Is Naturalism Still Undefeated?
September 14, 2007 — 23:02

Author: Clayton Littlejohn  Category: Atheism & Agnosticism  Comments: 21

My first post.  It is a bit hand wavy and way, way overdue (Sorry, Matthew).  Again, thanks for the warm welcome earlier.  Now that we've made nice, feel free to explain how I'm missing something terribly obvious.  

I saw that the opening rounds of the Draper/Plantinga debate have been posted over at The Secular Web (HT to JD).  I wanted to look at Plantinga's evolutionary argument against naturalism (EAAN), which can be stated as follows. 

Let R be the proposition that our cognitive faculties are reliable, N the proposition that naturalism is true, and E the proposition that our cognitive faculties have resulted from processes of the sort described by contemporary evolutionary theory.  Plantinga argues as follows:

(1) P(R/N&E) is low or inscrutable.

(2) Informed naturalists (i.e., naturalists who grasp the truth of (1)) cannot rationally believe that R is true.

(C) Informed naturalists cannot rationally hold any beliefs at all, including their belief in naturalism.

To hear Plantinga tell it, the effects of accepting (1) are epistemically catastrophic for the evolutionary naturalist.  There is something about this argument that has troubled me, and I can see that it bothers Draper as well.  Suppose you accept (1) because you think that P(R/N&E) is inscrutable.  What of it?  Does it truly follow that you have a defeater for N&E?

To say 'Yes' suggests that you accept something along these lines.  If we say your evidence consists of EVI, you can be rational in continuing to hold the beliefs contained in EVI only if you can assign a high value to P(R/EVI).  But that seems like a mistake.  Surely as our beliefs 'built up' over time, we accepted beliefs backed by experiences and memories such that we could not assign a high value to P(R/EVI).  The thought that you can rationally accept EVI only if you can assign a high value to P(R/EVI) not only appears to have the untoward sceptical implication that few of us could have acquired the beliefs we would need to justifiably hold to make an informed judgment about the respective merits of, say, theism and evolutionary naturalism, it seems awfully close to committing a kind of levels-confusion.  If you think that the truth of R is a necessary condition on having justified beliefs produced by the faculties that are mentioned in R and combined that with the view that you'd have a defeater for any set of beliefs on which you could not rationally assign a high value to P(R/those beliefs), it seems for those beliefs to be justified, you'd have to be in a position to justifiably believe that the conditions for justification obtained for such beliefs.  If, however, you think that this further requirement is not necessary for justification, why would it matter that you could not assign a high value to P(R/those beliefs)?

Regardless of whether you agree with Draper (and myself) that there is something fishy going on here with the inference from (1) to (2), Plantinga has made a move that I find rather surprising.  I haven't followed the development of his EEAN as closely as some, but the new version of the argument he's offering replaces (1) with:

(1') P(R/N&E) is low.   

Problem solved.  If Plantinga can justify (1') maybe evolutionary naturalists are really in hot water.  

Draper doubts (as do I), that it is unlikely that R is true given that our ancestors were not weeded out by evolutionary forces.  Fitness does not guarantee reliability, but on its face, the possibility that creatures of the kind we take ourselves to be (slow, soft, delicious to predators, not equipped with poisonous spines, etc…) could have survived without relying on our wits seems rather remote.  To defend (1'), Plantinga seems to concede something to Draper.  He concedes that it is unlikely that our ancestors would not have been weeded out were it not the case that their behavior was fit _and_ they had something that indicated something about those aspects of the environment that needed to be indicated for our ancestors to navigate it successfully.  What he suggests is that granting this much does not give us any right to say that the likelihood that such creatures would be equipped with reliable belief-forming mechanisms is high. 

Perhaps I'm being naive, but it seems to me that the odds that our ancestors could have flourished and brought us here if they lacked reliable belief forming mechanisms seems low.  Prima facie, it would seem to be nothing short of a miracle if Ug and his wife Ug could have lived past infancy, bred, and ensured that their children, Ug, Ug, and Ug, would live past infancy without reliable ways of determining the presence of predators, the location of food, ways of growing food, ways of staying warm, how to deliver babies, etc… To this, Plantinga's response seems to be somewhat concessive.  He seems to grant to Draper that the long term survival of our species is reason to expect that their cognitive faculties were reliable.  However, he thinks that this shows only that given that our ancestors' behavior was fit, it is likely that they had some reliable way of indicating how things were outside of them and how to satisfy their desires, but (and this seems key) it does not follow that it is likely that we had reliable ways of representing how things were in terms of our beliefs.  

In a broad sense, a belief-less entity might have a reliable way of indicating the presence of food.  Here, think of frogs and their behavior which requires a reliable fly detector.  We don't have to assume that the frogs have beliefs about flies to explain their success.  So, if we grant that some reliable action-guiding indicators suffice for explaining the success of behavior, it does not follow that having reliable belief-producing mechanisms is likely.  

We can distinguish between the critters whose behavior is fit and fit (in part) because of indicators that guide behavior without producing belief (and, hence, without producing true belief reliably), but what I don't get is why such a possibility gives us reason to say that it is _unlikely_ that creatures that have such beliefs and such cognitive indicators guiding action have their beliefs reliably turn out to be true.  I don't understand why the possibility of such creatures gives us reason to think that creatures that engage in the kind of complex behavior that we do and our ancestors did would have likely succeeded without reliable belief producing mechanisms.  As he's granted that the onus is on him to show that the likelihood of R is _low_ granting what he's granted about successful behavior and the need for reliable indicators as to how the external environment is, I just don't see how he thinks he has carried out this task.  I can see saying that the likelihood of R on the assumption that our ancestors' behavior was fit and more complicated than the simple creatures he discusses that get by on external world indicators might be inscrutable, but we're no longer to assume that this is a cause for concern.  A belief's defeat is now taken to hang on a demonstration that it is unlikely to have been produced by reliable belief producing mechanisms.

A little help?  Has Plantinga conceded too much to Draper?

Comments:
  • DRM

    I think the most reasonable response to this I can think of right now is: Huh?
    I’m a bit surprised nobody has responded. Guys, this is the token atheist!

    September 15, 2007 — 3:20
  • Hi Clayton, you write,
    “Perhaps I’m being naive, but it seems to me that the odds that our ancestors could have flourished and brought us here if they lacked reliable belief forming mechanisms seems low. Prima facie, it would seem to be nothing short of a miracle if Ug and his wife Ug could have lived past infancy, bred, and ensured that their children, Ug, Ug, and Ug, would live past infancy without reliable ways of determining the presence of predators, the location of food, ways of growing food, ways of staying warm, how to deliver babies, etc… ”
    This confuses practice and belief. What matters to survival is acting the right way, not believing the right way: running away when you see a sabor tooth tiger, for instance. It does not matter that you have correct beliefs (or belief forming mechanisms) in the process leading to that action. Somewhere Plantinga uses (something like) the example of believing that tigers are friendly and also believing that the best way to reciprocate friendliness is to run away. These beliefs are widly mistaken, of course, but they produce survival behavior (i.e. running away from tigers). But the examples you offer are much better, and cut in favor of Plantinga’s view. Surely you don’t need any background in agricultural science to get food to grow. It is enough to have some set of false beliefs about why plants grow (the trolls causes the seeds to grow) and what governs weather changes (the gnomes do it) to get the right result. You don’t even need to know the correct location of predators. If you believe that a predator is behind you when time he is in front of you, that predators are friendly, and that the best way to greet a predator that is behind you is to shoot an arrow in front of you, you will likely survive. Having the right beliefs is not what ultimately matters. It is having beliefs (and desires, etc.) that generate survival behavior.
    So I guess the line you need to take is that your chance of survival increases if your survival behavior is the result of true beliefs (rather than useful beliefs).

    September 15, 2007 — 8:58
  • DRM,
    For the record, I’ve been told I’m not the token atheist. Anyway, I’m not surprised there hadn’t been any responses prior to yours–I hadn’t actually posted until reasonably late last night.
    Mike,
    I’m not sure I’ve confused practice and belief, exactly. Rather what I’m saying is this. I don’t see in these examples reasons to think we ought to assign a _low_ value to R given E, N, and that the behavior of our ancestors was fit, because given Plantinga’s revised defeater principle, it seems to show E&N is self-defeating, we need reasons to assign P(R/E&N) a low value.
    It is true that, in a broad sense, we can imagine people whose wildly false beliefs let them navigate their environments. But I don’t see how this adds up to an argument for the proposition that:
    (i) Given our evidence, P(R/E&N) is small.
    Rather than:
    (ii) Given our evidence, we cannot assign a value to P(R/E&N) that is high.
    So, if I was feeling brave and wished to argue that (i) was false, I might try to show that your chance of survival increases by having true beliefs rather than false ones. But, if I’m feeling more timid, it seems sufficient to block the latest version of Plantinga’s argument if we note that he’s not warranted in asserting (ii).

    September 15, 2007 — 10:27
  • Maybe an analogy will help.
    [I think this is partially inspired by something Sober said.]
    Suppose we ask whether we should say that P(R/Theism) is high, low, or say that it is inscrutable. According to the original defeater principle, if P(R/T) is low or inscrutable, belief in theism is self-defeating. Now, someone might say that P(R/T) is neither low nor inscrutable. The value is high, they might say, because we were created in God’s image.
    But, suppose we discover that we are unreliable in a number of areas. Someone might say that as we’d expect not to be unreliable in these areas if theism were true, we’ve found empirical evidence against theism. Against this, someone might say that God moves in mysterious ways, has inscrutable intentions, etc… It would appear that if this is the whole of the response, they’d have to concede that P(R/T) is low or inscrutable.
    Now, on the old defeater principle, that’s bad news. On the new defeater principle, that’s ‘irrelevant’ news (to borrow a phrase from The Office). Personally, I think if someone concedes that P(R/T) is inscrutable, I think it’s not a big deal. All I’m suggesting is that I don’t see that the evolutionary naturalist is in a different camp. I see no reason for confidence in R, but no reason for confidence that R is not likely.

    September 15, 2007 — 10:40
  • I was talking about this passage, part of which I quoted above,
    Perhaps I’m being naive, but it seems to me that the odds that our ancestors could have flourished and brought us here if they lacked reliable belief forming mechanisms seems low
    Still, I should have been more careful. Here, it seems like you’re confusing the role of belief and the role of practice in survival. I say this because you seem to be claiming that our survival requires a true-belief forming mechanism (or a truth tropic mechanism). My point was simple. Our survival does not require that. Our survival requires not true belief but useful belief. That is, selection pressure makes valuable the possesion of useful beliefs (i.e., beliefs that help me to act in the right ways to survive). So we still need an argument that what is selected for are only those useful beliefs that are true. Where’s that argument? As it is, the set of true+useful beliefs is much smaller than the set of useful beliefs. If we all know (and as far as I can see, this is all we have been given so far) is that the set of beliefs selected for is useful, and the set of useful beliefs far outstrips the set of true+useful beliefs, then it seems perfectly reasonable to conclude that Pr(R/E&N) is low. I see how that conclusion might be unwelcome; but absent some other argument for the greater evolutionary value of true+useful beliefs over useful beliefs, it doesn’t seem like an unreasonable conclusion.

    September 15, 2007 — 12:10
  • Steven Carr

    What does Plantinga mean by ‘reliable cognitive faculties’?
    Suppose I see a 300 pound tiger coming towards me.
    I think ‘That tiger must weigh at least 305 pounds.’
    That is a false belief.
    Suppose I think ‘That tiger must weight at least 5 pounds’.
    That is a true belief.
    In which case are my faculties more reliable?
    ‘Perhaps I’m being naive, but it seems to me that the odds that our ancestors could have flourished and brought us here if they lacked reliable belief forming mechanisms seems low’
    I think you are being naive.
    What reliable belief forming mechanisms did ancestral cockroaches have?
    And how come cockroaches have survived for so long, without reliable cognitive faculties?

    September 15, 2007 — 13:29
  • Steven Carr

    One thing I don’t understand about Plantinga is the fact that supernaturalism posits the possible existence of demons who can attack our reasoning and senses.
    How then can Plantinga avoid being hoist with his own petard?
    And why would theism posit that God would want to grant Homo sapiens the gift of reliable cognitive faculties , rather than Tyrannosaurus rex or Rattus rattus?
    What marked us out as such a special species, if Plantinga teaches that evolution would not otherwise have given us the qualities that would have marked us out as such a special species?
    It is a bit like a lottery.
    Lottery wins would easily grant that the chance of their winning the lottery had been absolutely remote.
    Is that an argument against their having won the lottery?
    Just as the one species out of thousands of millions which developed the brains we have would grant that the chances of natural selection developing out brains are thousands of millions to one against.
    Plantinga’s alternative viewpoint is that the lottery organisers must have wanted that particular lottery winner to win, as the chances of that winner winning were hugely against.
    Just as Plantinga argues that God must have wanted Homo sapiens to win the lottery of getting ‘reliable cognitive faculties’, as the chances were hugely against natural selection selecting Homo sapiens.
    The thesis that lottery organisers want Mr A to win one week, Mr B to win the next and Mrs C to win the third is a very simple thesis which explains all the facts.
    Contrasting that with the huge odds that the lottery would just happen to select by chance Mr A to win, and then Mr B and then Mr C, the explanatory power of guided lotteries is easily seen to be preferable to the hugely improbable happenstance that believers of non-guided lotteries must believe in.
    But there is a huge flaw in that argument.
    So there must be a huge flaw in Plantinga’s argument.

    September 15, 2007 — 13:45
  • Steven Carr

    MIKE
    So we still need an argument that what is selected for are only those useful beliefs that are true.
    CARR
    Why?
    The belief that there are no supernatural entities was not formed under life and death conditions, no more than the belief that there are no unicorns was.
    Naturalists do not believe that natural selection produced a lack of belief in genies, ghosts, witches, vampires, gods, angels or demons.
    So I never really understood Plantinga’s argument.

    September 15, 2007 — 13:56
  • Steven,
    By ‘naive’, I take it you mean I ‘naively overlooked the fact that our ancestors included ancestral cockroaches’? 🙂
    Anyway, I’m not sure why you think cockroaches lack reliable cognitive faculties. Tried stepping on one lately?
    Mike,
    I think I get the point you’re making, but what seems to me to the natural follow up response is this.
    True, let’s say, evolution selected for useful beliefs where that is taken as beliefs that were useful for the particular believers in question where that takes into account, say, the needs, vulnerabilities, skills, and behaviors of the believers in question. To be sure, there are some imaginable and perhaps actual critters for whom it is unlikely that given their niche, their needs, their skills, their vulnerabilities, and their behaviors that they have reliably true beliefs guiding their behaviors. This would particularly be true for simple behaviors that did involve intrapersonal co-ordination across time and inter-personal co-ordination as well. But, an advocate of E&N should question the move from this to the move to us. For it seems that the likelihood of R for some imagined critters will vary depending upon things like the kinds of behaviors they ‘gambled on’ in order to withstand selection pressure.
    When we look at the behaviors our ancestors gambled on to withstand evolutionary pressure (descriptions of which I take it are included in E), whose characteristics partially explain the kinds of beliefs and desires we now have, could have successfully carried out those behaviors that they engaged in without being selected out were it not for reliable belief forming mechanisms? Here, it seems we need to take account of the things like the likelihood of having developed language, tools, formed social groups that involved interpersonal co-operation, etc… and not having had reliably true beliefs involved in the process. In the abstract, of course the class of possible sets of true beliefs is larger than the class of possible true & useful beliefs. However, comparing the class of:
    (a) consistent but mostly false sets of beliefs that would have enabled our ancestors to carry out the behaviors that they did carry out to withstand selection pressure;
    (b) consistent but mostly true sets of beliefs that would have enabled our ancestors to carry out the behaviors that they did to withstand selection pressure.
    I’m not sure (a) is much larger than (b). For among the things that winnows down (a) is not just that the beliefs in question have to fit with the behaviors an advocate of E&N might suppose our ancestors in fact relied on to survive but also that we can lower the probability that some false, consistent set of beliefs by adding evidence that suggests that there is no plausible story about how such beliefs would be made available to those ancestors.

    September 15, 2007 — 14:09
  • Clayton, you write,
    When we look at the behaviors our ancestors gambled on to withstand evolutionary pressure. . .whose characteristics partially explain the kinds of beliefs and desires we now have, could [they] have successfully carried out those behaviors that they engaged in without being selected out were it not for reliable belief forming mechanisms? Here, it seems we need to take account of the things like the likelihood of having developed language, tools, formed social groups that involved interpersonal co-operation, etc… and not having had reliably true beliefs involved in the process.
    I’m not sure I follow all you say here. But I think part of the point you’re making is that we needed to engage in certain sorts of social behaviors in order to survive (given the kinds of beings we are) and those behaviors depend on our being cognitively reliable. I just don’t see why. There is incredibly complex social interaction in ant colonies, and certainly that behavior was selected for. But there is obviously no need for reliable belief formation to make it happen. Similarly for us. What can be confusing here is that, as a matter of fact, I think we are cognitively reliable and I think we did rely on this to withstand selection pressure. There is still selection pressure, especially at 5pm on any highway in the city. What I’m questioning is whether the reliability can be accounted for by N&E. It’s not obvious that it can.

    September 15, 2007 — 14:39
  • Steven Carr

    ‘Anyway, I’m not sure why you think cockroaches lack reliable cognitive faculties. ‘
    CARR
    As Plantinga claims they could not develop through natural selection, did God grant cockroaches reliable cognitive faculties?
    I can’t find in the debate where Plantinga even gives a working definition of ‘reliable cognitive faculties’.
    So I am at a loss as to how to evaluate how likely they are to develop through natural selection.
    Could Plantinga not short-circuit the debate by pointing out that the belief that skyscrapers will not fall down if well designed could not have developed through natural selection?
    As there are only 2 alternatives to how species X developed belief Y (God or natural selection), then the debate would be settled.

    September 15, 2007 — 14:49
  • Christian Lee

    Hi Clayton,
    I think my response is this. The Prob (R/B) where ‘B’ is our background evidence is very high. We know our belief (okay, “I” know my) belief forming mechanisms are reliable given my background knowledge. So, (R/N & E & B) is high, even if (R/E & B) is low. That’s to say that our reliable belief forming mechanisms confirm the existence of a non-evolutionarily directed process by which we form beliefs.
    That doesn’t get on God, or Monotheism, or Christianity at all. And once we consider other arguments, like the argument from evil, the probability that God exists is quite low. So, I’m inclined to concede Plantinga’s argument and respond by saying that it doesn’t show much, and that it certainly doesn’t give one a defeater for naturalism when the background beliefs are considered.

    September 15, 2007 — 17:04
  • Drm970

    For the record, I’ve been told I’m not the token atheist. Anyway, I’m not surprised there hadn’t been any responses prior to yours–I hadn’t actually posted until reasonably late last night.
    Ah. I see now. As I was reading your post last night, it was second on the post list, and the date the page said you posted was the 9th. That’s an awful long time for an interesting post to be up on this board with no responses, but, I was misled by the software! I guess the environment was not congenial to my epistemic faculties!
    Steven: Plantinga defines reliability in all three of his Warrant series, as I remember. Unfortunately, I loaned WPF and WCD to a friend over 2 years ago, and have received the run around on getting them back ever since. So, provided you have a copy of Warranted Christian Belief, which I’ve seen you quote from elsewhere, turn to page 222 and read on.

    September 15, 2007 — 20:29
  • Christian,
    I think it’s an interesting suggestion, but I’ll have to think more about it.
    Mike,
    One thought. The ants have mechanisms that explain their success at social activity, but those mechanisms are not mechanisms our science suggests that we or our ancestors had. So, if we study ourselves and notice that we manage to engage in social co-operative behavior without this non-belief involving mechanisms, perhaps such behavior is more likely successful if R is true than not.
    Anyway, consider a related response. I mentioned a number of behaviors that someone might (or might not) think would more likely be successful given R than not. Here’s another behavior. We came from ancestors that apparently give rise to creatures that use language for the purposes of scientific theory construction and those theories have been both massively confirmed and have helped us survive. What are the odds that such behavior would be exhibited by creatures who lacked reliable belief forming mechanisms? Slim, you might think.
    Now, maybe behaviors such as these are out of bounds. If they’re in bounds, though, maybe it helps the cause. Now, you might think that such behaviors are out of bounds because we have some reason to think it is unlikely that we would exhibit such behaviors given E&N. Perhaps, but then I can imagine a naturalist responding as follows (this is partially inspired by something Christian said and something I think Sober noted).
    Suppose that I’m not just a reflective naturalist, but also a non-evidentially challenged naturalist. I have (or take myself to have) good grounds for naturalism. I encounter P’s argument which, if it works, suggests that P(R/E&N) is low. What am I to do? Well, I might start thinking about E. After all, why not say that E is a working hypothesis and revise E? I’ll wait for some replacement theory to tell the story about how we came to be and how our ancestors could have come to be the kinds of things that give rise to such wonderfully gifted theory-constructing critters. That won’t be a theistic story, says the naturalist, what with their antecedently having grounds for naturalism.

    September 15, 2007 — 20:31
  • Drm970

    What does Plantinga mean by ‘reliable cognitive faculties’?
    Suppose I see a 300 pound tiger coming towards me.
    I think ‘That tiger must weigh at least 305 pounds.’
    That is a false belief.
    Suppose I think ‘That tiger must weight at least 5 pounds’.
    That is a true belief.
    In which case are my faculties more reliable?

    You played into Plantinga’s hands with that one, Steven. The answer is that in the case of you believing the tiger must weigh at least 5 pounds, your faculties are more reliable for producing true beliefs, since 305 is false. That’s fairly simple to see.
    That doesn’t get on God, or Monotheism, or Christianity at all. And once we consider other arguments, like the argument from evil, the probability that God exists is quite low. So, I’m inclined to concede Plantinga’s argument and respond by saying that it doesn’t show much, and that it certainly doesn’t give one a defeater for naturalism when the background beliefs are considered.
    I don’t believe this works as a response to EAAN. For similar reasons, I don’t believe Clayton’s most recent post works:
    Suppose that I’m not just a reflective naturalist, but also a non-evidentially challenged naturalist. I have (or take myself to have) good grounds for naturalism. I encounter P’s argument which, if it works, suggests that P(R/E&N) is low. What am I to do? Well, I might start thinking about E. After all, why not say that E is a working hypothesis and revise E? I’ll wait for some replacement theory to tell the story about how we came to be and how our ancestors could have come to be the kinds of things that give rise to such wonderfully gifted theory-constructing critters. That won’t be a theistic story, says the naturalist, what with their antecedently having grounds for naturalism.

    Since on Plantinga’s objection, your background beliefs are affected by the same defeater.
    Similarly, it doesn’t seem to me that your “antecedent grounds” for naturalism are antecedent in the relevant sense. You may have good grounds, prior to learning of the argument. But, if the argument is successful, it is epistemically antecedent to your grounds, thus providing a defeater for your grounds as well.
    Those are my thoughts on the matter.

    September 15, 2007 — 22:51
  • Drm970

    Oop! I failed to consider a little piece of Clayton’s argument.
    I think it’s perfectly legitimate for the naturalist to abandon evolution as the explanation for the production of his faculties. I think Thomas Nagel does this, or at least he seems to. He says somewhere, I recall that if we were to find that our faculties were generated via evolution, we would have good reason to doubt them. As I said, I think it’s perfectly legitimate, but an alternate explanation doesn’t seem to be forthcoming.
    I also forgot to reply to Steven on one point. Theism offers no reason to think demonic influence is a universal affliction. So the probability that some peoples faculties will be unreliable is high, but the probability that any one person’s faculties will be unreliable is low.

    September 15, 2007 — 23:00
  • Blake

    Isn’t the real question how the mechanistic explanation of survival of the fittest can give us any confidence that we would have reliable cognitive faculties for things like math, theoretic matters like quantum mechanics and relativity theory and matters that don’t touch upon our survival in the least? It is also a total mystery how and why such a mechanism would develop something so totally beyond any usefulness like a massive parallel processing system that we find in our brain/neural systems. How Ug and Ug survive without such cognitive capacities isn’t much of a mystery because we could be fit for fight or flight without the ability to think. It simply seems that we have no reason to believe that we have reliable cognitive faculties for theoretic matters. Yet the naturalistic position assumes that it can be arrived at by precisely the kind of theoretic reasoning we have good reason to believe naturalistic evolution would not develop. Thus, it seems to be a self-defeating position. As I understand it, that is the argument and it seems persuasive to me in this sense.

    September 16, 2007 — 1:36
  • Steven Carr

    Really? So Plantinga equates ‘reliable cognitive faculties’ with seeing a 300 pound tiger and thinking ‘That tiger must weigh at least five pounds’?
    Simply because that is a true, but almost irrelevant belief?
    While a belief that the 300 pound tiger must weight at least 305 pounds is an indication that you are not thinking straight, because that is a false belief?
    Amazing!
    Clearly the second belief is far more reliable, because it is the one that is the best belief to act upon.
    But as Plantinga never defines ‘reliable cognitive faculties’ in the debate, it is rather pointless discussing them.
    Clearly he can’t have refuted naturalism if he never says what it actually is that naturalism cannot produce.
    Let me have a try at defining ‘reliable cognitive faculties’ for Plantinga.
    Are our cognitive faculties reliable if they produce logically invalid conclusions?
    For example, is this conclusion – I must run away from the tiger to maximise my chances of staying alive – a logically valid deduction from this premise – There is a tiger about to attack me.
    Obviously not, as Plantinga has written whole books explaining how to create possible worlds where conclusion B does not logically follow from premise A.
    See his defense against the argument from evil for one example.
    It was that method of reasoning that made Plantinga world-famous.
    So , according to the methods of Plantinga, this ‘I must run away from the tiger to maximise my chances of staying alive’ is not a valid logical deduction from that – ‘ There is a tiger about to attack me.’
    So how can our cognitive faculties be reliable if we can use Plantinga’s methods to demonstrate that these cognitive faculties make INVALID logical deductions?
    Does God ensure that our cognitive faculties make invalid logical deductions?
    Surely a true God would ensure that our cognitive faculties made *valid* logical deductions.

    September 16, 2007 — 4:41
  • Steven Carr

    ‘Theism offers no reason to think demonic influence is a universal affliction. ‘
    Well, that is what the demons want you to think.
    I think I will just ignore all Plantinga’s arguments until he demonstrates he is not posssessed by demons.

    September 16, 2007 — 4:47
  • A couple of thoughts.
    1. I think Clayton’s objection to the original argument slides between a probability whose value we do not presently and a probability that is inscrutable. Plantinga can respond: “Yes, of course, sometimes we get evidence E such that we don’t know whether P(R|E) is high. That’s fine. It may mean would should do some investigating and try to figure it out, of course. But it is different if we can actually come up with a positive argument that P(R|E) is inscrutable. At that point, we do have a problem on our hands.” (It might help here to distinguish between inscrutable and undefined probabilities. I don’t know what that does to te argument.)
    2. Maybe what would help advance the discussion here would be to start by thinking about what theories of mind the argument works really well on. It seems to me that the argument works best against a naturalist property dualist who thinks that mental states are epiphenomenal. On such a view, zombies would do just as well evolutionarily as persons, and beings with wildly wrong beliefs could presumably do just as well as zombies, since beliefs make no causal difference there.
    On the other extreme, the argument works poorly against views with a significant behavioristic or externalist component.
    First approximation: To think that a tiger is dangerous just is to try to run away from a tiger. If so, then of course beings to which tigers are dangerous are going to have the belief that tigers are dangerous. OK, we know this view has problems–one might be running away for some perverse reason, as Plantinga says.
    But we can perhaps complicate the view as follows. Absent further beliefs, the tendency to run away from tigers constitutes a belief that tigers are dangerous. The presence of further beliefs can change that, however. In the presence of a belief that running away is the best way to catch prey, the tendency to run away from tigers partially constitutes the belief that tigers are prey.
    On this kind of account, it may well turn out that when the same fit behavior can be produced by a set S of true believings and a set S* of false believings, the set S is simpler, and thus more likely to evolve. For instance, in the above example, the set S that produces the running away from tigers by means of a true belief contains only one item, the tendency to run away from tigers. On the other hand, S* must contain a bunch more stuff, such as a belief that tigers are nice and that one should run away from nice things.
    Probably, Plantinga’s argument is also going to fail against an anti-sceptical content-externalist according to whom the beliefs of someone raised as a brain in a vat connected to a computer simulation of our world are not about tables and chairs (even if they are constituted by the same neural states as our belies about tables and chairs) but about the states of the computer chips making up the simulation. I am not a philosopher of mind, so I don’t know who holds this view, but it seems to me to be one that I’d find plausible were I a naturalist.
    3. As a way of making a part of Plantinga’s argument plausible, consider a creature kind of like us but whose desires are wired to behavior in reverse. Thus, the creature tends to pursue something iff it does not desire it. Suppose, further, that this creature’s beliefs are the negations of typical human beliefs under the circumstances. For instance, when faced with a tiger, the creature tends to form the belief that there is no tiger there. Suppose the creature has inference rules that are the reverse of ours. Thus, whereas we infer from the presence of a tiger that there is a predator there, this creature infers from the absence of a tiger that a predator is absent. The creature believes, let us suppose, that in the absence of a predator, running away is not beneficial (ceteris paribus). Consequently, in the presence of a tiger, the creature forms the belief that there is no tiger, and hence no predator there, and hence that it is not beneficial to run away. From this, it forms–and this connection we leave as in humans because the connection between belief and desire may be analytic–the lack of a desire to run away. And so it tends to run away, since it tends to do what it does not desire. (This thought experiment is based on Jerry Massey’s work on intranslatibility.)
    Such a creature, if it is possible, would do precisely as well as humans do. Moreover, it is not at all clear that such a creature would need to be significantly more complex than we are. The rules of inference the creature uses are just as simple as our rules of inference. It may be that beliefs about the presence of something are simpler than beliefs about the absence of something, but that is not clear.
    If this creature is as likely to evolve as reliable creatures are, then P(R|naturalism and evolution) cannot exceed 1/2. And since there surely are other hypotheses that will yield fit but epistemically unreliable creatures, P(R|naturalism and evolution) is less than 1/2.
    However, this argument only works if we’re not too much of a behaviorist or externalist. If in the absence of other beliefs, what it is to believe that there is a dangerous animal there is to run away, or if what makes a belief about a tiger is its (the belief’s) being caused by the tiger in the right way, this argument probably won’t work.

    September 16, 2007 — 13:23
  • Drm970

    Clearly the second belief is far more reliable, because it is the one that is the best belief to act upon.
    In one sense you’re clearly right. The second belief(at least 305 pounds) is far more reliable to act upon for survival. However, the belief is, obviously, false. Had you read the reference I gave you, you would know how Plantinga defines reliability. It seems you play into his hands again. Plantinga never disputes that evolution produces faculties which are reliable in the pursuit of survival. In fact, he counts on it, as it is a necessary part of his argument. Here’s a hint: Reliability has to do with truth.
    Well, that is what the demons want you to think.
    That’s pretty funny. I had a good laugh at that.

    September 16, 2007 — 16:44