Monday 20 August 2007

Naturalising Epistemology: Quine vs. Crumley (Part 2)

In my previous post I outlined two objections presented by Jack Crumley to Quinean naturalised epistemology. While I’m not altogether unsympathetic to Crumley’s process, I believe that as they stand, Crumley’s objections require further defence.

Crumley claims that nature may favour belief-forming mechanism that form false beliefs. However, Crumley seems to be overstating the case. (Here, Quine’s frequent admonition seems quite apt: let's not overreact.) The survival value of being overly cautious is limited to certain special situations and circumstances. However, a general paranoia is as equally destructive as the alternative. For example, the individual that runs every time the bush rustles because she assumes it is a lion will prove less adaptively fit than the one who learns to tell the difference between the bush rustle caused by a lion (potential predator) and a rabbit (potential prey). While being overly cautious may prove evolutionary valuable in specific circumstances, it is detrimental if had as a general practice.

Additionally, Pascal Boyer (2001) notes that our tendency to err on side of caution (what he refers to as our over-active agency detection system) is balanced by our ability to quickly revise our beliefs in the face of contrary evidence. That is, evolution has endowed us with various mechanisms of self-correction that pre-empts our occasional over cautiousness developing into a detrimental general paranoia.

Moreover, one of the reasons for engaging in the study of evolutionary epistemology is to uncover what natural biases nature has built into our belief forming mechanisms so that we may better take these biases into account. In this regard, the practice of evolutionary epistemology is itself simply an expression of one of the many truth-conducive mechanisms nature has given us.

Crumley's second objection is that many of our scientific beliefs seem to lack survival value. However, what the evolutionary epistemologist claims is not that our beliefs, but rather that our belief forming mechanisms have been selected by evolution because of their survival value. This posit does not imply that all of the applications of our belief forming mechanism must in some way impact on survival. Rather, it simply means that the story behind why a certain cognitive mechanism first came to be generally employed is because of its survival value.

For example, no one would doubt that from an evolutionary standpoint the primary purpose of sex is reproduction. However, the evolutionary account of the origins of sexual behaviour has not prevented it from extending to a much broader array of contexts. In fact, as many college students can testify, reproduction is often the least desirable outcome as far as our sexual practices are concerned.

Likewise, the original contexts and reasons why our epistemic practices emerged place no set limits on their expression or application. To put the matter somewhat poetically, the very cognitive mechanisms that once enabled us to tell the difference between a lion or rabbit in the bushes may also enable us to decipher the chemical makeup of a distant star.

References:
Boyer, Pascal, Religion Explained: The Evolutionary Origins of Religious Thought. New York: Basic Books, 2001.

Crumley, Jack, An Introduction to Epistemology. California: Mayfield Publishing Co., 1999.

Quine, W.V.O., "Epistemology Naturalized." Naturalizing Epistemology. Edited by Hilary Kornblith. Cambridge, MA.: The MIT Press, 1994.

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