Thursday, April 23, 2009

Plantinga's Evolutionary Argument Against Naturalism MP3 Audio

Philosopher Alvin Plantinga's evolutionary argument against naturalism purports to show that metaphysical naturalism, when combined with contemporary evolutionary accounts of the origin of human life, is self-defeating. (wikipedia) It is worth a listen. His outline can be found here or in PDF.

Full MP3 Audio here from Veritas.org.

Enjoy.

24 comments :

Lee said...

"evolutionary argument against naturalism"???

That really doesn't make any sense to me, but I will give a listen.

Lee

Lee said...

From the link

"Now for the argument that it is irrational to believe N&E: P(R/N&E) is either low or inscrutable; in either case (if you accept N&E) you have a defeater for R, and therefore for any other belief B you might hold; but B might be N&E itself; so one who accepts N&E has a defeater for N&E, a reason to doubt or be agnostic with respect to it."Is that suppose to make sense to me?

Can someone please translate into 'words'

Or maybe the podcast is better.

Lee

Leslie said...

This is actually one of the strongest arguments, in my opinion, against naturalism.

I'll see if I can help, Lee...

P(R/N&E) means = what is the probability (P) that our cognitive faculties are reliable (R) given metaphysical naturalism and evolution N&E.

His argument is that the probability (P) in this case would be either low or unknowable, thus, regardless of which way it goes, the reliability of our cognitive faculties (R) is defeated - you can't flat out trust them. If you have a defeater for R, then you also have a defeater for any belief (B) you might hold. But the idea that naturalism and evolution (N&E) are true is a belief. Thus, his conclusion - you have reason to doubt N&E, or at best to be agnostic about it.

To put it simply, he argues that if naturalism and evolution are true, then we have little reason to trust our cognitive faculties (something which even Darwin recognized). But if our cognitive faculties are unreliable, then any belief we might hold would be left with severe reason for doubt - including the belief that naturalism and evolution are true. Evolution could be true, but not naturalistic evolution.

I do think the audio is better. Plus Plantinga is enjoyable to listen to ... he has a goofy sense of humor.

Eric said...

Leslie, that's a nice summary of Plantinga's argument. All I would add (to give a sketch of an answer to the most obvious questions any summary would raise) is that, (1) given naturalism, it's not even clear whether any causal relationship whatsoever obtains between our beliefs and our behavior, and (2) even if such a relationship does obtain, the reason we shouldn't expect evolution to produce true beliefs is that evolution acts on our behavior, not on our beliefs, and that the 'correct' behavior (in terms of fitness and reproduction) is consistent with any number of beliefs, most of which are false.


"Plus Plantinga is enjoyable to listen to ... he has a goofy sense of humor."

He's had me laughing out loud a number of times. I once heard a panel discussion which included him and Bill Craig. Craig was speaking about some technical issue concerning the interpretation of the Hebrew Scriptures, and went on to say that no one on the panel was an expert in that area. Plantinga spoke next, opening with, 'As Bill said, I'm not an expert in this area, but I'm not going to let that stop me.'

Lee said...

Thanks Leslie

Makes a lot more sense when the letters are explained.

Still, I think it is a rubbish argument FOR anything.

He is basically saying, I think, that you cannot believe in reality.

Deny reality and what do you have?

I cannot see how you can jump to conclusions of God once you deny reality.

I will listen to the podcast next week on the way to work.

Cheers

Lee

Lee said...

the reason we shouldn't expect evolution to produce true beliefs is that evolution acts on our behaviorThis is why I do not trust my senses, and thank goodness for science and it's method. :-)

Interesting also, what you are saying is an argument why we should not believe ourselves when we say 'I believe in God because of such and such a feeling or observation'

We should use scientific method to test our ideas.

Lee

Leslie said...

Lee,

We should use scientific method to test our ideas.No, that's the precisely the problem. Your rationality is part of your cognitive faculties. From the article:

"If (naturalistic) evolution is true, then our cognitive faculties will have resulted from blind mechanisms like natural selection, working on sources of genetic variation such as random genetic mutation. And the ultimate purpose or function (Churchland's 'chore') of our cognitive faculties, if indeed they have a purpose or function, will be survival - of individual, species, gene, or genotype. But then it is unlikely that they have the production of true beliefs as a function."

Your cognitive faculties affect everything, including science. So what you think is proving one thing - what you think is logical and rational - could in reality be proving nothing of the sort, unless you can trust your senses. You must first have a valid reason to trust your senses, and blind mechanisms working on natural selection for the "purpose" of propagation is no valid reason to trust your senses. Naturalism simply cannot produce a good reason for me to trust my senses, be that rationality or emotions or whatever else. A God, on the other hand, who gives me rationality, would be far more consistent.

Plantinga is not arguing that you should deny reality. He's arguing that if all you have is naturalistic evolution, you lack a good reason to trust your cognitive faculties, whether they are telling you about science or anything else. In other words, if you're a naturalist, you should be agnostic concerning your interpretation of reality. That would be most consistent.

Lee said...

Hi Leslie,

Lee We should use scientific method to test our ideasLeslie .No, that's the precisely the problem. Your rationality is part of your cognitive faculties.So how do you test your ideas and ensure they are correct (or not wrong)?

Do you know something better than the scientific method to test reality – or are you happy with the ideas you get from something you already agree can be faulty – i.e. our human thoughts/feelings.

This is rather confusing?

At best Plantinga would be throwing stones at idea, but offering nothing in its place.

So I've nothing to reject from Plantinga, nothing is on offer it would seem.

Your cognitive faculties affect everything, including science. Fine, but until you give me something better – it is the best I’ve got.

”…unless you can trust your senses”I don’t trust my senses, and I have been shown this via science.

History is full of examples of our senses getting it wrong – and science getting it ‘right’ (or showing us where are common sense is wrong at least)

A God, on the other hand, who gives me rationality, would be far more consistent.That’s nonsense… you have just argued that you cannot trust your senses, that you cannot trust logic and reason – and so you trust God?

It doesn’t follow…

Why can’t you just be mistaken about God?

If you cannot trust yourself, as you argue, because the natural process could corrupt your thoughts and conclusions – how is it than you can conclude God?

Your argument is flawed – and besides, if my conclusions are right (and your thoughts about natural evolution is right also) then you are just as likely to be mistaken about God.

And is my reasoning - since God is more improbability (adding an extra assumption and unknown) the natural explanation without God fits into all that we have already agree is observed.

Plantinga is not arguing that you should deny reality. He's arguing that if all you have is naturalistic evolution, you lack a good reason to trust your cognitive faculties, whether they are telling you about science or anything else. Fine – but as I have said, Plantinga isn’t providing anything to replace it with. Using his own arguments is reason enough not to believe in gods – we cannot trust our senses – so what are we left with?

In other words, if you're a naturalist, you should be agnostic concerning your interpretation of reality. That would be most consistent.I think I am a naturalist, or at least I have not been shown anything else, but I am not sure about being agnostic about reality – or indeed my interpretation of it.

I will stick with the best one I have, until you can provide something to replace it with. I am not commited to it though.

Oh and to finish on the obvious - even IF you could disprove A, it does not prove B now does it :-)

Take care

Lee

Matthew said...

Still, I think it is a rubbish argument FOR anything.It's not an argument FOR anything.

Plantinga argues that you can't both rationally believe in evolution and naturalism, that's all.

Leslie said...

I should add that the God part was thrown in by me - Plantinga doesn't really say that if I remember correctly. As the title indicates, his argument is not FOR anything - it is simply against naturalism.

Here's the thing, Lee ... you keep coming back to saying that science does the job. But how do you know that? You trust your senses. You trust that you have some degree of rationality that actually delivers you a correct interpretation of reality. In other words, you trust your cognitive faculties.

The question is simply this - why do you trust your cognitive faculties? Plantinga here is saying that given naturalism and evolution, the probability is quite low, or perhaps unknowable, that our cognitive faculties are reliable. So even if you say science works, that argument still relies upon the assumption that your cognitive faculties are reliable. You can't just point things out and say "See? It works!" because that is begging the question.

My point about bringing in God was this: I do trust my cognitive faculties, and I think you should too. But why? If it's naturalism and evolution, that's not a good reason. But if there is a perfect God who created me and wanted me to have reliable faculties, then I would expect that would be reliable. Thus, that is the most consistent way.

But again, as Matthew pointed out, Plantinga is not arguing FOR God. He's simply saying that naturalism doesn't cut it. And he's right.

Matthew said...

Here's the thing, Lee ... you keep coming back to saying that science does the job. But how do you know that? You trust your senses. You trust that you have some degree of rationality that actually delivers you a correct interpretation of reality. In other words, you trust your cognitive faculties.That's the part of the argument that makes it interesting, that Plantinga argues "it's impossible to defeat this defeater".

It's a complex argument, but I think it's not bad.

Lee said...

Hi Leslie,

Plantinga doesn't really say that if I remember correctly. As the title indicates, his argument is not FOR anything - it is simply against naturalism. Then, as I said, until something better is provided I will have to used the best that is to offer.

Here's the thing, Lee ... you keep coming back to saying that science does the job. But how do you know that? Let me see…. It got men to the moon, satellites to Jupiter, Saturn, Neptune, Uranus – actually all the planets come to think of it (even Pluto is a few years)

It has increased the average life expectancy of humans from around 30 years to 70 years, it has given us TV, computers, airplanes, cars and loads of leisure time compared to our cavemen friends.

Oh, and the internet…

Science seems to work for me – or do you have a better idea?

You trust your sensesNo I do not – I have said this already. I trust me to make mistakes :-)

You trust that you have some degree of rationality that actually delivers you a correct interpretation of reality.I said it seems science works – do you disagree with this?

In other words, you trust your cognitive faculties. I don’t think I do, since I said I do not trust my senses.

However logic and reason has provided the scientific method – the best method (and since you have not offered a replacement – you seem to agree with this yourself.)

The question is simply this - why do you trust your cognitive faculties? I trust repeatable empirical evidence – does that help?

Plantinga here is saying that given naturalism and evolution, the probability is quite low, or perhaps unknowable, that our cognitive faculties are reliable. And the argument is flawed.

So even if you say science works, that argument still relies upon the assumption that your cognitive faculties are reliable.I don’t think it does – it relies on repeatable empirical experimentation not just thinking about it

I think this makes you wrong doesn’t it?

You can't just point things out and say "See? It works!" because that is begging the question. But the Christian can say “Look, it must be God because I don’t understand”?

There does seem to be a conflict in reasoning somewhere...

You are saying the only way we can know anything is if God exists, and you don’t think that is begging the question or circular reasoning?

My point about bringing in God was this: I do trust my cognitive faculties, and I think you should too. But why? Indeed, since I have already said I don’t trust myself for good reason :-)

But if there is a perfect God who created me and wanted me to have reliable faculties, then I would expect that would be reliable. Thus, that is the most consistent way. No – and here is something I don’t get – all the evidence is for evolution and the Big Bang (and I could bore you with some of the details) Yet you seem to wish to deny all this evidence just because it points away from your understanding of God.

Why and on what grounds? If God did exist, why would He want you to do this?

But again, as Matthew pointed out, Plantinga is not arguing FOR God. I suggest he has a hidden premise of God :-)

If not naturalism, then what? Supernaturalism?…. And so the hidden is not so hidden now is it :-)

He's simply saying that naturalism doesn't cut it. And he's right.Wrong – his argument is flawed and is circular – and Plantinga has not been able to replace it WITH anything even IF I accept his premises (which I do not)

Now here’s a question - IF God, why do we think as we do, why do we reason as we do? Why shouldn't we use the brains God gave us (as you assume)?

If the reasoning and logic God gave us shows the universe is 13.7 billions years old and evolution from the simple to the complex resolves an ancient riddle - then why should we deny this?

How can you be so certain on your type of God, or what He wants?

Here’s another question (and more on topic)

How did Plantinga come to his conclusions? – did he use his cognitive abilities? If so, and Plantinga believes his cognitive abilities are reliable, isn’t he already assuming his conclusions are true?

Doesn’t this make it a circular, and meaningless argument?

I think so

Take care

Lee

Lee said...

Hi Matthew

It's a complex argument, but I think it's not bad.I think it is just a bad one - rather circular as I have just argued above.

Lee

Chad said...

You wrote:

"I don’t think I do, since I said I do not trust my senses."

However, you also wrote:

"I trust repeatable empirical evidence"

This is where the confusion, from my perspective, seems to be. My question is simple this:

How can you trust your examination of the "empirical evidence,” if at the same time you "do not trust your senses."

In my view, it would seem you would need to trust your senses in order for your examination of the empirical evidence to really mean anything.

Thank you Lee

Leslie said...

Lee,

I mostly want to ignore the God factor for now. As I said I threw that in (my apologies for bringing it in at this point - it's my fault), but it's not really the main point I'm trying to make, and it's certainly not what Plantinga is saying. The question at hand is whether naturalism does the job - we can discuss why I think God would be more consistent (i.e. alternatives) after this.

And at the point of naturalism, you are still repeatedly begging the question:

Let me see…. It got men to the moon ........... Science seems to work for me – or do you have a better idea?However logic and reason has provided the scientific method – the best method... I trust repeatable empirical evidenceAll of these points rely upon you trusting your cognitive faculties. How do you know that we got to the moon? How do you know we're really living longer? How do you know that the so-called repeatable empirical data is really empirical or is really being repeated? Ultimately - how do you know that what you are experiencing is reality?

All of your examples rely upon the idea that your cognitive faculties are reliable. At this point you disagree:

I don’t think it does – it relies on repeatable empirical experimentation not just thinking about it

I think this makes you wrong doesn’t it?
Again, no - you are missing something big here. Repeatable empirical experimentation is still based on the foundation of reliable cognitive faculties. The definition of empirical from Merriam-Webster: "originating in or based on observation or experience." So for it to be empirical you have to trust your cognitive faculties, unless you use something other than your cognitive faculties for observation/experience.

Plantinga gives a good example of how this issue could play out by a little thought experiment. Imagine a rabbit which has evolved in such a way that it thinks tigers are female rabbits. In order to mate with what it thinks are female rabbits, it flees into the distance as fast as possible. Likewise it thinks female rabbits are tigers, and in order to get to safety, it mates with them. Assuming the rabbit is fast enough to get away, and virile enough to produce offspring, that particular set of genetic information will get passed on. Eventually you have a breed of rabbits who, though having horribly incorrect interpretations of reality, still manage to survive. And assuming the rabbit could talk, it would even argue that "it works!" And it would be right - it does work - just for all the wrong reasons.

This is the factor that you have to work with. Ultimately, you still have to deal with the fact that your interpretation of everything in the real world (including science) is based upon the functioning of your cognitive faculties. But things could still "work" and appear to go in a direction that verifies your beliefs, without actually being true. If all you have is naturalistic evolution, then you don't really have a good reason to trust your cognitive faculties.

You say that Plantinga is wrong - that P(R/N&E) is not low. Why? As Matthew points out, there's no defeater for this defeater, but if you would like to offer a defeater for this defeater then I would be quite happy to consider it.

How did Plantinga come to his conclusions? – did he use his cognitive abilities? If so, and Plantinga believes his cognitive abilities are reliable, isn’t he already assuming his conclusions are true?

Doesn’t this make it a circular, and meaningless argument?
Plantinga doesn't have to assume that his cognitive faculties are reliable to make this argument. He only has to stay within the realm of the logic we use. So he could say that given the logic that we use (which may or may not be reliable), his argument is valid.

Besides, his argument is not that his cognitive faculties are reliable - i.e. that is not his conclusion. His argument is that R is incompatible with N&E.

Science seems to work for me – or do you have a better idea?You keep bringing up this issue of wanting a better method - a better alternative. But I do not have to have an alternative to discuss whether or not a current method is not working. If I have a car stuck in the mud, and me and one other guy keep trying to push it out to no avail, I don't have to have a way to get the car out of the mud to know that what we're doing isn't cutting it. So again, let's just set aside the issue of alternatives for now and ask whether or not naturalism is cutting it. I really think we need to deal with this issue before we can have a meaningful discussion on alternatives anyway.

Matthew said...

Lee, listen to the lecture again. I think you misundestood Plantinga on several points.

Lee said...

Hi Chad,

This is where the confusion, from my perspective, seems to be.Sorry for the confusion.

My question is simple this:The simple questions are normally the hardest to answer I have found :-)

How can you trust your examination of the "empirical evidence,” if at the same time you "do not trust your senses."Ah, I see the confusion…

What I mean is that I know that both my ‘common sense’ and eyes can be fooled. Hence I do not trust them straight away.

‘common sense’ tells me the Earth is flat and the Sun orbits us - my education tells me otherwise of course.

‘common sense’ tells me if I drop a large heavy cannon ball and an egg from a tall building, the cannon ball will hit the ground first… again, experience (and education) tells me otherwise.

As for not trusting my eyes – this is why we have optical illusions and magicians can make a living.

I don't think I am saying anything too shocking am I?

In my view, it would seem you would need to trust your senses in order for your examination of the empirical evidence to really mean anything.To a point yes, but only after re-evaluation of my senses and the observation. I do not just trust my senses out of hand. I know they are flawed.

Does that make more sense?

Lee

Lee said...

Hi Leslie

I mostly want to ignore the God factor for now. As I said I threw that in (my apologies for bringing it in at this point - it's my fault), but it's not really the main point I'm trying to make, and it's certainly not what Plantinga is saying.Fair enough – but I think you will be ignoring Plantinga hidden premise :-)

The question at hand is whether naturalism does the job - we can discuss why I think God would be more consistent (i.e. alternatives) after this. And I have said all along (I think) that if not naturalism – what else? (Hence the hidden premise of supernaturalism from Plantinga)

You don't seem to think this is an important point I am making?

An analogy from science

I know, for a fact, that Einstein’s theory of relativity is WRONG!!!
(You heard it here first folks)

So, what should I do?

Say I know nothing about gravity?

Start jumping off tall building because our knowledge of gravity is wrong?

Of course not, it is the best model that we have for gravity – until something comes along to better it, I am stuck with it.

My point here is, until you can demonstrate something better than naturalism – I’m stuck with it also.

You want to claim supernaturalism – them prove it, show it, take me to 'supernaturalism logic' and reason it for me please.

I will wait… what I cannot understand though is this, once you accept supernaturalism, nothing can be disproven, shown to be true and everything is possible.

I would not know if I was coming or going :-)

And at the point of naturalism, you are still repeatedly begging the question: I have to ask, what question am I begging precisely?

All of these points rely upon you trusting your cognitive faculties. I just replied to Chad on this – I think the confusion is how much trust I have in my ‘cognitive faculties’. Since I do not trust them 100%, I think this means I doubt them.

Maybe we are just talking degrees of trust and where I draw the line.

How do you know that we got to the moon?AAAARRRGGHHHH Moon Hoax talk – stone the non-believer, stone them!!!! :-)

How do you know we're really living longer? How do you know that the so-called repeatable empirical data is really empirical or is really being repeated? Ultimately - how do you know that what you are experiencing is reality? How do I know I am not a brain in a jar?

Aren’t we getting a little off-topic?

All of your examples rely upon the idea that your cognitive faculties are reliable. At this point you disagree:I am saying I cannot trust them out of hand – in the end I have to assume that I am me, looking out at the world, in a universe full of stuff and it follows repeatable laws/rules. If not, anything is possible and I cannot know anyway.

I could be a brain in a jar – but I have no reason to believe that, or to prove it true or false.

So what else can I do?

Again, no - you are missing something big here. Repeatable empirical experimentation is still based on the foundation of reliable cognitive faculties.And a working theory to interpret the observations I guess I forgot to add.

Plantinga gives a good example of how this issue could play out by a little thought experiment. Imagine a rabbit which has evolved in such a way that it thinks tigers are female rabbits. In order to mate with what it thinks are female rabbits, it flees into the distance as fast as possible. Likewise it thinks female rabbits are tigers, and in order to get to safety, it mates with them. Assuming the rabbit is fast enough to get away, and virile enough to produce offspring, that particular set of genetic information will get passed on. Eventually you have a breed of rabbits who, though having horribly incorrect interpretations of reality, still manage to survive. And assuming the rabbit could talk, it would even argue that "it works!" And it would be right - it does work - just for all the wrong reasons. Aren’t you just splitting hares… :-)

Sorry.

I think you are just playing with words a rabbit never heard of.

Also, doesn’t your analogy work the same way for quick breeding Catholics?

Their ideas aren’t ‘more right’, they just have more babies to call Catholics?

This is the factor that you have to work with. Ultimately, you still have to deal with the fact that your interpretation of everything in the real world (including science) is based upon the functioning of your cognitive faculties.Fine with me – I also have a lucky coin to keep aliens away… it must work since have you ever seen an alien?

I really do think we are getting away from the main point, but hey-ho.

But things could still "work" and appear to go in a direction that verifies your beliefs, without actually being trueI agree – I think this is why we have fundamentalist Christians who think they know science… but I am not sure if that is your point?

If all you have is naturalistic evolution, then you don't really have a good reason to trust your cognitive faculties.Fine – I think I already said (once or twice) that I do not trust them, but it is all I have to go on, so I will do the best I can.

I could be wrong and in reality we both could be brains in a jar next to one another on a shelf.

Worth thinking about? Probably not…


You say that Plantinga is wrong - that P(R/N&E) is not low. Why?Firstly, Plantinga has no justification to invoke a probability argument. To what does he compare his probability to? It is meaningless.

As Matthew points out, there's no defeater for this defeater, but if you would like to offer a defeater for this defeater then I would be quite happy to consider it.Can you refresh my memory with the argument being made?

Plantinga doesn't have to assume that his cognitive faculties are reliable to make this argument. He only has to stay within the realm of the logic we use. So he could say that given the logic that we use (which may or may not be reliable), his argument is valid.I’m not so sure, but I am running out of time tonight to discuss this in depth.

You keep bringing up this issue of wanting a better method - a better alternative. Yes

But I do not have to have an alternative to discuss whether or not a current method is not working.Actually you do if you want me to change my position.

Unless you can suggest a better idea, it is the best we have and that’s it really.

Fine if it isn’t perfect – I will wait until something better comes along :-)

I really think we need to deal with this issue before we can have a meaningful discussion on alternatives anyway.OK – refresh my memory about the issue.

You don’t like naturalism because it doesn’t have a place for gods? Of course not, surely not… :-)

I will repeat, even if you could prove A wrong, it does not prove B.

Lee, listen to the lecture again. I think you misundestood Plantinga on several points.You are probably right… but I know you guys can put me straight

Take care

Lee

Chad said...

Hello Lee,

I appreciate you taking the time to explain your thoughts. Your reply certainly helps me understand your comments more clearly.

You and I agree on numerous points. I agree that a common sense “first impression,” if you will, should be evaluated for it’s validity.

Further, I agree that when one is faced with an apparent illusion or magic trick, he or she should certainly not jump to the conclusion that what they saw was real. Natural explanations should be considered first.

I also agree, as illustrated above I hope, that one should not trust their senses out of hand. Great points!

However, I think that we are still begging the question.. I believe that to realize the above points, one would have to trust his “cognitive faculties,” to come to that conclusion.

It seems that for one to benefit from their experience and education, he or she would have to trust in their processing abilities in order to profit from experience and education.

Further, for one to reasonably evaluate and test their conclusions, wouldn’t he or she have to trust their reasoning at some point?

Thank you Lee. I appreciate your time and your sense of humor.

Take care

Lee said...

Hi Chad,

I appreciate you taking the time to explain your thoughts. Thanks for talking to me as well.

Your reply certainly helps me understand your comments more clearly. Phew… I just wish I understood what I said now.

You and I agree on numerous points. I agree that a common sense “first impression,” if you will, should be evaluated for it’s validity. Hooray :-)

Further, I agree that when one is faced with an apparent illusion or magic trick, he or she should certainly not jump to the conclusion that what they saw was real. Natural explanations should be considered first. It is the interpretation of such an observation that is important here…

As James Randi has said of ‘someone’, “He might be bending spoons with his mind, but if he is, he is doing it the hard way”

The point being, the supernaturally can never truly be ruled out, neither can aliens – but the simpler explanation is normally the correct one.

I also agree, as illustrated above I hope, that one should not trust their senses out of hand. Great points! Thanks :-)

HoweverDarn… I was doing so well until the ‘however’

I think that we are still begging the question.What question am I begging?

I believe that to realize the above points, one would have to trust his “cognitive faculties,” to come to that conclusion. OK – I give in. For a moment (and for sake of argument) I trust my cognitive faculties – now what?

It seems that for one to benefit from their experience and education, he or she would have to trust in their processing abilities in order to profit from experience and education. I think we have moved into ‘how do I know anything’ territory. This could be fun.

Time for me to learn philosophy is it?

I’m only science trained – if I can kick it, I like to believe it.
(And I’ve kicked many a castle wall just to prove it existed – my wife though I was mad, but I was just checking was my response. Windsor castle was the last castle kicking experiment I did – so you can trust me it exists)

Further, for one to reasonably evaluate and test their conclusions, wouldn’t he or she have to trust their reasoning at some point?Yes, but I don’t have a major problem with that. I trust myself a little, just not 100% and only as far as I can. As I said, I could be a brain in a jar - how would I know?

Now here is the problem I see with.

Firstly, it’s all quantum… at the quantum level I know nothing for certain – only probability. This causes me problems when it comes to knowledge and provides a little uncertainty into my life :-)

Hence, I cannot 100% trust myself.

Secondly, here is the problem for me with the supernatural conclusion (which is what is being pushed by Plantinga is it not?)

I would know even less for certain.

I would have to trust my senses even less – common sense tells me apples fall when dropped from trees. If supernatural weirdness exists as Plantinga claims, the apple is just a likely to one day fall up and not down.

Ah wait I hear you cry, Plantinga knows it is a reasonable God that has laws and stuff – but how does he know this? The problem remains, if supernatural – anything is possible isn’t it? Isn't that how water got turned to wine and all that?

Take care

Lee

Leslie said...

I don't feel like I'm getting anywhere here, so I'm going to take my leave of this particular convo. I'll close with a brief conclusion.

You do not have to trust every aspect of your senses to trust your cognitive faculties. When I say you trust your cognitive faculties, I mean, you believe that you can know certain things. You trust them enough to claim some kind of knowledge. This is what Plantinga is dealing with. He is not talking about emotions, or first impressions, or all those things you bring up. I don't care, for the purpose of this discussion, whether or not you trust your emotions or impressions or whatever. I care whether you trust yourself enough to do science. If you do, then you are guilty of trusting your cognitive faculties (I say guilty, though I am, of course, glad that you do trust them - I trust them as well).

The point is this, in order to trust them enough to even claim that anything works, or to do science, or math, or make any claims at all, you need some good foundation for trusting them. Plantinga's argument is simply that blind, purposeless forces acting through chance mutations and natural selection isn't enough of a reason to trust your cognitive faculties on any point, since the only concern (if indeed there is a concern) of Darwinian evolution is survival, and survival is not reliant upon truth - in fact, it could be just the opposite.

You may not like it, but the fact is, if survival is the only thing that has driven humanity to this point, then we have little reason to feel confident in our knowledge of anything, be it practical or theoretical. If I want to truly say that I can trust my cognitive faculties enough to make trustworthy claims about reality (or to do science, or a host of other things), I'm going to need a much firmer foundation than naturalistic evolution can provide.

Lee said...

Hi Leslie,

Thanks for your time, it was fun – I see don’t know how you base your certainty, but hey-ho.

I will end this just giving a link I fell upon last night.

Stephen Law is a bit of a philosopher at some Uni, I have a couple of his books, and read his blog from time to time.

This link is on plantinga – I am surprised I didn’t find it sooner so to speak.

http://stephenlaw.blogspot.com/2009/03/new-draft-plantinga-paper.html

Take care

Lee
PS
Chad, if you still have the energy, I could go another round or we could call it a draw :-)

Chad said...

Hello Lee,

I laughed when I read your “one or two more rounds” comment. Have you been watching Rocky Balboa again? :-)

As far as trusting our own reason, I believe I have said all I can. For me, to conclude that you can’t trust your reason (or that you can), you must trust your reason to come to that conclusion. When I used the phrase “begging the question,” I choose my words poorly, admittedly. What I mean by that is that one is assuming that which they are denying to draw a conclusion.

Finally, to be honest, I have a hard time understanding statements like, “As I said, I could be a brain in a jar- how would I know?” I will grant you, for the sake of discussion, that you COULD be a brain in a jar; however, I think the better question is, “Do I have any good evidence that suggests that I am a brain in a jar?”

I once had the opportunity to meet WLC at a conference. A gentleman beside me asked him a similar question about “could God have…” and Dr. Craig’s reply seems to be relevant here:

“I suppose God could have, however, I suppose God could have created me 5 minutes ago with a lifetime of memories and a full stomach, but I have no good reason to believe that He did.”

Point being, this type of thinking leads to absurdness that don’t seem to be consistent with reality as we observe it.

Could I be on the dust ball that Horton is carrying around? I guess it's a possibility; but it doesn't seem to be a very probable one.

Thank you again Lee for the respectful and thoughtful discussion. I will most likely end our interaction here unless compelled to do otherwise. I'm not sure there is much more to say.

Take care

Lee said...

Hi Chad,

Have you been watching Rocky Balboa again?Only the first 4…

Ding, Ding - round 265 :-)

I think the better question is, “Do I have any good evidence that suggests that I am a brain in a jar?”I agree 100% with you here.

My point of raising the ‘brain in the jar’ (or ‘the matrix’ if you want a more modern account) is that we cannot be certain really of anything.

I might not be certain of my senses or my reasoning, but this is all I have to go on. I will let them lead where there lead.

The difference seems to be that most theists here are not happy with that conclusion/reasoning and so then assert that I require God.

Why?

So, continuing your logic and reasoning (which I agree with) “Do I have any good evidence that suggests there is a god?”

No more than I have that I might be a brain in a jar, so why jump to any conclusions?

I think we are back at the beginning of the discussion and we have gone full circle.

Here is a good place to pause as you say.

Thanks for your time… I’m sure I will be causing trouble on another thread here on this blog in the near future – so I hope to see you around.

Take care

Lee

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