This is a blog to discuss philosophy, chess, politics,
C. S. Lewis, or whatever it is that I'm in the mood to discuss.
Does Planting really think beliefs are formed by natural selection?Do Notre Dame shoot students who put down wrong answers on their examination papers?
'....after all, the whole point of the argument is to show that if evolutionary naturalism is true, then very likely we and our cognitive faculties are not reliable.'Does Plantinga mean that we cannot sense these demons which exist and are attacking our senses and reasoning?Plantinga claims that for each species, it is 'very likely' that they did not win the lottery of evolution granting a species reliable cognitive faculties.So what?Millions of people can take part in a lottery.No matter which person you consider , it is very unlikely they will win the lottery.Does this mean that nobody will win the lottery?There are billions of species,past and present.The chances of a species developing reliable cognitive faculties through evolution must be a billion to 1 against.So what is Plantinga's point?On a theistic viewpoint, where is Plantinga's non-question begging proof that this alleged God decided to grant reliable cognitive faculties to Homo sapiens and not to Rattus rattus?Did Homo sapiens just get lucky and be this alleged god's chosen species?So why can't Homo sapiens just get lucky and have reliable brains formed by natural selection, something Plantinga cannot rule out as having happened?
Does Planting[a] really think beliefs are formed by natural selection?No. Obviously.He says, though, that one who believes in naturalistic evolution ought to hold that position; since on that account evolution is what drives the development of all biological features and behavior.
Plantinga raises the obvious objection to his thesis that any animal that evolved a strong tendency to believe false things would quickly fail. But I can't make head or tail of his attempted refutation of this objection.For example he writes:But what about their beliefs? These beliefs have been produced or caused by that adaptive neurophysiology; fair enough. But that gives us no reason for supposing those beliefs true. So far as adaptiveness of their behavior goes, it doesn't matter whether those beliefs are true or false.That makes it sound like beliefs are a decoration in addition to adaptive neurophysiology. But, of course, beliefs are a core component of our neurophysiology. For those organisms capable of belief, belief is a massive driver of action. And if too many of those beliefs are false then those actions are going to lead the organism to fail. The fact that the beliefs are the part of an adaptive neurophysiology is a massive reason for supposing them to be true.One reason I have faith in my senses is that I have survived 57 years assuming that they mostly tell the truth.This is so obvious I am sure properly qualified philosophers must have dealt with it somewhere?
Not really, Frank. Plantinga has been misunderstanding mathematics, evolutionary biology, and cognitive science for the last fifteen years. *Shrugs*
Ah, the much vaunted Plantinga.rayndeon is right. Plantinga simply doesn't understand evolutionary biology. The value in intelligence is that it makes you adaptable to new rules in much less than a generation. Learning rules and making correct inferences has a huge survival advantage. And you can't fake that with irrationality.But apparently Plantinga doesn't understand philosophy either. Why assume you're rational in theism? Theory: God made us irrational and tries to deceive us. Good luck proving this theory wrong.If the assumption of rationality is cost-free in theism, it can be cost-free in naturalism too.
'He says, though, that one who believes in naturalistic evolution ought to hold that position; since on that account evolution is what drives the development of all biological features and behavior.'I see.So it is just a strawman Plantinga is knocking down.Presumably evolution is what gave circus seals the ability to balance a ball on its nose.Wait! Balancing a ball on its nose would give seals no survival advantage in the wild.So God must have done it.
These criticisms are not so good. Plantinga's argument focuses on the possible belief-action relations open to what he calls ordinary naturalists (i.e., naturalists who have some commitment to basic evolutionary principles). He observes that it's not easy for a naturalist to avoid being an a semantic epiphenomenalist (Bob Cummins claims it's the received view) or a simple epiphenomenalist of some sort. And it is true, it's difficult to avoid that commitment. But if epiphenomenalism of some sort is true then, appearances nothwithstanding, one's beliefs have no causal role in behavior: they are counted among the epiphenomena. But then there could be no selection pressure toward having true beliefs, since having such is not going to help you survive. So, if you are an ordinary naturalist then you should conclude that it's improbable that most of your beliefs are true.Obviously, Plantinga's argument is much more subtle than that. He considers in addition to epiphenomenalism, the possibility that your beliefs are efficacious but maladaptive and the possibility that they are efficacious and adaptive. His argument is pretty interesting and powerful under each of these assumptions. He also bothers to offer weaker and stronger conclusions from EAAN. In any case, a decent, unrebutted objection to the evolutionary argument is not easy to come by. Plantinga has addressed several criticisms (from some heavy hitters) online here, http://philofreligion.homestead.com/files/alspaper.htm, if you happen to be interested.
Mike,Frankly, I have to admit that a lot of what Plantinga says is baffling. For instance, you mention (as Plantinga does) that Plantinga endorses the idea of adaptive false beliefs. But, as we know from any cursory understanding of genetics, this whole line of reasoning is just entirely irrelevant and the probability calculations Plantinga tries to make are also entirely-wrong headed. Plantinga brings up the idea of adaptive false beliefs in the sense that we could have thoroughly false beliefs that are nonetheless adaptive i.e. I think the tiger is friendly but would like me if I ran away from it - hence, I avoid the predator and have a false adaptive belief.This is multiply flawed of course. First of all, evolution does not directly select for particular beliefs. There are no genes for particular beliefs. Instead, evolution can and does select for particular cognitive faculties that can produce beliefs. So, changes to the CF globally affect the organisms ability to form beliefs. And our beliefs are highly dependent - not independent. Certainly, it is logically possible that there are a myriad of false beliefs that form adaptive behavior - but not very probable. You're going to have to have a *different* false belief each time for each particular situation to ensure its adaptivity - yet, a single true belief will tend to be adaptive in a *variety of situations*. We are goal-oriented rational animals, and our goals depend upon a large number of beliefs all in tandem. Even the most inordinately simple tasks (i.e. driving to work) depend on a myriad of beliefs, all working in tandem, all of which we rely upon as true. The probability of there being a myriad of false beliefs, all of which *are* independent, produced by some hypothetical CF is so vanishingly improbable that the probability that my beliefs are largely reliable is almost indistinguishable from unity. The idea is that variation affects CFs globally and there is going to have to be some mechanism that ensures a large number of false *independent* beliefs are adaptive - but the latter is vanishingly improbable, hence, Plantinga's probability thesis is simply false. I said the following at Exapologist's blog:"*beliefs are not heritable*. Generalized belief-forming *systems* are. Your belief, for instance, that 0.9 repeating equals 1 or that there is a computer in front of you is not inherited. Instead, the faculties that allow these sorts of beliefs to develop are inherited. This makes the idea that viable nonreliable cognitive faculties being not merely likely, but *much more likely* than reliable cognitive faculties positively implausible. Mutations to a population will *globally* affect the cognitive faculties in question. So, for example, it would be like causing a random change in the entire circuitboard of a calculator, rather than some particular circuit path. Clearly, the probability of a viable, unreliable cognitive faculties forming in this manner are vanishingly low. Consider the sorts of things rational entities must do: They judge distance. They have a sense of time. They feel. They weigh possible outcomes before deciding on a choice. In any choice whatsoever is a medley of enormously complex neural patterns and processes. If none of them reflected reality, there is an extremely good chance that the population in question would die out, and die out fast. Because the genes in question are *general*, this does not allow for the heritability of *specific* genes that result in false but adaptive *beliefs*. Generalized belief systems, if they are to promote the fitness of a species, must be reliable, or the population will quickly die out. If a species had a faulty general sense of smells (assuming they do not have other compensating sensory methods), they would not be able to detect predators and such a trait would likely not be fixed in the species."Likewise, I don't really understand his point about the content of a belief and the neurophysical structure. According to most reductive physicalists, that NP-structure just is the belief. Also, the causal processes of evolution are responsible for bringing about the cognitive faculties that form such neural patterns, so there would seem to be a causal connection here. I don't know - maybe I'm misunderstanding Plantinga here.
The point I'm trying to make, in summary, is that - philosophical problems aside - Plantinga's problem doesn't even arises since Plantinga's problem is predicated on a misunderstanding of genetics, evolutionary biology, and cognitive science. A myriad of false adaptive beliefs is extremely unlikely - likewise, beliefs are not selected for by evolution; cognitive faculties are.
What is Plantinga's argument?If evolution is true, we ought to expect many people to have false beliefs, so making quiz programmes on TV more interesting than if everybody always gave the correct answer?ALMEIDASo, if you are an ordinary naturalist then you should conclude that it's improbable that most of your beliefs are true.CARRSo what?Naturalists know that a bird sees 3 people go into a hide, and sees 2 come out and then thinks the hide is empty.This enables them to watch birds.It is very likely that most species are bird-brained, just as it is very likely that most people do not win the lottery.So is Plantinga arguing that lottery winners are impossible, because each and every person in the lottery is unlikely to win it?And Plantinga knows for a fact that beliefs about evolution were not formed through natural selection.Not even Dawkins shoots people who confuse a genotype with a phenotype.So what is Plantinga's argument?There isn't one. His argument is the truism that ,if evolution is true, then human beings would not have evolved true beliefs.Of course they didn't evolve true beliefs. Nobody is born believing that the differential of sin x is cos x. Scientific beliefs are not formed by natural selection.Of course, Plantinga's world view is that there exist malevolent demons who can attack his reasoning and senses.So his world view suffers from these problems in extremis.
When I wrote 'evolved true beliefs', I should have written 'evolved beliefs which are guaranteed to be true.'By the way, with his God-given reliable cognitive faculties, does Plantinga really think the best thing for a man in his 70s to do when faced with a tiger is to try to run away from it? :-)Running away from a tiger must be the best thing to do,because Plantinga knows his cognitive faculties are reliable and they tell him to run away from the tiger.Pity that such behaviour is only likely to alert the tiger to the fact that you think you are tiger-food....Perhaps Plantinga's cognitive faculties are not very reliable after all...Perhaps because they were evolved rather than being a gift from God....
PLANTINGAPerhaps Paul very much likes the idea of being eaten, but when he sees a tiger, always runs off looking for a better prospect, because he thinks it unlikely that the tiger he sees will eat him. Or perhaps he thinks the tiger is a large, friendly, cuddly pussycat and wants to pet it; but he also believes that the best way to pet it is to run away from it. . . . or perhaps he thinks the tiger is a regularly recurring illusion, and, hoping to keep his weight down, has formed the resolution to run a mile at top speed whenever presented with such an illusion; or perhaps he thinks he is about to take part in a 1600 meter race, wants to win, and believes the appearance of the tiger is the starting signal; CARRThis is all very interesting.Plantinga is claiming that if evolution is true, we should expect it to produce people who make perfectly logical and valid arguments, but whose premises for those arguments are of dubious truth.So why is that person's cognitive faculties not reliable?I can give you the names of umpteen supporters of the Ontological Argument who produce perfectly logical and valid arguments, but whose premises for those arguments are of dubious truth.Are all those people automatically to be declared as having unreliable cognitive faculties simply because they argue from premises whose truth is controversial?That seems rather drastic, yet Plantinga seems to think that a person's cognitive faculties are unreliable, even in cases where he himself claims they are making logical deductions, but from premises that they don't realise are not true.PLANTINGA'It begins from certain doubts about the reliability of our cognitive faculties, where, roughly, a cognitive faculty--memory, perception, reason--is reliable if the great bulk of its deliverances are true.'CARRIt appears Plantinga thinks that if you ask him questions about his past, he will get 'the great bulk' of them true, because his memory is reliable.I guess Plantinga can remember the contents of every meal he has ever eaten, and what he wore on every day of his life,and how many dogs were in the room when he ate those meals.Or perhaps not....'The great bulk' of what Plantinga's memory delivers to him is 'I can't remember', 'I've forgotten', 'It was a long time ago.'So Plantinga's memory would fail his own definition of a 'reliable cognitive faculty.'And his 'perception' would also fail the test of a 'reliable cognitive faculty', especially if he removed his glasses, which were not given to him by God, and are there to correct what his alleged god designed.So what the hell is Plantinga's argument?If evolution is true, then we should expect to forget almost all details of our life, and have worse eyesight than a cat?But we do forget almost all details of our life and have worse eyesight than a cat.So evolution is true after all.
Certainly, it is logically possible that there are a myriad of false beliefs that form adaptive behavior - but not very probable.For my money, most of these posts are way too long. I can't see it: why try to make 25 points per post?Anyway, you engage Plantinga in the quotation above. On the contrary, there are countless ways for false belief to produce adaptive behavior. What we want is to act in the right way. It does not matter what we believe, so long as those beliefs produce the right sorts of behavior. There are countless possibilities here. As a matter of fact, most of the beliefs of most people you meet will be false, but not wildly false. It is perfectly easy to meld false belief with adaptive behavior.First of all, evolution does not directly select for particular beliefs. There are no genes for particular beliefs.This is a straw man. Plantinga never says (nor would he say) that individual beliefs are selected for. Indeed, his entire argument is for the claim that naturalism + evolution make it unlikely that one's cognitive faculties are reliable.. . . yet, a single true belief will tend to be adaptive in a *variety of situationsOk, this displays the problem. Your beliefs will not be adaptive unless belief, in general, is causally related to behavior. What helps you to survive is what YOU DO, not what you believe. If belief is properly causally related to action, then there a greater chance of true belief having survival value. But Plantinga argues--rightly, as far as I can see--that naturalists cannot make a good case for the right kind of connection.
Hi Mike,On the contrary, there are countless ways for false belief to produce adaptive behavior.Undoubtedly. It's just not very likely for them to arise.Indeed, his entire argument is for the claim that naturalism + evolution make it unlikely that one's cognitive faculties are reliable.Why then do his examples treat them as if they do? Take for instance his example of Paul and the tiger. He continually mentions different *adaptive* beliefs, as if evolution worked on beliefs. If Plantinga says, rightly, that evolution does not select for individual beliefs - where does he get the evolutionary justification for the idea that evolution can have it as such that one's beliefs are generally false but adaptive. Perhaps he'll appeal to some idea of a cognitive faculty that produces false adaptive beliefs - I don't know - there's no indication I see in Naturalism Defeated or Warranted Christian Belief that he's talking in just a broad way. But - anyway, the same criticisms I made will apply, since my criticisms centered around the idea of cognitive faculty that generally produced false adaptive beliefs to be likely.But Plantinga argues--rightly, as far as I can see--that naturalists cannot make a good case for the right kind of connection.Why not? Practically everything you do strongly depends on a medley of beliefs, even the most inordinately simple tasks. How could beliefs not be related to action? Humans are goal-oriented creatures - rational animals - and even the most simple tasks depend on a large number of beliefs: a large number of interpretative process of sensory inputs, a large number of post-sensory interpretation, sense of time, prediction and extrapolation via reliance on past experience and analogical reasoning, and a lot of other things - all of which require particular beliefs. Now, one might argue that such adaptive actions can systemically arise without the accompanying true belief - and that's certainly logically possible - but the entire point of my criticisms earlier were that it is vanishingly improbable.
I should make a correction to the above - I don't think it's probable for *systemically* false belief to generate adaptive behavior. Many, though not most, of our beliefs have nothing to do with adaptivity and their truth or falsity is to be known in the ordinary way - the ordinary methods of evidence and reasoning requiring that our reasoning process itself be generally reliable. So, like Plantinga, there's a sort of general, fundamental reliability here I'm talking about. For instance, my belief in Platonism or fictionalism is irrelevant to my survival - but the base reasoning processes I use to reach either Platonism or fictionalism or what have *are* relevant to my survival.
So what is Plantinga's argument?ALMEIDAYour beliefs will not be adaptive unless belief, in general, is causally related to behavior. CARRBut Plantinga gave examples of beliefs which WERE causally related to behaviour and pointed out they were false beliefs.So what is Plantinga's argument?is he really trying to prove that the odds of any given species (say Homo Sapiens) developing 'reliable cognitive faculties' are billions to one against?This is the same argument as telling a lottery winner that they cannot believe they have won the lottery because the chances of anybody having a winning ticket are very low.
ALMEIDaIf belief is properly causally related to action, then there a greater chance of true belief having survival value.CARRWhy?Do the faculty at Notre Dame shoot students who believe that the Pope is Protestant?Out of Plantinga's world, who believes that scientific knowledge evolved through natural selection?
PLANTINGA Suppose I believe that I have been created by an evil Cartesian demon who takes delight in fashioning creatures who have mainly false beliefs (but think of themselves as paradigms of cognitive excellence): then I have a defeater for my natural belief that my faculties are reliable.CARRBut Plantinga DOES believe that there are demons who delight in working evil by deceiving human beings.Adding the qualifier 'was created by those beings', is simply a sleight of hand to disguise the fact that Plantinga's world view suffers from the alleged problems of naturalism, and then further insurmountable problems on top. I can simply remove Plantinga's fig-leaf to leave bare the nakedness of his claim that theism provides a basis for his belief that his memory works more often than not. Suppose I believe that I have been attacked by an evil Cartesian demon who takes delight in shaping creatures who have mainly false beliefs (but think of themselves as paradigms of cognitive excellence): then I have a defeater for my natural belief that my faculties are reliable.Yes, Plantinga does now have a defeater for his claim that his memory will deliver a 'great bulk' of true memories of what he did every day in the past.A more obvious defeater is that Plantinga's unaided memory and perception are not reliable.Which is why he wears glasses and keeps diaries.
Why not? Practically everything you do strongly depends on a medley of beliefs, even the most inordinately simple tasks. How could beliefs not be related to action?Yes, actually they do. But were naturalism true, they would not. You have to keep what is actually the case (Plantinga believes that most of our beliefs are mostly true) from what would be the case were naturalism to hold (Plantinga believe they would not be true). If we suppose epiphenomenalism is true, then though it seems ot you like your beliefs are causally related t oyour actions, they aren't. It is a little like what would be the case were determinism true. It would seem to you like you are free, when in fact you're not.I say,On the contrary, there are countless ways for false belief to produce adaptive behavior.You say,Undoubtedly. It's just not very likely for them to arise.That's just question-begging, isn' it? You just assert the conclusion you'd like to arrive at. I point out that there are many ways that X could occur, you say "yes, bit it is unlikely that it will". This is like saying, sure, there are undoubtedly many ways for the fair die to come up non-6, but it is unlikely that it will.
MIKEYes, actually they do. But were naturalism true, they would not. You have to keep what is actually the case (Plantinga believes that most of our beliefs are mostly true) from what would be the case were naturalism to hold (Plantinga believe they would not be true). CARRNo.Plantinga says they would be unlikely to be true.Presumably,just as it would be unlikely for any named species to win the lottery of developing reliable brains through evolution.And if it is unlikely for any named species to have won the lottery of developing reliable brains through evolution,Plantinga concludes that no species can believe it has won the lottery of developing reliable brains through evolution.The last step needs some work on it....
MIKEPlantinga believes that most of our beliefs are mostly trueCARRWhat are Plantinga's beliefs about what he had for breakfast on each of every day he lived?Why does Plantinga say that our cognitive faculties are reliable, when he can't rely on his memory?Plantinga should go to Las Vegas if he thinks his beliefs about what number the roulette ball will end up on are 'mostly true'.
Mike: If we suppose epiphenomenalism is true, then though it seems ot you like your beliefs are causally related t oyour actions, they aren't.What makes Plantinga think that naturalism entails that epiphenomenalism is true? As far as I see, he doesn't - he draws out four mutually exclusively and jointly exhaustive possibilities, all of which seem available to the naturalist i.e. (a) epiphenomenalism (b) content epiphenomenalism (c) maladaptive causally efficacious beliefs and (d) adaptive causally efficacious beliefs. He has replies to all of them. That's just question-begging, isn' it? You just assert the conclusion you'd like to arrive at. I point out that there are many ways that X could occur, you say "yes, bit it is unlikely that it will". This is like saying, sure, there are undoubtedly many ways for the fair die to come up non-6, but it is unlikely that it will.It's not question-begging because I'm referring you to criticisms I already made - not asserting the contrary without elaboration or defense.
What makes Plantinga think that naturalism entails that epiphenomenalism is true? As far as I see, he doesn'tHe doesn't think the relation is entailment, certainly. He thinks it is the most likely candidate for naturalists and, as Cummins points up, it is the received view among naturalists. Taking into account the other possiblities, I don't find his estimate (roughly .45, I think) for Pr(R/ N&E) to be implausible. Perhaps the inscrutability conclusion is more plausible still. In either case, the naturalist who tracks the argument has a defeater.
Plantinga's argument is the dampest of damp squibs.The latest issue of 'Skeptical Inquirer' discussed evolution ,and posed the question 'Suppose the human species has simply not been able to think of the correct theory which explains all this data better than natural selection does. Is that possible?'And the answer in the article was , yes, it was possible.There could be a correct theory out there which human beings just can't grasp. It might be beyond our powers ever to think of the correct theory.After all, many scientific theories in the past have been replaced by other theories. There is no guarantee that current theories are correct.So what is Plantinga's argument when naturalists are perfectly happy with the idea that they might be wrong?
I'm proud to be the first anonymous poster on this thread. I don't know if anyone above has already made the contribution I shall try to make, since I haven't read all 25 of the verbose posts above, but at any rate, here goes:It seems to me that Plantinga’s argument may lead us to the very kind of “deep and pervasive skepticism” that he claims evolutionary naturalism leads us to. The evolution of our cognitive faculties is pretty well established; there’s plenty of evidence of it. According to Plantinga, we can avoid the skepticism inherent in evolutionary naturalism if God created humans in His image (by means of evolutionary processes or otherwise). If God guarantees that our cognitive faculties reliably produce true beliefs, we can avoid the skepticism of evolutionary naturalism. But the supposition that we were created in God’s image is much more contentious than the evolution of our neurophysiology. So it seems that the burden is on Plantinga to demonstrate that we were created in God’s image. But how can we know that we were made in God’s image? Is there an agreed upon set of evidence that would confirm Plantinga’s view? How would one collect evidence for Plantinga’s view? Presumably, we would do so with the use of our cognitive faculties. If we use our cognitive abilities to establish that God created us in His image, we’ve begged the question. So, Plantinga might be stuck in the same kind of skepticism he accuses evolutionary naturalism of leading us to.
Steven Carr,I don't have time to respond point by point just now (and I'm not sure I could), but if you want to accuse Plantinga of attacking a straw man, then please don't also commit the straw man fallacy yourself. It only makes you look like a complete fool.You say:"What are Plantinga's beliefs about what he had for breakfast on each of every day he lived?Why does Plantinga say that our cognitive faculties are reliable, when he can't rely on his memory?Plantinga should go to Las Vegas if he thinks his beliefs about what number the roulette ball will end up on are 'mostly true'."I presume Plantinga doesn't actually have belief about what he had for breakfast on each day of his life. Nor does he have beliefs about where the rouletter ball will end up.Guesses are not equivalent to beliefs. I think quite a number of your posts commit the straw man fallacy. That's why I so seldom bother to respond to your comments.Happy days,Steve
So Steve's defense of Plantinga's memory being a 'reliable cognitive belief' is that almost always it produces ZERO beliefs about Plantinga's past.How reliable is that? It is never wrong because it just doesn't produce anything at all.I guess a broken watch produces reliable beliefs about the time, because we can then claim we have no beliefs about the time, and so have absolutely zero false beliefs.STEVENor does he have beliefs about where the rouletter ball will end up.CARRStrange. Plantinga can't tell you he believes the roulette ball will end up in Las Vegas?Of course, Plantinga has beliefs about where the roulette ball will end up. But those beliefs are vague and imprecise , despite Plantinga's startling claim that his perception delivers 'true beliefs' 'the great bulk' of the time.Why does Plantinga claim his God-given memory and perception are reliable, when he uses diaries and glasses?How much of a 'defeater' for the claim of cognitive reliable faculties is a walking admission that what natural selection has served up Plantinga is , in fact, not as reliable as Plantinga wants his faculties to be?I forgot. Only 'a complete fool' would question why somebody writes papers about the reliability of his god-given perception , when the writer of the paper has to wear glasses....But I get used to being insulted rather than answered.
Thanks to Mike for the reference. This is certainly a much longer and more complicated essay than the short piece that Victor referred to. I still find it totally implausible. It feels like someone playing intellectual games to justify their religious belief rather a serious attempt to get at the truth. But it is quite fun to play the game. Raydeon has addressed most of the points, but I want to pick up what he says about probabilities. It is absurd to allocate probabilities to outcomes such as P1 through P4. What kind of probability are we talking about? We are clearly not talking about a frequentist, propensity or classical definition; the only alternative I am aware of is a subjective “degree of belief” definition. But this varies from one individual to another. I have a 100% degree of belief in P4&N&E. So for me the only relevant probability is (P(R/N&E&P4). So then the whole thing turns on (P(R/N&E&P4). Now here it does make sense to talk of a propensity or frequentist definition – assuming you define R in some reasonably acceptable way. We can make an estimate of how often a species would survive if its members were capable of belief and their beliefs were mostly false. But it is not sufficient simply to estimate (P(R/N&E&P4) and declare it to be low. As Radeon points out the thing that evolves is not a particular set of beliefs, but a system for generating beliefs. R is the set of systems for generating beliefs that are mostly (although not entirely) based on believing what is true. We need to compare this set to alternative systems for generating beliefs X1, X2, etc. which generate a vast majority of false beliefs. Call this set X. We are now into a sort of hypothesis testing. The hypothesis H is: R&N&E&P4 and the observed outcome is that the species is viable – call this S for survival.A classical approach would simply estimate P(S/R&N&E&P4) and if it is high enough say we have no grounds for rejecting the hypothesis. I think we can agree that P(S/R&N&E&P4) is pretty high.A Bayesian approach would compare P(S/R&N&E&P4) with P(S/X&N&E&P4) and also take into account the prior probability of R and X. This is vital, anyone can dream up an X system which will work under arbitrary conditions. But we lack any plausible account of how an X system could be created, whereas it is quite easy to see how an R system could come about given the fact that the primitive organisms already show R-like systems.The one thing that does not work is to enumerate all the possible members of X that might work under an arbitrary set of conditions and claim that is a larger set than R. This is not valid statistical reasoning and is effectively what Plantinga is doing.
Steven Carr,Well I'm glad to hear you're used to people insulting you because I'm about to do it again. Plantinga's argument in no way depends on his having full detail on all the breakfasts he has ever eaten. You'd have to wildly misinterpret his argument to come up with that idea.I conclude therefore, that you've wildly misinterpreted his argument.It's strawman after strawman. Come up with a decent objection and I'll attempt to answer it without insulting you.Good luck.Steve
All I can do is quote Plantinga.''It begins from certain doubts about the reliability of our cognitive faculties, where, roughly, a cognitive faculty--memory, perception, reason--is reliable if the great bulk of its deliverances are true.'So why are the great bulk of Plantinga's memories now blank?Plantinga claims he has such a reliable memory that the great bulk of questions you might ask of it return true beliefs.This is very boastful. Perhaps Plantinga has forgotten more philosophy than I will ever know, but if he has forgotten a lot, then his memory is not something which delivers the 'great bulk of the time'So if Plantinga's god-given cognitive faculties like memory and perception are so reliable, why does he need diaries and glasses?Perhaps because Plantinga knows his memory and perception are reliable enough for him to survive on a day to day basis (praise be to evolution), but that these god-given cognitive faculties are not as reliable as he would wish.
Steven Carr,I can't help but think you are being deliberately uncharitable in your reading of me and of Plantinga.He surely admits that we forget things, lots of things. What we don't do all the time is "misremember things", it is not the lack of beliefs which would be problematic is the presence of false beliefs. He uses diaries because he is aware that he forgets certain things. The role is not to correct his beliefs about the past, but to maintain and even recreate them.I'm not saying that there aren't good objections to the EAN, but you can't beat it with every stick that your hand can find. This is a terrible line of objection based on systematic misreadings of his argument.I hope this clears up that objection. When I get some time I might look at some of the better ones posted here. Some of them might even be your own.Steve
Mark Frank has explained things very well.I'll just add that the ID sympathizers I've spoken to fail to understand a certain aspect of evolutionary biology. They all assume that there's one, static environment. This is likely where people like Plantinga are getting the absurd idea that a species can adapt to have false beliefs and be more successful than a species that has a correct belief-producing mechanism.In reality, even if there was only one species of clay-eating bacteria on the planet, there would be thousands of environmental niches. And as populations change and as species migrate, the environment changes and new niches are formed. This means that the rules for survival are continually changing in time and space. Hence, there's a very strong survival advantage to a species that can learn the rules of these new environments within a single lifetime. You cannot fake this ability to adapt to new rules with a collection of false and arbitrary beliefs.Then there's the issue of inference. Do we really think it likely that a mind will possess systematically false beliefs, and statistically infer from the false beliefs the correct survival response? The only way I can see this happening is if the mind systematically infers negated beliefs, and systematically makes inverted inferences from them. And a man who is wrong 100% of the time is the smartest man in the universe.
So Plantinga's memory is reliable because it blanks out totally for 99.9% of the details of his past life, rather than giving him 'false beliefs'?The question remains unanswered.If Plantinga believes his allege god has given him reliable cognitive faculties of memory and perception, why does he wear glasses and keep diaries?'What we don't do all the time is misremember things?'Is this because there are no supernatural beings attacking our memnory and reasoning?
Steven Carr,Carr: "The question remains unanswered".Me: What question exactly?Let me present an abbreviated version of Plantinga's argument. You can then attempt to locate your objection relative to the argument.(1) Naturalism is true [assumed for reductio](2) Evolution is the explanation for the origin of our cognitive faculties [assumed for reductio](3) If (1)&(2) are true, then I have an undercutting defeater for all my beliefs which result from the cognitive faculties explained by evolution(4) Therefore, if (1)&(2) are true, then I have no justified beliefs(5) Therefore (1)&(2) entail widespread scepticism, including scepticism about (1)&(2).(6) Therefore we ought disbelieve (1)&(2).The argument is valid. The interesting questions are about (3), I think. Allow me to formulate a Plantinga-esque argument for (3).(3.1) If I have some belief about the provenance of my cognative faculties which explains the detailed working of those faculties but doesn't make it likely that those faculties should be reliable (that is that the beliefs they produce, if any, should in general be true), then that belief about the provenance of my cognative faculties is an undercutting defeater for any belief which results from the faculties which I believe to have that provenance.(3.2) Evolutionary naturalism in it's explanation of the origin of those faculties doesn't make it likely that those faculties should be reliable.(3.3) Therefore, (3) is true.Now you might object to either (3.1) or (3.2), and I think there are some sensible objections out there which are worthy of discussion. Some people seem to have been making such objections. But which premise or inference is denied in the objection from Plantinga's lack of omniscience and need to wear glasses?If you are entitled to ask what Plantinga's argument is, I think I am certainly entitled to ask you what your objection is.Steve
What is Plantinga's argument?Is Plantinga claiming that ,if our eyes have developed through natural selection, we are not entitled to believe that grass is green, although we can see that grass is green, because we would survive just as well if we believed that grass was blue?I am entitled to believe that grass is green, because I can see that grass is green.If somebody claims that I would get along fine with a belief that grass is blue, then I am simply puzzled as to why that person thinks he is intelligent. Try as I might, I cannot make head or tail of Plantinga's words.Perhaps this is why scientists just ignore him.They are too busy researching our cognitive faculties to worry about such weird arguments as Plantinga's.Please explain why Plantinga can go from 'We are made in the image of God' to 'Therefore our cognitive faculties are reliable', when the guy just doesn't believe his god-given cognitive faculties are as reliable as they should be.
LOVELL(3.2) Evolutionary naturalism in it's explanation of the origin of those faculties doesn't make it likely that those faculties should be reliable.CARRThat is why Plantinga wears glasses.His eyes are not as reliable as they should be.Plantinga is living proof that you cannot refute evolution by claiming it would produce unreliable eyes, because Plantinga demonstrates on a daily basis that eyes are unreliable.What are the chances of someone having perfect eyes?Pretty small.Ah ha! says Plantinga. Evolution predicts that the chances of someone having perfect eyes are pretty small. And we can see that evolution predicts what we find to be true in the world today.Therefore, we cannot believe in evolution.You have to admire Plantinga's chutzpah. If evolutionary theory produces correct predictions, then it is false.There are billions of species that have lived.Only Homo sapiens have developed big brains.Therefore , the chances of a species developing big brains are billions to one.So how do you refute evolution by claiming the chances of developing big brains is small, when that is a successful prediction of evolution?
Mr Carr,If the prediction successful to the degree that Plantinga is suggesting then most of what you believe is false. It would be a mere matter of luck if your belief in Naturalism or evolution is true.Please deny a premise or an inference, and give clear reasons why you deny it. It doesn't matter how hard you try, it will always be impossible to rebut an argument by changing the subject.Steve
PLANTINGA Now according to traditional Christian (and Jewish and Muslim) thought, we human beings have been created in the image of God. This means, among other things, that he created us with the capacity for achieving knowledge ...CARRThis is the sum total of Plantinga's proof that he can trust his perception.If a species is made in the image of God, then it can acquire knowledge.So how does my dog recognise me? How does it know I am its owner?Are dogs made in the image of god?So what is Plantinga's argument?If a species is made in the image of god ,it can acquire knowlege, because it was made in the image of god. If a species is not made in the image of god ,it can still acquire knowlege, because....?Plantinga's arguments are such an embarrassment to Christianity, and its claims that their thinkers are so superior to atheists, that I just love commenting on them.Not only does the Emperor wear New Clothes, but his tailors are rubbish too....
STEVEIf the prediction successful to the degree that Plantinga is suggesting then most of what you believe is false.CARRSo how do you get from 'Most of what I believe is false', to 'I cannot trust any of my beliefs'?Plantinga never bothers with that little step,does he?Why should he?Plantinga himself would laugh at the idea that because he has forgotten 99.9% of the details of his life,then he should not trust his memory of his telephone number.This is too easy....
Let me add to my last comment.Plantinga doesn't reason as per this quote from Carr:"Evolution predicts that the chances of someone having perfect eyes are pretty small. And we can see that evolution predicts what we find to be true in the world today.Therefore, we cannot believe in evolution."In particular the claim "And we can see that evolution predicts what we find to be true in the world today" is no part of Plantinga's argument.He is precisely denying that claim. He thinks one of the things we might be able to forecast from naturalism is the widespread falshood of most of our beliefs. But he denies rather than affirms that widespread falsehood, and invites the naturalist to accept it, and then also the endorse scepticism including scepticism about naturalism (but he's also happy for the naturalist to reject that conclusion, but only if they also reject the naturalistic evolutionary hypothesis which led to that conclusion).Also: Big brains is no guarantee of good brains, at least not in this respect.Steve
Mr Carr,Okay, I'm going to give up for the evening after this one. First, you still haven't denied a premise or an inference. Do you have a problem doing this? If no premise or inference is denied, then the argument and it's conclusion stands.When you say "Plantinga himself would laugh at the idea that because he has forgotten 99.9% of the details of his life,then he should not trust his memory of his telephone number."I agree. But it's irrelevant. As I pointed out earlier today, the point is not the number of beliefs formed it's the truth (or likelihood of truth) of the beliefs which are formed.This is much too easy. ;-)Steve
LOVELLHe thinks one of the things we might be able to forecast from naturalism is the widespread falshood of most of our beliefs.CARRThis is only made false, because you deny that Plantinga's memory should be expected to produce ANY beliefs for 99.9% of the details of Plantinga's life.If Plantinga thinks his god-given eyes produce true beliefs, why does he wear glasses?If his memory is so reliable and produces true beliefs, why does it fail utterly most of the time,to the extent that Plantinga doesn't even attempt to remember what he ate for every meal in his life?Plantinga's argument is that most lottery tickets are losers,so nobody can reasonably believe they have won the lottery.This is a non sequitor.If evolution predicts that it is very unlikely that any given species will develop sophisticated reasoning, then it is not true that it is likely that no species will develop sophisticated reasoning.Of course,Plantinga's world view suffers from these problems in huge measure, as it predicts that supernatural beings will attack Plantinga's perception.
LOVELLAs I pointed out earlier today, the point is not the number of beliefs formed it's the truth (or likelihood of truth) of the beliefs which are formed.CARRThat is a great way to defend the reliability of Plantinga's memory.Simply claim it doesn't work at all almost all of the time,and so never goes wrong.Amazing!
As I pointed out already, sceptics are well aware of the fact that human brains are not perfect and so we might not have the correct theory about evolution.That was discussed and conceded in the latest issue of Skeptical Inquirer.So what is Plantinga's point, other than to spend a lot of words telling sceptics what they know already?It is not irrational to believe in the best theory we have,just as it was not irrational for Newton to believe in absolute space and time.
LOVELLEvolution is the explanation for the origin of our cognitive faculties [assumed for reductio](3) If (1)&(2) are true, then I have an undercutting defeater for all my beliefs which result from the cognitive faculties explained by evolutionCARRI see.So if you have forgotten 99.99% of all the details of your life, then you have a defeater for your belief that the remaining 0.01% has been remembered accurately? Many scientific beliefs were not produced only by cognitive faculties produced by evolution, just as many skyscrapers were not built using only muscle power produced by evolution.Our cognitive faculties are really bad for seeing hundreds of millions of miles away.That is why we built telescopes.Really,Plantinga's arguments have so many holes it is comical, and richly entertaining.
As someone who has debated Carr in years past on other boards, I can honestly say that every minute you spend sincerely attempting to answer his questions is a minute you'll never get back. If I were being even more honest, I'd say that every minute you spend arguing with Carr is a victory for him. Allow me to explain.I used to think Carr was just thick, but now I believe he's a Satanic genius whose method of thwarting the work of Christian apologists, theologians, and philosophers by wasting as much of their time as they will allow him to. Trust me, this way of viewing Carr's responses explains much more than the assumption that he's a reasonably intelligent person of good will. I've seen him around on scores of atheist and theist forums for more than a decade, and judging from his responses, one would think he hasn't learned anything in all that time.I sincerely believe that no one can get that much wrong about every argument he encounters unless he's doing it on purpose.
It seems personal abuse is the only way people can defend Plantinga's claim people can look at green grass and believe it is blue, and that therefore people are not rational to ask for evidence that God made their eyes.Perhaps somebody can explain why naturalism is in doubt, simply because evolution has produce some colour-blind people who cannot see colours correctly.The logic seems to be :- 1) As far as natural selection is concerned, people can survive even if they see wrong colours2) Therefore, naturalists should doubt their belief about colours3) Therefore, sceptics should doubt all their beliefs.What a bizarre argument!And with no conclusion other than that sceptics are right not to believe anything on faith.While Plantinga claims theists are rational in believing God made their eyes, despite no evidence for it, and despite the fact that Plantinga knows his eyes produce false images.
Carr proves that the fool has said in his heart there is no God.
Steven Carr,I don't think I'd go as far as some of the others here and claim that you are an evil genius. I'd just like to point out that you still haven't denied a premise that that you are still confusing a lack of beliefs with the presence of false beliefs. It's a simple distinction and I've pointed it out multiple times now. If your next post is not a denial of a premise or inference (with reference to the numbered premises in my argument) I shall consider this conversation over.Steve
I have already , twice, pointed out that sceptics *agree* with Plantinga, in so much as human beings may have developed brains through evolution that are not capable of formulating the correct theory about evolution.There was an article in the latest issue of Skeptical Inquirer on this very subject.Plantinga's conclusion is that sceptics should be sceptical about their thought processes.Do you think I disagree?
Mr Carr,Thankyou for this response. As per my previous comment, I now consider this conversation over.Steve
Mike,"In any case, a decent, unrebutted objection to the evolutionary argument is not easy to come by. Plantinga has addressed several criticisms"You and I went back and forth on Prosblogian a few weeks back on the EAAN.You presented an "objection" to EAAN. I offered a (several) rebuttal(s).Do you take it that I rebutted it, or have you found a rebuttal to what you presented somehwere else? If so could you paste a link in?
Sorry, I am the persdon who posted as "Paul" on the prosblogian, for a memory jogger.
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