2009-03-08
Epistemology Without Foundations
I do now know how much serious discussion among professional philosophers has been devoted Plantinga's argument that evolutionary theory provides an argument against naturalism, though I know it is widely heralded by many non-professionals who do not like evolutionary theory.

Plantinga's error is two-fold.  First, he fails to state his general epistemological position, and so leaves us wondering what he means by "truth."  Second, and more detrimental to his argument, he fails to consider the possibility of epistemological behaviorism.

Consider any of Plantinga's examples of how evolution might have one survive perfectly well with a set of mostly false beliefs.  One might, for example, run up a tree when confronted with a tiger, because one believed that this was the best way to pet the cute, furry animal.  Thus, one's actions would lead to survivale, but one would be acting on a false belief.

Under what conditions could we establish that this man believed one thing, and not another?  What does it mean to say that he believes the best way to put a tiger is to run away from it?  That is, in what conditions could we observe him and say, ah, yes, he believes that is how he should go about petting the tiger?

For Plantinga's argument to work, there cannot be any such conditions.

One might here wish to defend Plantinga's argument by imagining a conversation with this hypothetical man.  We might ask him, "What are you running away from these tigers?"  But how could we understand his response?  He might say, "Because I want to pet them!"  We would think he was either mad, joking, or speaking a different language.  How could we communicate with such a person at all, if all of his words contradicted our understanding of his behavior?

There are no conditions for which we could understand such a person's beliefs, and so Plantinga has no grounds for claiming that such a person could behave in this way and have the beliefs he says they do.

This is a fatal flaw in Plantinga's argument, but it does not fully counter the intuition which Plantinga and his supporters maintain:  namely, that evolutionary theory cannot account for truth.  To uncover the full depth of Plantinga's error, we have to look at just how evolution could have selected for truth.  That is, we must come to a more feasible notion of true belief. 

And here it is quite simple:  for we have no trouble understanding how evolution could select for the ability to develop and utilize various tools, and why not think that language is such a tool?  If we think of language as a tool for furthering our successful reproduction, we can regard the category of "truth" as one aspect of that tool.  Specifically, it is that aspect of the tool which turns language upon itself in a process of evaluation.  "Truth" is what we call language when it works for our ends.  Evolutionary theory does not say that our only end is reproduction; rather, it says that our ability to reproduce explains why we are the way we are.  Our ends can thus be explained in terms of reproduction without being reduced to them.  And so we can talk about truth without talking specifically about what will or won't lead to reproduction. 

The main point here is that truth is a matter of what works, and that is all a matter of behavior.  This is precisely why we could not possibly understand the beliefs of somebody such as Plantinga describes, and why we should have no problem acknowledging our evolutionary origins whilst rejecting supernaturalism.