Friday, August 13, 2010

Plantinga on evolution and naturalism

I just came across pharyngula's criticism of Plantinga's short, sweet version of his argument against naturalism. It is here if you are interested.

Plantinga still runs the following type of argument that false beliefs are just as adapative as true beliefs, and so evolution won't particularly favour true-belief-producing mechanisms:

Consider a frog sitting on a lily pad. A fly passes by; the frog flicks out its tongue to capture it. Perhaps the neurophysiology that causes it to do so, also causes beliefs. As far as survival and reproduction is concerned, it won't matter at all what these beliefs are: if that adaptive neurophysiology causes true belief (e.g., those little black things are good to eat), fine. But if it causes false belief (e.g., if I catch the right one, I'll turn into a prince), that's fine too.

6 comments:

Steven Carr said...

I've never understood Plantinga's arguments.

How did evolution produce the true belief that Chelsea won the Premier League last season?

It didn't.

Therefore, there is a God.

Can somebody point out the flaw in this argument?

David B. Ellis said...

Plantinga's argument, in every version of it I've read, never gets off the ground in the first place. He points out the bare logical possibility that false beliefs can be survival-promoting (as in his absurd tiger story) and blithely skips the rather important step of giving us good reason for concluding that globally unreliable cognitive faculties are not merely logically possible but even remotely plausible.

He doesn't do this and it MUST be done for naturalism to have a problem. PZ Meyers is right. Plantinga is a joke....and he's widely regarded by Christians as being one of the best living Christian philosophers.

The pathetic thing is that they're probably right.

NAL said...

If we possess unreliable cognitive mechanisms, then Plantinga's argument is unreliable and we should not accept it.

If we possess reliable cognitive mechanisms, then those who argue for naturalism are reliable and we should accept their argument.

If our cognitive mechanisms are sometimes reliable and sometimes unreliable, then what does that say about God?

David B. Ellis said...


If we possess unreliable cognitive mechanisms, then Plantinga's argument is unreliable and we should not accept it.

If we possess reliable cognitive mechanisms, then those who argue for naturalism are reliable and we should accept their argument.



There are plenty of good reasons to think Plantinga's argument terribly bad but what you describe is not one of them. Regarding the second half of your quoted statements, having reliable cognitive faculties (RCF, for short, should this conversation continue) does not mean one is not capable of error.

Also, Plantinga thinks, in fact, that we DO have reliable cognitive faculties (since, he think, there is a God who wanted us to have them). So the first half of your comment is not applicable to the argument either.

Patrick said...

David Ellis- I understand what you're saying, but I'm pretty sure Plantinga's argument is so dumb that NAL's criticism really works. Plantinga treats "reliable cognitive faculties" as a sort of magical belief generating apparatus that kicks out beliefs as wholly formed units of data with no precursors in observation or experience, which are then acted upon by evolution as unitary concepts to be selected for or against.

If we possess reliable cognitive faculties as Plantinga describes it, it really is adequate to state that my reliable cognitive faculties have generated naturalism, ergo naturalism. That's exactly how beliefs work in this argument. Reliable cognitive faculties make stuff up out of whole cloth, and then maybe you get eaten by a tiger.

I mean, that's stupid and generates a contradiction given that Plantinga's reliable cognitive faculties have generated a belief that contradicts mine, but I'm pretty sure the contradiction is his fault.

Matt said...

"Plantinga's argument, in every version of it I've read, never gets off the ground in the first place. He points out the bare logical possibility that false beliefs can be survival-promoting (as in his absurd tiger story) and blithely skips the rather important step of giving us good reason for concluding that globally unreliable cognitive faculties are not merely logically possible but even remotely plausible."

Then you have not read many versions of Plantinga's argument. Because he gives quite a detailed argument as to why he thinks this is probable on naturalism.