Wednesday, May 20, 2009

Alvin Plantinga on the Evolutionary Argument Against Naturalism

The philosopher wrote an article for the layman on his "Evolutionary Argument Against Naturalism". It may be read here.

3 comments:

atimetorend said...

Thanks for posting, I liked the "for the layman" part, wouldn't have clicked through otherwise. I am not educated in philosophy and am looking forward to some comments here.

Couple of questions:
- When Plantinga discuss the 50% odds of a given belief being true, it seems to me that is only correct if you are operating in a vacuum of information. Don't the beliefs get tested to see if they are true? The frog would eventually deduce the probability that flies are only food to be much higher than the chance they will turn him into a prince. It seems this point only shows belief in God could be a logical outcome of a naturalistic human in a naturalistic environment.

- Even if you demonstrate strong belief in naturalism to be unwarranted because we cannot trust the accuracy of our beliefs, practically we still have beliefs, so how does that make it incompatible with belief in evolution? It seems to me the author is arguing against confidence in beliefs, not against compatibility of belief in naturalism and evolution

AIGBusted said...

"- When Plantinga discuss the 50% odds of a given belief being true, it seems to me that is only correct if you are operating in a vacuum of information. Don't the beliefs get tested to see if they are true? The frog would eventually deduce the probability that flies are only food to be much higher than the chance they will turn him into a prince. It seems this point only shows belief in God could be a logical outcome of a naturalistic human in a naturalistic environment."

That's a good point, and one I bring up in my book "Atheism and Naturalism". However, I think the strongest point against Plantinga's argument is the following (from my book):

"The real nail in the coffin for Plantinga’s argument is that specific and situational beliefs (and desires) are not things which evolve. There are no genes for a belief that John F. Kennedy was assassinated by the government or that Mars is home to lots of little green men.


"Our specific, situational beliefs are not products of evolution, but our more general beliefs, which hold true under all circumstances, may be. Abstract reasoning, the use of deductive logic, and mathematical reasoning may very well be things which our brains were hard-wired to use by natural selection. And these general principles are much less likely to be false in light of the fact that they should not be adaptive if they were false. How could a false method of reasoning be as adaptive as a true system of reasoning? Under what circumstances could creatures evolve to think that two plus two is thirteen or that contradictions can exist? Unless and until Plantinga can come up with a plausible scenario which would make such an evolutionary step possible, his argument will prove unpersuasive."



"- Even if you demonstrate strong belief in naturalism to be unwarranted because we cannot trust the accuracy of our beliefs, practically we still have beliefs, so how does that make it incompatible with belief in evolution? It seems to me the author is arguing against confidence in beliefs, not against compatibility of belief in naturalism and evolution"

His point is that a belief in both naturalism and evolution would be self contradictory, since if you cannot trust your cognitive faculties are reliable you cannot trust that you've made the right decision in acception Evolution and/or Naturalism.

Anonymous said...

You state: >>>Abstract reasoning, the use of deductive logic, and mathematical reasoning may very well be things which our brains were hard-wired to use by natural selection. And these general principles are much less likely to be false in light of the fact that they should not be adaptive if they were false. How could a false method of reasoning be as adaptive as a true system of reasoning?<<<

Belief in some form of the supernatural (God, ESP, etc.) is prevalent, most studies have it as high as 90%. This does not mean it is correct, of course, but it shows how our brains may be hardwired for incorrect beliefs (incorrect only if you do not believe in any form of the supernatural) and still succeed through evolution. This is the plausible scenario you are looking for.