Plantinga's Evolutionary Argument Against Naturalism

[Tree of Life]

I've just finished Plantinga's book again - "Where the Conflict Really Lies". This is supposed to be his final form of the EAAN. As I've tried to synthesize it to be able to teach it, I continue to be persuaded that it's a strong argument.

The argument seeks to show that you cannot rationally accept both naturalism and evolution because this pair of beliefs is self-defeating. Here's the argument:

1. The probability (P) of our cognitive faculties being reliable (R) given naturalism and evolution (N&E) is low.
2. Anyone who believes N&E and sees that P(R/N&E) is low acquires a defeater for R.
3. Anyone who acquires a defeater for R acquires a defeater for all of her beliefs, including N&E.
4. If by believing N&E one acquires a defeater for N&E then N&E is self-defeating and cannot be rationally accepted.
5. Therefore N&E cannot be rationally accepted.

So there you have it. You cannot rationally be an atheist and also believe in evolution. How do you respond to this argument?

 

[zippy2006]

Great summation. I think all the weight of the argument falls to premise (1), which requires justification.

 

[Tree of Life]

Great summation. I think all the weight of the argument falls to premise (1), which requires justification.

It certainly does all rise and fall on premise 1. He spends a lot of time in the book arguing for premise 1. I'll do that here if anyone bites.

 

[Gene2memE]

Couple of issues with the EAAN:

Whether cognitive faculties are reliable or not is not a defeater for naturalism and evolution.

We know our cognitive faculties aren't wholly reliable. They also don't need to be completely reliable, as under natural selection they only need to be reliable enough to ensure survival and reproduction. Plantinga fails to demonstrate though that this results in a low probability that the mind produces true beliefs.

He completely ignores that fact that humans are a social species who check each others work. So, for any one individual the EAAN works, but it completely fails to account for group behaviours and population dynamics.

Oh, and it totally fails to account for the fact that non-human species seem to have reasonably reliable faculties as well. Very anthropocentric.

I'd also re-use Stephen Law's objection, that Plantinga ignores the conceptual links between belief content and behaviour, and their resulting impact to produce true beliefs.

 

[public hermit]

I've just finished Plantinga's book again - "Where the Conflict Really Lies". This is supposed to be his final form of the EAAN. As I've tried to synthesize it to be able to teach it, I continue to be persuaded that it's a strong argument.

The argument seeks to show that you cannot rationally accept both naturalism and evolution because this pair of beliefs is self-defeating. Here's the argument:

1. The probability (P) of our cognitive faculties being reliable (R) given naturalism and evolution (N&E) is low.
2. Anyone who believes N&E and sees that P(R/N&E) is low acquires a defeater for R.
3. Anyone who acquires a defeater for R acquires a defeater for all of her beliefs, including N&E.
4. If by believing N&E one acquires a defeater for N&E then N&E is self-defeating and cannot be rationally accepted.
5. Therefore N&E cannot be rationally accepted.

So there you have it. You cannot rationally be an atheist and also believe in evolution. How do you respond to this argument?

Great book! I think it's a convincing argument. And as usual, Plantinga's argument in the book is thorough.

The one question I had reading the book was the adaptive ability of our cognitive faculties. Per premise one, the probability that our cognitive faculties being reliable is low if we assume naturalism and evolution. The reason being that given those two assumptions all of our faculties, including our cognitive faculties, are aimed primarily at survival, not necessarily truth. If they are not primarily aimed at truth, they cannot be considered reliable in terms of truth. Perhaps believing lies is to our evolutionary advantage?

My question is: Wouldn't our cognitive abilities "hooking on to reality" in the right way be essential to survival? Over time, wouldn't our cognitive abilities adapt to reality in such a way that our beliefs would track what is actually the case more and more. It seems the proponent of N/E could argue that even though the primary function of our cognitive faculties is survival, survival entails seeing things in a true way, so that over time our cognitive abilities began to track the truth for survival reasons?

Plantinga addresses this objection pg.335 "C. Objection" where he says, "Isn't it obvious that true beliefs will facilitate adaptive action?" That was basically my concern. His rebuttal seems to be that particular objection depends on a counterfactual and he sees no reason, given the way things stand, that counterfactual should receive all that much attention. Whatever the case, I would say, that is the primary objection to his argument that the proponent of N/E has. Somehow, the proponent of N/E has to find a defeater for premise 1. That seems to be the best possible route for success, I think.

 

[Tree of Life]

Great book! I think it's a convincing argument. And as usual, Plantinga's argument in the book is thorough.

The one question I had reading the book was the adaptive ability of our cognitive faculties. Per premise one, the probability that our cognitive faculties being reliable is low if we assume naturalism and evolution. The reason being that given those two assumptions all of our faculties, including our cognitive faculties, are aimed primarily at survival, not necessarily truth. If they are not primarily aimed at truth, they cannot be considered reliable in terms of truth. Perhaps believing lies is to our evolutionary advantage?

My question is: Wouldn't our cognitive abilities "hooking on to reality" in the right way be essential to survival? Over time, wouldn't our cognitive abilities adapt to reality in such a way that our beliefs would track what is actually the case more and more. It seems the proponent of N/E could argue that even though the primary function of our cognitive faculties is survival, survival entails seeing things in a true way, so that over time our cognitive abilities began to track the truth for survival reasons?

Plantinga addresses this objection pg.335 "C. Objection" where he says, "Isn't it obvious that true beliefs will facilitate adaptive action?" That was basically my concern. His rebuttal seems to be that particular objection depends on a counterfactual and he sees no reason, given the way things stand, that counterfactual should receive all that much attention. Whatever the case, I would say, that is the primary objection to his argument that the proponent of N/E has. Somehow, the proponent of N/E has to find a defeater for premise 1. That seems to be the best possible route for success, I think.

As I understand it, Plantinga argues that there is no necessary connection between true belief and right behavior. Our immune systems, for example, behave rightly and intelligently but they do so totally independently of our awareness and our belief.

 

[Gene2memE]

As I understand it, Plantinga argues that there is no necessary connection between true belief and right behavior. Our immune systems, for example, behave rightly and intelligently but they do so totally independently of our awareness and our belief.

There is no indication there is any intelligence - as in the property of a mind to acquire and use knowledge to solve problems - in our immune system. There is no sort of indication of intelligence in either its function or composition.

 

[Gene2memE]

I've just finished Plantinga's book again - "Where the Conflict Really Lies". This is supposed to be his final form of the EAAN. As I've tried to synthesize it to be able to teach it, I continue to be persuaded that it's a strong argument.

The argument seeks to show that you cannot rationally accept both naturalism and evolution because this pair of beliefs is self-defeating. Here's the argument:

1. The probability (P) of our cognitive faculties being reliable (R) given naturalism and evolution (N&E) is low.
2. Anyone who believes N&E and sees that P(R/N&E) is low acquires a defeater for R.
3. Anyone who acquires a defeater for R acquires a defeater for all of her beliefs, including N&E.
4. If by believing N&E one acquires a defeater for N&E then N&E is self-defeating and cannot be rationally accepted.
5. Therefore N&E cannot be rationally accepted.

So there you have it. You cannot rationally be an atheist and also believe in evolution. How do you respond to this argument?

I'm going to add another objection - even if the first part of P1 is correct, that doesn't mean that we cant come to true ideas or reliable comprehension of reality.

People have developed two entire edifices to the fact that humans come to faulty conclusions about things - namely the sciences and education.

The sciences are there to test our ideas about reality and see if they are correct or not.
Education is there to teach people the correct conclusions we've drawn about reality - among other things.

Also, the EAAN is not an apologetic for Christianity. Even if evolution were demonstrated to be false tomorrow, what would replace it would still be framed within methodological naturalism. The sciences cannot function any other way.

Also, there's a counter apologetic to the EAAN - shouldn't humans modeled in the image of God not have unreliable cognitive faculties? Afterall, what sort of omnibenevolent creator produces a sentient species with unreliable cognitive faculties?

 

[Nihilist Virus]

I've just finished Plantinga's book again - "Where the Conflict Really Lies". This is supposed to be his final form of the EAAN. As I've tried to synthesize it to be able to teach it, I continue to be persuaded that it's a strong argument.

The argument seeks to show that you cannot rationally accept both naturalism and evolution because this pair of beliefs is self-defeating. Here's the argument:

1. The probability (P) of our cognitive faculties being reliable (R) given naturalism and evolution (N&E) is low.
2. Anyone who believes N&E and sees that P(R/N&E) is low acquires a defeater for R.
3. Anyone who acquires a defeater for R acquires a defeater for all of her beliefs, including N&E.
4. If by believing N&E one acquires a defeater for N&E then N&E is self-defeating and cannot be rationally accepted.
5. Therefore N&E cannot be rationally accepted.

So there you have it. You cannot rationally be an atheist and also believe in evolution. How do you respond to this argument?

1. The probability (P) of our cognitive faculties being reliable (R) given naturalism and evolution (N&E) is low.

He fails to define "reliable." What does this mean? As long as this unreliability does not result in death before sexual activity, it is irrelevant to evolution. Show me animals in nature whose cognitive faculties are not "reliable." They've probably gone extinct. The vast majority of animals have "reliable" cognitive faculties and therefore the probability is high, not low, that we should have reliable cognitive faculties.

2. Anyone who believes N&E and sees that P(R/N&E) is low acquires a defeater for R.

A defeater? The probability of being dealt a straight flush is low. Should we then assume that no such hand can ever be dealt, no matter how many hands are dealt? You see the problem here, yes? I'll spell it out. How many species of animals exist? That's a lot of hands being dealt, isn't it?

3. Anyone who acquires a defeater for R acquires a defeater for all of her beliefs, including N&E.

True.

4. If by believing N&E one acquires a defeater for N&E then N&E is self-defeating and cannot be rationally accepted.

True.

5. Therefore N&E cannot be rationally accepted.

False.

 

[2PhiloVoid]

I've just finished Plantinga's book again - "Where the Conflict Really Lies". This is supposed to be his final form of the EAAN. As I've tried to synthesize it to be able to teach it, I continue to be persuaded that it's a strong argument.

The argument seeks to show that you cannot rationally accept both naturalism and evolution because this pair of beliefs is self-defeating. Here's the argument:

1. The probability (P) of our cognitive faculties being reliable (R) given naturalism and evolution (N&E) is low.
2. Anyone who believes N&E and sees that P(R/N&E) is low acquires a defeater for R.
3. Anyone who acquires a defeater for R acquires a defeater for all of her beliefs, including N&E.
4. If by believing N&E one acquires a defeater for N&E then N&E is self-defeating and cannot be rationally accepted.
5. Therefore N&E cannot be rationally accepted.

So there you have it. You cannot rationally be an atheist and also believe in evolution. How do you respond to this argument?

You don't want to know how I'd respond to this. Just leave it that, bro!