common thread in the systematic study of human perception/memory is that humans don't leave information as-is. Nor do they typically analyze information with unassuming mathematical logic. Humans ignore and embellish and filter and overgeneralize. They apply patterns so hastily that they routinely perceive/remember whatever they expect. The importance of context shouldn't be underestimated.

This finding is consistent with a survival "goal" of rapid efficient tactical responses. These only require vague short-cut answers which are reached through scarce energy-consuming bodily resources. Without cultural training, an evolved brain isn't an unbiased and dispassionate investigator. Its first question is, "How will the new information affect me here and now?" Humans may proceed to laboriously sift information at advanced levels of reason, but those levels don't replace the primitive level. Hence the religious argument isn't too far off the mark when it expresses anxiety about the basic fallibility of an evolved brain; to the contrary, its mistake is its failure to also acknowledge that its anxiety has been confirmed countless times by real behavior. And those confirmations support evolved brains over aloof souls.

More amusing still, the argument itself amounts to a complaint about the emotionally unsatisfying implications of the opposing conclusion. "I don't like a challenging conclusion very much, so I refuse to think it's accurate." It's undisguised motivated reasoning. But the existence of motivated reasoning is a decisive clue in favor of evolved brains as opposed to aloof souls. As mentioned earlier, it's consistent for an evolved brain to attempt to obtain answers by measuring with an egocentric standard such as "How does this conclusion affect my feelings?" It's not consistent for the same egocentric standard to be measured by an alleged aloof, impartial, abstract, deep, spiritual soul. Generally, according to one of its definitions, faith is a specimen of motivated reasoning: accepting an idea to serve some purpose, regardless of factual proof. Why would humans crave religion's psychological payoffs, such as promises of utterly accurate information, if not due to impulses shaped by evolution? It's subtly self-contradictory when the argument entices the hearer's belief with a relative emotional reward...given that reward-seeking evolved brains are likelier to be, uh, persuaded by such relative emotional rewards.

On the other hand, I might not be expressing the argument most effectively. Perhaps it's intended to present a straightforward logical contradiction: "Unlike my religious beliefs, materialistic naturalism isn't as dependent on the notion of utter accuracy. Therefore it cannot be true because it implies that all statements are false." To which I reply: er...no. Non sequitur. I'll repeat my usual refrain. Real accuracy is a measurement resulting from many various mental and/or physical actions—perhaps more than one, to alleviate the effect of each action's possible defects. Some accuracy is already as "utter" as anyone could ask; despite my lack of an aloof soul I can determine with utter accuracy the quantity of future days in the present month. Meanwhile some accuracy isn't utter but everyone copes; I don't know every last digit of today's balance in all my interest-accruing bank accounts, but I'm sure the amount is greater than ________.

Similarly, the accuracy of the proposition "Human thought is a product of an evolved brain" is measured by actions. When someone observes X, do they observe Y too? Utter accuracy is certainly a pleasant goal, but its frequent absence doesn't eliminate the achievement of lesser accuracy. In practice we don't foolishly presume that any human constructs and emits perfect representations of reality. That's why we take measurements known as "expertise", and why we demand to know what someone means when they speak. It's awfully suspicious whenever someone tries to circumvent their evaluation by saying, "Accept my utterly accurate information because it somehow arose without the action of evolved human brains, unlike every other less grandiose item of information."