by leavingwt 20 Replies latest jw friends
According to Plantinga, blind evolution doesn't care about "truth." It only cares about adaptive survival.
These are not the same thing.
If, our cognitive faculties are purely the product of naturalism, can they be trusted to be able to arrive at truth?
I posted an essay on the subject above.
So far as adaptiveness of their behavior goes, it doesn't matter whether those beliefs are true or false.
BTS
For many years I was a naturalist – in belief if not in name. Naturalism is like the evolved cousin of materialism. Materialism states that all there is in the world is matter, and everything is utterly and exhaustively explainable in terms of matter. There are severe logical issues with this belief, and most former-materialists jettisoned this belief in favor of a slightly more tenable and vague notion of “naturalism”.
Naturalism still accounts for all things in terms of the whole universe (i.e. all of nature), but she allows for things like “energy” which is not strictly material. However, if naturalism is true, then ultimately all things that occur are ultimately entirely reducible to the workings of the system.
This would seem to be problematic for some beliefs, like that of freewill. It set’s up an utterly entirely deterministic universe whereby all things that occur had to occur. That, though demonstrative of our point, is not in and of itself our point.
The point is that if everything is utterly explainable by the system simply “working itself out” in whatever fashion it happens to, then all of my beliefs are utterly irrational; they are caused and not arrived at by any actual act of reason.
I'd like to underscore:
if naturalism is true, then ultimately all things that occur are ultimately entirely reducible to the workings of the system.
The point is that if everything is utterly explainable by the system simply “working itself out” in whatever fashion it happens to, then all of my beliefs are utterly irrational; they are caused and not arrived at by any actual act of reason.
Here is one thoughtful response to Plantinga (PDF)
http://philosophy.wisc.edu/sober/fitelsoon%20and%20sober%20on%20plantinga.pdf
Here is an excerpt from their conclusion:
“.. .if evolutionary theory does say that our ability to theorize about the world is apt to be rather unreliable, how are evolutionists to apply this point to their own theoretical beliefs, including their belief in evolution? One lesson that should be extracted is a certain humility— an admission of fallibility. This will not be news to evolutionists who have absorbed the fact that science in general is a fallible enterprise. Evolutionary theory just provides an important part of the explanation of why our reasoning about theoretical matters is fallible.
Far from showing that evolutionary theory is self-defeating, this consideration should lead those who believe the theory to admit that the best they can do in theorizing is to do the best they can. We are stuck with the cognitive equipment that we have. We should try to be as scrupulous and circumspect about how we use this equipment as we can. When we claim that evolutionary theory is a very well confirmed theory, we are judging this theory by using the fallible cognitive resources we have at our disposal. We can do no other.
Plantinga suggests that evolutionary naturalism is self-defeating, but that traditional theism is not. However, what is true is that neither position has an answer to hyperbolic doubt. Evolutionists have no way to justify the theory they believe other than by critically assessing the evidence that has been amassed and employing rules of inference that seem on reflection to be sound. If someone challenges all the observations and rules of inference that are used in science and in everyday life, demanding that they be justified from the ground up, the challenge cannot be met. A similar problem arises for theists who think that their confidence in the reliability of their own reasoning powers is shored up by the fact that the human mind was designed by a God who is no deceiver. The theist, like the evolutionary naturalist, is unable to construct a non-questionbegging argument that refutes global skepticism.
This would seem to be problematic for some beliefs, like that of freewill. It set’s up an utterly entirely deterministic universe whereby all things that occur had to occur. That, though demonstrative of our point, is not in and of itself our point.
The point is that if everything is utterly explainable by the system simply “working itself out” in whatever fashion it happens to, then all of my beliefs are utterly irrational; they are caused and not arrived at by any actual act of reason.
I think you'll find that many non-believers reject the notion of freewill.
The portion I've highlighted in red above seems to be far too black and white, IMHO. I'm just guessing, obviously, but it would seem more accurate to say "limited" reason, given the the specifics at hand, etc.
This is all very interesting. Thank you for those links/articles.
Here is an excerpt from their conclusion:
There is methodological naturalism, and metaphysical naturalism.
As a working scientist, you can do the former. In fact, you must, as a basic assumption underlying your work.
This does not however, mean that the latter is necessarily true.
BTS
Re. BTS's article on Platinga.
I will easily give Platinga that since we have evolved, our brain is selected for survival primarily and not for being perfect inferrence machines, and that it can be expected to act faulty in many ways. Thats completely trivial. Since i had heard his name a few times i thought there was some smart argument that connected this to atheism. Turns out there is a very faulty argument:
So consider any particular belief on the part of one of those creatures: what is the probability that it is true? Well, what we know is that the belief in question was produced by adaptive neurophysiology, neurophysiology that produces adaptive behavior. But as we've seen, that gives us no reason to think the belief true (and none to think it false). We must suppose, therefore, that the belief in question is about as likely to be false as to be true; the probability of any particular belief's being true is in the neighborhood of 1/2. But then it is massively unlikely that the cognitive faculties of these creatures produce the preponderance of true beliefs over false required by reliability. If I have 1,000 independent beliefs, for example, and the probability of any particular belief's being true is 1/2, then the probability that 3/4 or more of these beliefs are true (certainly a modest enough requirement for reliability) will be less than 10(to the power -58). And even if I am running a modest epistemic establishment of only 100 beliefs, the probability that 3/4 of them are true, given that the probability of any one's being true is 1/2, is very low, something like .000001.[7] So the chances that these creatures' true beliefs substantially outnumber their false beliefs (even in a particular area) are small. The conclusion to be drawn is that it is exceedingly unlikely that their cognitive faculties are reliable.
STOP STOP my eyes are bleeding! Platinga want to argue two things: Every particular belief has a 50/50 chance of being true or false. Then he introduce the idea that our creatures have eg. 1000 independent beliefs, and he repeat a Hoyles-fallacy argument and conclude that every epistomology of eg. 1000 beliefs are true is very, very low.
Notice the change of wording. The word "independent" is required because otherwise his calculation (indeed, his entire argument) fall apart, but elsewhere in the article the word independent is missing. It is a lot easier to give an example. Suppose my set of beliefs has to do with math. So i have a set of "particular beliefs", namely the following 7:
But i would dare anyone to claim these statements are independent, they are all either true or false. As far as platingas assignment of probabilities, suppose we take his hypothetical alien species from the article as an example, and lets just look at 1+1 = 2. As far as I can tell, platinga want to argue that is true with probability 1/2. Now lets just assume the alien species think that 1+1 = 8. Is that also true with probability 1/2? Is it also true with probability 1/2 that 1+1 = 2017?. Clearly there is a difficulty here, and it all boil down to (1) what is a (set off independent) belief(s) and (2) how do we assign probabilities to such a set with the above example in mind.
Furthermore, a good question: Do platinga really want to argue that any given alien species believe with probability 1/2 that 1+1 is NOT 2? That seem to be the most stupid thing i have heard all week, but it still seems like what he write.
His argument is true as far as i can tell only for sets of statements such as
But these are hardly things which fall outside the framework of naturalism and hardly has an impact on anything; if someone want to critisize my choice of statements, and argue there is a more important set of beliefs his argument above hold for, that might be true but its not my argument and i would love to see them.
Platinga then continue
If there isn't a defeater for that defeater—a defeater-defeater, we could say—she can't rationally believe that her cognitive faculties are reliable. No doubt she can't help believing that they are; no doubt she will in fact continue to believe it; but that belief will be irrational.
New concept: cognitive faculties. I suppose that have to do with how we reason about the world, and not our set of beliefs -- that the 50/50 argument does not apply to this as it is formulated (and if he reformulated it, it would ofcourse still be as invalid as before) should come as no surprice, but at any rate it is easy to blow the hypothesis down; somehow Platinga miss that what plausible reasoning consist of has been studied since the ancient greek and must, like math, be self-consistent; claiming our reasoning about the world is "randomly true" is like claiming elementary math like the above 7 examples are "randomly true".
Platinga, apparently aware of the obvious fact that a creature which does not use its brain is not very fit for survival (unless it studies philosophy, apparently), try to counter reality as follows:
Of course you are more likely to achieve your goals, and of course you are more likely to survive and reproduce if your beliefs are mostly true. You are a prehistoric hominid living on the plains of Serengeti; clearly you won't last long if you believe lions are lovable overgrown pussycats who like nothing better than to be petted. So, if we assume that these hypothetical creatures are in the same kind of cognitive situation we ordinarily think we are, then certainly they would have been much more likely to survive if their cognitive faculties were reliable than if they were not.
Bravo, you have just invalidated your argument in a very natural way. Oh wait, there is more:
But of course we can't just assume that they are in the same cognitive situation we think we are in. For example, we assume that our cognitive faculties are reliable. We can't sensibly assume that about this population; 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. So reflect once more on what we know about these creatures. They live in a world in which evolutionary naturalism is true. Therefore, since they have survived and reproduced, their behavior has been adaptive. This means that the neurophysiology that caused or produced that behavior has also been adaptive: it has enabled them to survive and reproduce. 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.
I think what he says is this: If we lived in serangeti, and believed lions was big friendly cats that could be petted, we would normally get eaten. But that does not invalidate his argument, since it might be the case that the lions thought we was eg. big trees. In that case both species might as well walk around in that delusion, hence his argument holds.
Since Platinga has allready failed elementary probability theory it should come as no surprice he is not aware of more advanced branches mathematics like game theory. If he were, he would know there was such a thing as a Nash-equilibrium and a litterature of when and how nash-equilibriums occur. Without getting into the technical details, the system i think he describe is not in nash equilibrium, since if any of the lions change strategy because of the natural variation in its brain (for example to think we are not trees, but juicy prunes that taste good), it will benefit. That mean that the humans now have to behave like the lions are not big friendly cats or get eaten.
The same hold for the humans, ofcourse. Now add to that that all creatures start out as brainless cells that either have to pretty much try to eat everything or die and it is pretty clear that there are no plausible evolutionary pathway to the situation he describe.
To me it seem that platinga fail at elementary probability theory, elementary inferrence and elementary game theory. Furthermore, he fail to give a simple example for a set of independent beliefs or cognitive facultis; without this there is really very little left. Before he clean those things up i wont trust him to make a coherent argument on naturalism, materalism and atheism, it sure does not seem like he has done that so far.
Sorry about the formatting, board software choked.
Your rebuttal of Plantinga's argument is persuasive, Bohm. Plantinga's evolutionary argument against naturalism uses arbitrary assignments of probability.
BTS
BTS: Im glad you think so, because i have read Platingas article 3-4 times now and i have a very hard time understanding exactly what he write.
The funny thing is that it would seem like quite an easy thing to test Platingas argument emperically: Just write a reasonably advanced artificial life simulation where each agent has some notion of "belief" on the outside world, run it, and see if the agents belief on the outside world become better or not.
In May 2009, P.Z. Meyers responded to Plantinga, at length, here:
. . .
Brains are not reliable; they've been shaped by forces which, as has been clearly said, do not value Truth with a capital T. Scientists are all skeptics who do not trust their perceptions at all; we design experiments to challenge our assumptions, we measure everything multiple times in multiple ways, we get input from many people, we put our ideas out in public for criticism, we repeat experiments and observations over and over. We demand repeated and repeatable confirmation before we accept a conclusion, because our minds are not reliable. We cannot just sit in our office at Notre Dame with a bible and conjure truth out of divine effluent. We need to supplement brains with evidence, which is the piece Plantinga is missing. He's reduced to a bogus either/or distinction. Either we are organic machines that evolved and our brains are therefore collections of random beliefs, or — and this is a leap I find unbelievable — Jesus gave us reliable minds.
. . .
http://scienceblogs.com/pharyngula/2009/05/alvin_plantinga_gives_philosop.php
