Plantinga's Evolutionary Argument Against Naturalism

[dakoski]

Hadn’t seen Plantinga’s Evolutionary Argument Against Naturalism as a thread (at least for a while) so thought it would be good to discuss.

Here’s the argument:

Premise 1: The probability of reliable cognition and reasoning is low or uncertain if evolution and naturalism are true.

Natural selection acts on hereditary traits that promote survival. Therefore, our cognitive and reasoning systems have not necessarily evolved to generate true inferences, but rather inferences that enhance our survival.

But isn’t the ability to generate true inferences by definition associated with greater probability of survival? Not necessarily, there are several reasons why this may not be the case. For example:

a) Error management theory argues that natural selection may favour avoidance of large risk at the expense of optimal logical inferences. An example atheists might like is that this theory can be used to support the high prevalence of false beliefs regarding theism, on the assumption that naturalism is true.

b) Neuroscience research suggests that higher serotonin is associated with over-optimistic bias. However, given the potential association between serotonin and depression, lower levels of serotonin may be associated with more accurate inferences but less adaptive.

c)For reductive materialists – human behaviour is determined by external factors as we do not have free will. In this context, its irrelevant to survival whether we are able to generate true inferences therefore there is no reason to think natural selection would select for reliable cognition and reasoning.

Premise 2: Anyone who believes that:
- naturalism and evolution are true
- naturalism and evolution are associated with a low or inscrutable probability of reliable cognition and reasoning
Have a defeater for their belief that their cognition and reasoning are reliable.

The obvious objection to this premise is that we know from experience that our cognition and reasoning are reliable. However this objection has a few limitations:

a) The argument is addressing the reliability of our cognition and reasoning – therefore we can’t use the conclusions of our cognition and reasoning to demonstrate the reliability of our cognition and reasoning (i.e. we’re engaging in circular reasoning)

b) The argument isn’t addressing the reliability of our cognition and reasoning given our experience, it’s addressing their reliability given the assumption that naturalism and evolution are true. The objection conflates these - they would first have to demonstrate the truth of naturalism for this objection to be valid.

Premise 3: Anyone who has a defeater for the belief that their cognition and reasoning are reliable – have a defeater for all their beliefs including naturalism. This follows from premise 2.

Premise 4: Anyone who believes both naturalism and evolution acquires a defeater for these beliefs. Therefore believing both naturalism and evolution is self-defeating and can’t be rationally accepted.

Question for debate:
Which premises do you agree or disagree with? Of course providing a rationale for accepting or rejecting the premises.

Some caveats:
1) Plantinga isn’t arguing that our cognition and reasoning are unreliable – that’s the point of the argument to show that naturalism is inconsistent with our experience of relatively reliable cognition and reasoning

2) Plantinga’s argument isn’t trying to refute evolution

[wiploc]

Hadn’t seen Plantinga’s Evolutionary Argument Against Naturalism as a thread (at least for a while) so thought it would be good to discuss.

Here’s the argument:

Premise 1: The probability of reliable cognition and reasoning is low or uncertain if evolution and naturalism are true.

There's no reason to think it higher if naturalism is false. What are the odds that a magic-throwing god would want our cognition to be reliable?

Put differently, in what percentage of god-infested possible worlds do we have reliable cognition? Is there any reason to suppose that, on average, cognition is more reliable in worlds with gods?

Premise 2: Anyone who believes that:
- naturalism and evolution are true
- naturalism and evolution are associated with a low or inscrutable probability of reliable cognition and reasoning
Have a defeater for their belief that their cognition and reasoning are reliable.

Anyone who believes in magic-throwing gods has many similar defeaters.

Are fossils evidence of an old earth, or are they just god's practical jokes? Is the doctrine of the Trinity patently false because it contradicts itself, or is it something theists are obliged to believe? Can it be both?

If you believe that gods can get away with contradiction, like being omnipotent while being unable to defeat iron chariots, or being possible-to-see while being not-possible-to-see, then you not only can't trust your perceptions, you can't trust your ability to reason. If you believe in gods, then logical arguments (or pseudo-logical arguments like the one this thread is about) should mean nothing to you.

Premise 3: Anyone who has a defeater for the belief that their cognition and reasoning are reliable – have a defeater for all their beliefs including naturalism.

Anyone who has a defeater for the belief that their cognition and reasoning are reliable also has a defeater for all their beliefs, including theism.

Premise 4: Anyone who believes both naturalism and evolution acquires a defeater for these beliefs.

Anyone who believes in theism acquires even stronger defeaters for that belief.

Therefore believing both naturalism and evolution is self-defeating and can’t be rationally accepted.

That recklessly overstates the case, in a way that has to make one wonder whether Plantinga is even interested in truth and logic. This may be a good place to mention that Plantinga claims he would believe in god regardless of what the evidence indicated.

The strongest conclusion Plantinga is entitled to would be something like this: Given that our perceptions and reasoning sometimes make errors, we should be alert for error. We should hold even our strongest conclusions with some degree of doubt. Evolution is one of our strongest most robust conclusions, and theism has no more support than any other form of wishful thinking, but the most rational people--and I am not one of them since I would continue to believe I know that gods exist regardless of any change in the evidence--would continue to hold that our belief in evolution--and our disbelief in gods--do not quite come to 100% certainty.

[dakoski]

[Replying to post 2 by wiploc]

Hi wiploc - yeah I think its a good question whether theism is consistent with reliable cognition and reasoning and we can get to that a bit later.

But this particular debate topic is whether naturalism is consistent with reliable cognition and reasoning - any views on Plantinga's premises?

That recklessly overstates the case, in a way that has to make one wonder whether Plantinga is even interested in truth and logic. This may be a good place to mention that Plantinga claims he would believe in god regardless of what the evidence indicated.

The strongest conclusion Plantinga is entitled to would be something like this: Given that our perceptions and reasoning sometimes make errors, we should be alert for error. We should hold even our strongest conclusions with some degree of doubt. Evolution is one of our strongest most robust conclusions, and theism has no more support than any other form of wishful thinking, but the most rational people--and I am not one of them since I would continue to believe I know that gods exist regardless of any change in the evidence--would continue to hold that our belief in evolution--and our disbelief in gods--do not quite come to 100% certainty.

I don't think this addresses his argument.

[Divine Insight]

Premise 1: The probability of reliable cognition and reasoning is low or uncertain if evolution and naturalism are true.

I see absolutely no reason at all to even remotely entertain his premise #1.

His arguments for this seem quite naive and uninformed. Humans in particular were able to advance to the top of the food chain precisely because we were able to comprehend and manage:

1. Tool Making.
2. The harnessing of natural resources:
2a. Harnessing fire.
2b. Making clothes to protect from the elements.
2c. Constructing homes again to protect from the elements, as well as from predators.
3. Having the ingenuity to outsmart other animals to become better predators ourselves.
4. And of course the biggie: Agriculture.

Of the above require rational reasoning and intellectual understanding.

So this already put his premise #1 to shame as far as I can see.

Premise 2: Anyone who believes that:
- naturalism and evolution are true
- naturalism and evolution are associated with a low or inscrutable probability of reliable cognition and reasoning
Have a defeater for their belief that their cognition and reasoning are reliable.

The obvious objection to this premise is that we know from experience that our cognition and reasoning are reliable. However this objection has a few limitations:

a) The argument is addressing the reliability of our cognition and reasoning – therefore we can’t use the conclusions of our cognition and reasoning to demonstrate the reliability of our cognition and reasoning (i.e. we’re engaging in circular reasoning)

b) The argument isn’t addressing the reliability of our cognition and reasoning given our experience, it’s addressing their reliability given the assumption that naturalism and evolution are true. The objection conflates these - they would first have to demonstrate the truth of naturalism for this objection to be valid.

I suggest the entire quoted block is basically a 'strawman' argument. He tries to argue that until we can show that naturalism is true we can't draw any conclusions. But if he's going to hold that argument, then it would need to also need to apply to any suggestions he's going to make concerning alternatives to naturalism. In other words, he would need to demonstrate the truth of his proposed theories for his objections to naturalism to be valid.

So his premise #2 is basically a strawman argument that tries to place the burden of proof on his opponent whilst supposedly freeing him from any need to prove his theory.

Premise 3: Anyone who has a defeater for the belief that their cognition and reasoning are reliable – have a defeater for all their beliefs including naturalism. This follows from premise 2.

Well, there you go. I've already showed that his premise #2 is a strawman premise so nothing of value can follow from it. This is a common error that many people make in arguments. They make a bad argument and then use their previous bad argument as a false premise for their next argument.

Premise 4: Anyone who believes both naturalism and evolution acquires a defeater for these beliefs. Therefore believing both naturalism and evolution is self-defeating and can’t be rationally accepted.

Just a continuation of the previous mumbo jumbo.

Question for debate:
Which premises do you agree or disagree with? Of course providing a rationale for accepting or rejecting the premises.

His very first premise was already clearly wrong. He only went downhill from there.

Some caveats:
1) Plantinga isn’t arguing that our cognition and reasoning are unreliable – that’s the point of the argument to show that naturalism is inconsistent with our experience of relatively reliable cognition and reasoning

But he didn't show that to be the case at all. This is why his arguments fail.

2) Plantinga’s argument isn’t trying to refute evolution

Well, his arguments weren't making any sense anyway so it really doesn't matter much what he was trying to show or refute.

Clearly his premise #1 is grossly false. If humans didn't acquire intellectual superiority over other animals then we wouldn't be any different from other animals. In other words we wouldn't have evolved to the top of the food chain.

Is Plantinga aware that we are a member of the Great Apes family of primates? Had we not evolved to a high level of tool usage we would be no different from all the other Great Apes.

Now if Plantinga is going to come back with saying that this is his very point, then I would simply suggest that this is not impressive since as humans we have only lived on this planet an extremely short period of time. If we consider the age of the earth to be 24 hours, modern humans have only existed for about 1 minute.



In terms of natural selection and evolution it makes sense that some creatures would have evolved naturally to obtain a fair degree of intelligence and comprehension.

And far more importantly, the idea that this was done by "design" makes no sense because if it was done by design we should have expected humans to have shown up far earlier.

Until Plantinga can offer a demonstration of his "theory" of how humans became intelligent (if he even has one) then, by his own criteria he's in no position to be making claims about it.

[dakoski]

[Replying to Divine Insight]

I see absolutely no reason at all to even remotely entertain his premise #1.

His arguments for this seem quite naive and uninformed. Humans in particular were able to advance to the top of the food chain precisely because we were able to comprehend and manage:

1. Tool Making.
2. The harnessing of natural resources:
2a. Harnessing fire.
2b. Making clothes to protect from the elements.
2c. Constructing homes again to protect from the elements, as well as from predators.
3. Having the ingenuity to outsmart other animals to become better predators ourselves.
4. And of course the biggie: Agriculture.

Of the above require rational reasoning and intellectual understanding.

So this already put his premise #1 to shame as far as I can see.

Plantinga isn't arguing that human's aren't capable of rational reasoning and intellectual understanding - so this doesn't address premise 1 regarding the consistency between naturalism and reliability of our cognitive processes.

I suggest the entire quoted block is basically a 'strawman' argument. He tries to argue that until we can show that naturalism is true we can't draw any conclusions. But if he's going to hold that argument, then it would need to also need to apply to any suggestions he's going to make concerning alternatives to naturalism. In other words, he would need to demonstrate the truth of his proposed theories for his objections to naturalism to be valid.

So his premise #2 is basically a strawman argument that tries to place the burden of proof on his opponent whilst supposedly freeing him from any need to prove his theory.

This is a misunderstanding - but its probably my fault for not making it clear enough.

The point as above is looking at the consistency of naturalism with the reliability of our cognition and reasoning. Its not addressing the consistency of our experience with the reliability of our cognition and reasoning - that's not a topic addressed in his argument. In fact, he argues given our experience he does think our cognition and reasoning are reliable.

Well, his arguments weren't making any sense anyway so it really doesn't matter much what he was trying to show or refute.

Clearly his premise #1 is grossly false. If humans didn't acquire intellectual superiority over other animals then we wouldn't be any different from other animals. In other words we wouldn't have evolved to the top of the food chain.

Is Plantinga aware that we are a member of the Great Apes family of primates? Had we not evolved to a high level of tool usage we would be no different from all the other Great Apes.

Now if Plantinga is going to come back with saying that this is his very point, then I would simply suggest that this is not impressive since as humans we have only lived on this planet an extremely short period of time. If we consider the age of the earth to be 24 hours, modern humans have only existed for about 1 minute.

Doesn't address his argument as far as I can see - but I may have missed what you mean.

In terms of natural selection and evolution it makes sense that some creatures would have evolved naturally to obtain a fair degree of intelligence and comprehension.

And far more importantly, the idea that this was done by "design" makes no sense because if it was done by design we should have expected humans to have shown up far earlier.

Until Plantinga can offer a demonstration of his "theory" of how humans became intelligent (if he even has one) then, by his own criteria he's in no position to be making claims about it.

Plantinga's argument here is that because natural selection acts on survival and reproductive success, not the reliability of our logical inferences, we can't assume that natural selection will lead to reliable cognitive faculties. Its possible, but we can't really know that. There are also examples given in the OP of circumstances where less optimal cognitive systems may be favoured by natural selection as they have potentially greater survival advantages.

Given this uncertainty, wouldn't agnosticism about the reliability of our cognition be warranted if we assumed naturalism was true?

[Divine Insight]

[Replying to Divine Insight]

I see absolutely no reason at all to even remotely entertain his premise #1.

His arguments for this seem quite naive and uninformed. Humans in particular were able to advance to the top of the food chain precisely because we were able to comprehend and manage:

1. Tool Making.
2. The harnessing of natural resources:
2a. Harnessing fire.
2b. Making clothes to protect from the elements.
2c. Constructing homes again to protect from the elements, as well as from predators.
3. Having the ingenuity to outsmart other animals to become better predators ourselves.
4. And of course the biggie: Agriculture.

Of the above require rational reasoning and intellectual understanding.

So this already put his premise #1 to shame as far as I can see.

Plantinga isn't arguing that human's aren't capable of rational reasoning and intellectual understanding - so this doesn't address premise 1 regarding the consistency between naturalism and reliability of our cognitive processes.

But he did argue that rational reasoning and intellectual understanding were not required for survival. Everything I listed clearly helped humans to survive.

Not only this, but Plantinga actually demonstrated a gross misunderstanding of evolution and natural selection here already. Evolutionary traits aren't chosen because some "consciousness" is evaluating whether something has survived or not. Evolutionary traits are chosen because of "actual" survival. Therefore everything I listed helps humans to actually survive. In fact, it's quite possible that if humans did not acquire these skills they may have very well died off as a species. There were other hominid species that did die off.

So didn't list these things just to imply that humans are indeed capable of reasoning. I listed them specifically because they are all example where reasoning can indeed contribute to survival. Something Plantinga was attempting to argue against. After all, that's the whole point of his argument. If he can't argue that reasoning doesn't contribute to survival then he doesn't have an argument.

I suggest the entire quoted block is basically a 'strawman' argument. He tries to argue that until we can show that naturalism is true we can't draw any conclusions. But if he's going to hold that argument, then it would need to also need to apply to any suggestions he's going to make concerning alternatives to naturalism. In other words, he would need to demonstrate the truth of his proposed theories for his objections to naturalism to be valid.

So his premise #2 is basically a strawman argument that tries to place the burden of proof on his opponent whilst supposedly freeing him from any need to prove his theory.

This is a misunderstanding - but its probably my fault for not making it clear enough.

The point as above is looking at the consistency of naturalism with the reliability of our cognition and reasoning. Its not addressing the consistency of our experience with the reliability of our cognition and reasoning - that's not a topic addressed in his argument. In fact, he argues given our experience he does think our cognition and reasoning are reliable.

But at this point the reliability of our cognition is already irrelevant to his argument because his original argument was based on the idea that reliable reasoning was not required for naturalism. So he was already wrong on that point.

Well, his arguments weren't making any sense anyway so it really doesn't matter much what he was trying to show or refute.

Clearly his premise #1 is grossly false. If humans didn't acquire intellectual superiority over other animals then we wouldn't be any different from other animals. In other words we wouldn't have evolved to the top of the food chain.

Is Plantinga aware that we are a member of the Great Apes family of primates? Had we not evolved to a high level of tool usage we would be no different from all the other Great Apes.

Now if Plantinga is going to come back with saying that this is his very point, then I would simply suggest that this is not impressive since as humans we have only lived on this planet an extremely short period of time. If we consider the age of the earth to be 24 hours, modern humans have only existed for about 1 minute.

Doesn't address his argument as far as I can see - but I may have missed what you mean.

He doesn't have any arguments that need to be addressed once his initial premise has been shown to be false.

In terms of natural selection and evolution it makes sense that some creatures would have evolved naturally to obtain a fair degree of intelligence and comprehension.

And far more importantly, the idea that this was done by "design" makes no sense because if it was done by design we should have expected humans to have shown up far earlier.

Until Plantinga can offer a demonstration of his "theory" of how humans became intelligent (if he even has one) then, by his own criteria he's in no position to be making claims about it.

Plantinga's argument here is that because natural selection acts on survival and reproductive success, we can't assume that natural selection will lead to reliable cognitive faculties. Its possible, but we can't really know that. There are also examples given in the OP of circumstances where less optimal cognitive systems may be favoured by natural selection as they have potentially greater survival advantages.

Given this uncertainty, wouldn't agnosticism about the reliability of our cognition be warranted if we assumed naturalism was true?

I don't see why. Just because things can survive without having achieved reliable cognition it doesn't follow that reliable cognition wouldn't naturally evolve.

I mean think about it. This would be like saying that since an amoeba can survive there is no rational reason to expect that anything should ever evolve with capabilities greater than an amoeba has. After all, what would be the point in evolving to greater capabilities when an amoeba is already surviving quite nicely on its own?

This is basically what Plantingas argument is based on. In other words, he's arguing that anything that isn't "necessary" for survival should be question as to why it would evolve.

But that's really not how natural evolution works at all. Natural evolution works by the simple principle that "anything that can happen will happen". And if whatever happens is capable of surviving then it will survive.

I think Plantinga is potentially clinging to a wrong idea of natural evolution, like as if it's only going to do whatever is necessary to survive and no more than this.

But there is nothing in the process of natural evolution that requires that traits and abilities that aren't necessary for survival can't also occur. As long as they don't pose a problem for survival and they "can" occur, then they will occur.

In fact, once this is realized this turns Plantinga's argument on its head.

In other words, Plantinga would need to demonstrate how cognitive reasoning would be detrimental to survival. If he can't demonstrate that, then he has no argument.

A process of natural evolution doesn't give a hoot if things evolve that aren't self-detrimental. Why would it? In fact a process of natural evolution doesn't even "know" anything. It has no clue what's going on. Things that can survive, do survive. Things that can't survive die out.

That's it period.

So there's nothing in natural evolution that would prevent cognitive reasoning from emerging. And as I had already pointed out, cognitive reasoning actually does contribute to survival anyway contrary to Plantinga's claim that it wouldn't.

Cognitive reasoning most likely evolved in humans for the same reason that Lions evolved from amoebas. In other words, once there were amoebas, according to Plantinga's arguments there would be no need to evolve any higher than that just to "survive" as an amoeba. Why bother evolving in to higher animals at all?

I just don't see where Plantinga's arguments make any sense.

Perhaps I'm missing something

But the bottom line for me is that cognitive reasoning in humans would be no different from a lion evolving to have fangs, claws and a coat of hair, or that birds would evolve wings to fly. Why bother with any of that when amoebas already had "survival knocked"?

There would be no reason to evolve any higher than mere survival according to Plantinga's arguments.

It seems to me that Plantinga just has a very wrong idea of what natural evolution is actually all about. We don't need to make an argument that everything that evolved was "necessary" for survival. All it needs to be it "not" detrimental to survival.

[wiploc]

The point as above is looking at the consistency of naturalism with the reliability of our cognition and reasoning. Its not addressing the consistency of our experience with the reliability of our cognition and reasoning - that's not a topic addressed in his argument. In fact, he argues given our experience he does think our cognition and reasoning are reliable.

And yet sometimes we're wrong. Which, according to his theory, means his god messed up, right?

In my view, Christians are wrong; in Plantinga's view, atheists are wrong. Why, if there is a god, would anybody be wrong?

Since error does happen, we know that there are no gods.

-

That's not a good argument, of course, but it is every bit as good as Plantinga's argument.

[Divine Insight]

The point as above is looking at the consistency of naturalism with the reliability of our cognition and reasoning. Its not addressing the consistency of our experience with the reliability of our cognition and reasoning - that's not a topic addressed in his argument. In fact, he argues given our experience he does think our cognition and reasoning are reliable.

And yet sometimes we're wrong. Which, according to his theory, means his god messed up, right?

Exactly. If our reasoning is so reliable then why are so many people in disagreement with each other? Especially when it comes to theology and knowing about something about a God?

I think philosophers often "imagine" that their reasoning is reliable, when in fact it isn't.

But obviously the reasoning of many scientists is reliable since their reasoning produced results that actually match up with reality and can be tested and verified.

So apparently some humans have reliable reasoning, and others do not.

[wiploc]

[Replying to post 2 by wiploc]

Hi wiploc - yeah I think its a good question whether theism is consistent with reliable cognition and reasoning and we can get to that a bit later.

But this particular debate topic is whether naturalism is consistent with reliable cognition and reasoning - any views on Plantinga's premises?

You having him saying that "The probability of reliable cognition and reasoning is low or uncertain if evolution and naturalism are true." That is only significant to his argument if that reliability would be higher on theism. So the fact that reliability has not been shown to be higher on theism is a full refutation of his argument.

Suppose I point out that, on naturalism, there was essentially zero chance that evolution would produce you. If my point is that I must know black magic, because how else can we account for the fact that evolution produced you against all odds, then you are entitled to point out that I haven't shown how the odds would be better if I knew black magic.

You would be entitled to argue that. It would be on point. You would be entitled to ignore any suggestion that we ought to delay that discussion until later because right now we are discussing the odds of naturalism producing exactly you. Because your point would not be an aside or a distraction, it would be a full refutation of my argument.

The essence of Plantinga's argument--even if it remains implicit--is that our mental state is more likely on theism than on atheism. Since he hasn't yet made that case, his argument fails.

That recklessly overstates the case, in a way that has to make one wonder whether Plantinga is even interested in truth and logic. This may be a good place to mention that Plantinga claims he would believe in god regardless of what the evidence indicated.

The strongest conclusion Plantinga is entitled to would be something like this: Given that our perceptions and reasoning sometimes make errors, we should be alert for error. We should hold even our strongest conclusions with some degree of doubt. Evolution is one of our strongest most robust conclusions, and theism has no more support than any other form of wishful thinking, but the most rational people--and I am not one of them since I would continue to believe I know that gods exist regardless of any change in the evidence--would continue to hold that our belief in evolution--and our disbelief in gods--do not quite come to 100% certainty.

I don't think this addresses his argument.

You have him saying, "Therefore believing both naturalism and evolution is self-defeating and can’t be rationally accepted." He wants us, like Pascal, to assume a dichotomy: Either naturalism is true, or Plantinga's god exists.

He implicitly argues that our minds are more likely if his god exists. He says our minds are much more likely to have resulted from his god than from natural causes. So much more likely that it is irrational to believe in naturalism.

To reach that conclusion, he would have to show that our minds would be likely to result from the existence of his god. He hasn't shown that. He doesn't have a case.

I showed the conclusion that he could have drawn, that a logical person would have drawn. I showed that in order to contrast it to the conclusion that Plantinga drew.

[Bust Nak]

[Replying to post 1 by dakoski]

Alternatively, one can affirm Plantinga’s argument and acknowledge the inherent unreliability of our senses as well as our minds. That's why optical illusions are a thing, that's why logical fallacies are a thing, that's why religions are a thing. We have to be extra careful not to fall into those traps. As such his arguments are not defeaters for naturalism/evolution, given we are indeed careful with our thinking on those topics.

If one was to argue that being extra careful doesn't help as even our best attempts at rationality is in itself unreliable, then the argument can be rejected out of hand for pragmatic reason, as we reject strict solipsism out of hand. The somewhat reliable capability of our senses and reasoning prowess, are taken for granted.