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

[dakoski]

[Replying to Bust Nak]

I think we've come to the stage where we won't really get much further now. I maintain that I think the assumptions of your worldview are incoherent which I think I've shown above. Also I think I've shown that your attempts to avoid the charge of logical incoherence ultimately aren't successful.

Not surprisingly, I imagine you will disagree with me on this. That's fine, so we'll have to agree to disagree. I only have very limited time every now and again to discuss on the forum so its now time to get back to other things.Thanks for the discussion.

That's what the two and bit points are for: animals with accurate senses are fitter than those with inaccurate senses; most organisms are bad at reasoning; optical illusion, common logical fallacies.

I’ve already addressed these point several times.
1) Plantiga’s argument is to do with reasoning, so it muddies the waters a little to focus on senses – I’ve been imprecise in my terminology so its not a criticism just a clarification
2) Why is it necessarily the case that accurate reasoning is more evolutionarily adaptive? Since many naturalists argue that all behaviour is simply a conditioned response to our environments and therefore that we don’t have free will, why would being able to reason be adaptive? If you disagree with reductive materialists, how would you refute them?
3) As I’ve said ad nauseam, since serotonin leads to optimistic bias there’s a strong argument that it’s evolutionary adaptive to not have reliable cognition.

I don't need to refute his premises as I agree with them. The problem is how you and Plantinga tries to portrait it as some sort of weapon, as we naturalists accept the conclusion of the argument as a feature, not a problem of naturalism.

You claim to accept the conclusion of Plantinga’s argument?
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.

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.

But you think the get out clause is to presuppose the validity of your reasoning whilst also affirming naturalism. Problem with this is that if you accept Plantinga’s premises then you accept that there is a logical incoherence between affirming naturalism and affirming the validity of our reasoning. Therefore, this calls into question your simultaneously presupposing that naturalism is true and that your cognition is reliable.

Your response is that you don’t need to justify your presuppositions. Which is half-true, as you say that's why we call them presuppositions. But that's also misleading,
clearly its not valid to include within your worldview two or more presuppositions that are inherently contradictory. To argue that 'its OK because they are presuppositions' is just special pleading.

If you accept Plantinga’s premises and the conclusions of his argument then you have to either abandon the presupposition that naturalism is true or the presupposition that your reasoning is reliable. Just because they are presuppositions doesn’t mean its OK for them to be contradictory.

But they are logically coherent though. Everything we see matches up with what we expect to see should these two assumptions are true, those two and a bit points are just a tiny taste of how great these two assumptions stick together.

And this here is the problem with Plantinga's argument, not with the argument itself mind you, but how it is presented as an argument against coherence of naturalism and accurate senses. You can't jump from the actual conclusion of Plantinga's argument (namely, there is no guarantee of accurate senses) to your conclusion that my assumptions are not logically coherent. That last jump is a non sequitur.

That is precisely the point of Plantinga’s argument, given naturalism is true we cannot presuppose that our cognition is reliable as the probability of that being the case is highly uncertain. Therefore it is logically incoherent to presuppose something you know is either untrue or highly uncertain given your other presuppositions.

Again, there is nothing circular there. Any circularity you see are your own strawman creation. Just have a little think about your own position, if Plantinga's argument actually works against naturalism, it can be tweaked slightly and work against supernatural creator - you have zero guarantee that a creator gave you accurate sense after all. Plantinga's argument doesn't work against naturalism, any more than arguments along the lines of "no guarantee you were created with accurate sense" work against a creator.

You argument for 'zero guarantee that a creator gave you accurate sense after all' may work with deism. But I don't claim to be a deist.

That’s where you miss the point:
- if naturalism is true, evolutionary adaptiveness is determined by my ability to survive and reproduce not my ability to generate reliable inferences. Therefore given naturalism you are correct you have zero guarantee that your reasoning will be reliable

-whereas in the Christian worldview, the purpose of my reasoning is that I may know and understand the world God has created and act as steward of it. This logically coheres with my assumption about the reliability of my reasoning. You can presuppose that this God doesn't want us to know and understand the world, but then you would be presupposing a different god.

[Divine Insight]

This argument is a little silly – if it was common for Christian’s to interpret the image of God as reflecting that we are omniscient then you might have a point. However, since I have never seen a Christian claim that then it is pretty obviously a strawman.

It's not strawman because I never claimed that you did.

I simply demonstrated that inconsistency of your argument. In fact, if you don't claim that humans are omnipotent then you've made my point. Because you are the one who claimed that we should have reliable cognition, because we are supposedly make in the image of God. Well duh? If that's your reasoning then we should also be omnipotent. But clearly you reject that idea. So there is there any strawman?

I never thought for one second that you would make such an utterly absurd claim. So my point is made the moment you accept that we are not omnipotent.

You’re also continuing to pursue the false antithesis between omniscience and reliability. If someone isn’t omniscient then their cognition is unreliable - this is just simply false. Do you believe yourself to be omniscient? If not, do you believe yourself to be incapable of valid inferences? Of course the answer to both questions is no.

And now YOU are creating a "stawman". I never made that argument.

All I did was point out that your argument that we should have reliable cognition because we were supposedly created in the image of a God fails. And it fails precisely because we don't have all the other characteristics associated with this God.

In short, you are claiming that we are made in God's image and then demanding that this only applies to extremely limited abilities. So your argument fails. Why should we accept that we were made in the image of any God when you, yourself, demand that we don't have the vast majority of attributes this God supposedly has?

You argument fails. Period.

You originally attempted to challenge Plantinga’s premises but I’ve responded to your arguments several times but rather than actually respond to my comments you continue to restate your conclusion without actually interacting with my critique and also continuing to restate strawmen arguments. So the conversation can’t really progress.

But I haven't made any strawman arguments. That's your false accusation toward me.

I've proven using the words you attributed to Plantinga's premise number one that his premise fails. And you haven't shown otherwise. His premise states right in it that if human cognition is not reliable then naturalism must be true. So that's HIS CONCLUSION, not mine.

Now, let's go back to your argument:

You argue that all humans are created in the image of God, and this is why we should expect them to have reliable cognition.

Well, there you go! If that's your argument then all humans should have precisely the same level of reliable cognition. Unless you now want to argue that some humans are created in the "image of God" more so than others.

But surely you can see where that would quickly become highly problematic.

So as far as I can see Naturalism is winning hands-down here.

Its frustrating, but also funny, that you continue to repeat this straw man.

What strawman are you talking about?

You clearly stated in your post # 47:

Again you don't appear to be familiar with Christian theology regarding humans being made in the image of God.

You are the one who is trying to argue that humans should have reliable cognition because they are created in the image of God. Yet you want to reject that humans should have any of the other characteristics of God.

So where is there any strawman?

All, I'm doing is pointing out that your argument fails.

Moreover, if you claim that humans have reliable cognition because humans are created in the image of God, then why should any humans have less than reliable cognition.

My point is that you would then necessarily need to argue that those individuals are "not" created in the image of God.

You can't have your cake and eat it too.

Either humans have reliable cognition because they are created in the image of God, or they don't.

Make up your mind. That's all I ask. Give me a consistent argument, not a self-contradictory one. I'll call-out self-contradictory arguments anytime they are given.

[Bust Nak]

1) Plantiga’s argument is to do with reasoning, so it muddies the waters a little to focus on senses...

Recall if you will, an earlier statement of mine: "senses and reasoning (I am just going to use one to refer to both from here onwards.)"

2) Why is it necessarily the case that accurate reasoning is more evolutionarily adaptive?

It's not necessarily so, I never made such a claim, I don't need that premise. It is however the case that accurate reasoning is more evolutionarily adaptive in certain scenarios.

3) As I’ve said ad nauseam, since serotonin leads to optimistic bias there’s a strong argument that it’s evolutionary adaptive to not have reliable cognition.

So what? It is irrelevant for the same reason above, I don't need evolutionary adaptive to have any sort of predisposition for generating reliable cognition.

You claim to accept the conclusion of Plantinga’s argument?

Yes, namely there is no guarantee that our senses are accurate given naturalism.

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.

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.

Right, and that's the problem there, not having a guarantee for our senses is not a defeater for the belief that our cognition and reasoning are reliable.

But you think the get out clause is to presuppose the validity of your reasoning whilst also affirming naturalism. Problem with this is that if you accept Plantinga’s premises then you accept that there is a logical incoherence between affirming naturalism and affirming the validity of our reasoning.

But I don't accept that there is a logical incoherence between affirming naturalism and affirming the validity of our reasoning though, because they are coherent and trivially so since naturalism is built upon the presumption that our senses are accurate.

Your response is that you don’t need to justify your presuppositions. Which is half-true, as you say that's why we call them presuppositions. But that's also misleading, clearly its not valid to include within your worldview two or more presuppositions that are inherently contradictory. To argue that 'its OK because they are presuppositions' is just special pleading.

Right, but that's moot since all of my presupposition are complementary.

If you accept Plantinga’s premises and the conclusions of his argument then you have to either abandon the presupposition that naturalism is true or the presupposition that your reasoning is reliable. Just because they are presuppositions doesn’t mean its OK for them to be contradictory.

Or I could point out that the actual conclusion is, and how it doesn't warrant your conclusion that there is some sort of logical incoherence between affirming naturalism and affirming the validity of our reasoning.

That is precisely the point of Plantinga’s argument, given naturalism is true we cannot presuppose that our cognition is reliable as the probability of that being the case is highly uncertain.

But that makes no sense what so ever. The point of Plantinga’s argument is that given naturalism is true then our cognition is not necessarily reliable as the probability of that being the case is highly uncertain. That in no way imply we cannot presuppose that our cognition is reliable.

You argument for 'zero guarantee that a creator gave you accurate sense after all' may work with deism. But I don't claim to be a deist... in the Christian worldview, the purpose of my reasoning is that I may know and understand the world God has created and act as steward of it. This logically coheres with my assumption about the reliability of my reasoning. You can presuppose that this God doesn't want us to know and understand the world, but then you would be presupposing a different god.

That's not a guarantee that the Christian God gave you accurate sense, you just have faith that he did. It could be your Christian God given inaccurate sense that lead you to believe that the Christian God wants you to understand the world.

[dakoski]

[Replying to Bust Nak]

Ok have time for a brief response.

1) You offered nothing new in defence - you're asserting that you presuppose your reasoning is valid given naturalism - even though you accept its highly uncertain that reasoning is valid given naturalism. You're happy to make what I would say is an unjustified assumption - and that's your prerogative. I'm sure if a theist presupposed something to be true, when according to the data and logic its uncertain or unlikely, then I'm sure you would also conclude that such an assumption is unjustified.

2) What is new is your attempt to show Plantinga's argument can be modified to show its logically incoherent to assume we have reliable reasoning given Christian theism.

That's not a guarantee that the Christian God gave you accurate sense, you just have faith that he did. It could be your Christian God given inaccurate sense that lead you to believe that the Christian God wants you to understand the world.

The problem here is that either you don't understand Plantinga's argument or you're deliberately setting up a straw man - I'm unclear which one. Plantinga is assessing the logical coherence of assuming naturalism to be true and our reasoning being reliable. To construct an alternative for Christian theism would require showing that if Christian theism is true it would be unclear if our reasoning is reliable.

You're argument for logical incoherence rests on the assumption that the Christian God is a liar. That may be your opinion, but your opinion about the Christian God is irrelevant, as the question is whether the Christian worldview is logically coherent.

Its very easy to refute your assumption that the Christian worldview assumes God is a liar:
'so that by two unchangeable things in which it is impossible for God to lie, we who have taken refuge would have strong encouragement to take hold of the hope set before us.' Hebrews 6:18

So your argument fails. Sorry I probably won't have time for any other responses.

[Bust Nak]

1) You offered nothing new in defence - you're asserting that you presuppose your reasoning is valid given naturalism...

No no no. I am not asserting that all. Read previous my posts more carefully: I asserted that I presuppose my reasoning is valid full stop. I asserted (and demonstrated, if I may add) that naturalism is logically consistent with said presupposition. A distinct position from the one your are suggesting. I was very explicit and vocal that you've strayed into strawman territories. I called you out before and here you are, with the very same strawman.

2) What is new is your attempt to show Plantinga's argument can be modified to show its logically incoherent to assume we have reliable reasoning given Christian theism.

Again, no. I merely pointed out that Plantinga's argument can be modified to show its there is no guarantee that a Christian God gave you accurate reasoning. That in no way implies it's logically incoherent to assume you have reliable reasoning given Christianity. This was an analogy to show you that Plantinga's argument can only serve to show that there is no guarantee that nature gave us accurate reasoning. That in no way implies it's logically incoherent to assume we have reliable reasoning given naturalism.

The problem here is that either you don't understand Plantinga's argument or you're deliberately setting up a straw man - I'm unclear which one. Plantinga is assessing the logical coherence of assuming naturalism to be true and our reasoning being reliable. To construct an alternative for Christian theism would require showing that if Christian theism is true it would be unclear if our reasoning is reliable.

Right, if Christian theism is true it would be unclear if our reasoning is reliable. What you think is Christian theism is merely what your senses tell you, which may not be accurate. For all you know, actual Christian theism could says God is a trickers who gave you inaccurate senses.

You're argument for logical incoherence...

Again. Not my argument. I merely pointed out there is no guarantee that your senses are accurate given Christianity. I said nothing of logical incoherence, indeed, I explicitly denied such a thing - Not having a guarantee of senses does not in itself imply logical incoherence.

Its very easy to refute your assumption that the Christian worldview assumes God is a liar:
'so that by two unchangeable things in which it is impossible for God to lie, we who have taken refuge would have strong encouragement to take hold of the hope set before us.' Hebrews 6:18

First of all, that's exactly what a lying God would tell you, "believe me, I am not lying, all the best people know it." Next and perhaps more importantly, if God gave you inaccurate senses, you could be reading Hebrews 6:18 incorrectly. For all you know the actual text could say "I, Lord God, is free to lie, for you have no way of verifying it with your inaccurate senses. I am tricking you to think Hebrews 6:18 says I can't lie right now. Such fun, such irony."

The point being, to use the assumption that Christianity is what your senses report Christianity to be, as the foundation of an argument that your senses are accurate, is a circular argument. At best you can say Christianity is consistent with the presumption that our senses are accurate. And that puts you in the same boat as me, who is saying naturalism is consistent with the presumption that our senses are accurate.

So your argument fails. Sorry I probably won't have time for any other responses.

No worries, I've made my points.

[dakoski]

[Replying to Bust Nak]

I had persisted as I was looking forward to your attempt to reverse the Plantinga argument – but not unsurprisingly you’ve not taken on board my critique of your argument and instead went for a rinse and repeat. The most persuasive and effective critique's are those where someone understands the argument well and then attempts to refute an accurate version of that argument. In the era of echo chambers such responses are few and far between.

I think both your attempt at defending the logical coherence of naturalism and your attempt to try to show the logical incoherence of theism show you’ve not really understood Plantinga’s argument. I’ve clarified a number of times but you’ve not really taken them on board as you appear to have taken an off the shelf response so have no flexibility to adapt it once misunderstandings are identified.

[Bust Nak]

I had persisted as I was looking forward to your attempt to reverse the Plantinga argument – but not unsurprisingly you’ve not taken on board my critique of your argument and instead went for a rinse and repeat.

Hold your horses, your critique amounted to a Bible verse saying God can't be a liar - I responded extentively to that counter argument. In short, you are using the word of God to support the claim that God cannot lie, that's circular. You also have no idea of what the Bible says without the presumption that you have somewhat accurate senses. How is this not taking your critique on board? The ball in firmly in your court.

I think both your attempt at defending the logical coherence of naturalism and your attempt to try to show the logical incoherence of theism...

No no no, how many times do I have to tell you, I am not trying to show the logical incoherence of theism? I stated and I quote: "I merely pointed out that Plantinga's argument can be modified to show its there is no guarantee that a Christian God gave you accurate reasoning. That in no way implies it's logically incoherent to assume you have reliable reasoning given Christianity."

Read my post carefully, you've repeatedly produced strawman versions of my argument, despite multiple complains. Quit it.

I’ve clarified a number of times but you’ve not really taken them on board as you appear to have taken an off the shelf response so have no flexibility to adapt it once misunderstandings are identified.

I've responded point by point to each of your critique and you often repeat the same argument again or worse, present a strawman. I called you out on strawman and you double down on it. How many times have I stated that I was not trying to justify my sense by appealing to naturalism? How many times have I stated I was not arguing against the coherency of accurate senses with Christianity? Ironically, you are the one who has not taken my clarifications on board, talk about the lack of flexibility to adapt it once misunderstandings are identified. Look in the mirror.

[dakoski]

[Replying to Bust Nak]

This issue I have is that this latest response continues to show a fundamental misunderstanding of Plantinga's argument.Given that I've taken the time to provide extensive clarifications - this is disappointing.

A prerequisite for an effective critique of an argument is to be able to demonstrate that you understand it. I'm afraid after this amount of time you've failed to show that.
I judge that the utility associated with providing further clarification is unlikely to justify the further time required to provide these clarifications.

I'm afraid I now only have the time to provide substantive responses to posts that attempt to critique an accurate reflection of Plantinga's argument. Your current post doesn't meet that criterion.

[Bust Nak]

[Replying to post 58 by dakoski]

You know, the time you spent on telling me that you don't have time might have been better spent responding to my points. You basically wasted the 300+ words trying to have the last word. You don't get to have the last word when you are the one trying to disengage from the debate.