Thoughts in a Haystack

There has been a flurry of renewed interest in Alvin Plantinga's "evolutionary argument against naturalism" (EAAN). Mohan Matthen, a professor of philosophy at the University of Toronto has posted a critique at New APPS: Art, Politics, Philosophy, Science:

[L]et's think about special purpose cognition vs general purpose cognition. Fleeing from predators can make organisms evolve special purpose detectors. These probably should not be very accurate, since an excess of false positives helps survival: its safer than a more accurate detector with the occasional false negative. But what about general purpose detector? Remember Rob, who runs away from tigers because he feels that is the best way to make friends—this enables him to escape the consequences of his disastrously false belief that tigers make good playmates. But if this is a general purpose attitude, he also runs away from potential mates because he believes that this is the best way to hook up with them. Evolutionarily, not so good.

Here is something the survivalists overlook. The senses are general purpose learning systems; inference and rationality helps us use them to come to know about our surroundings. Of course, we have special purpose cognition too, but these usually feed into autonomous behavioural systems that are not run by and don't produce beliefs. Belief is irrelevant to a rabbit freezing at the (often false) indication of a predator. Belief means everything to a young man or woman who is taking leadership of a group on a trek to find a better life.

Nicholas McGinnis at Engaging Science, the blog of the Rotman Institute of Philosophy at the University of Western Ontario (go canucks!), points out:

The problem is that an imago dei epistemology does not seem to follow from God's nature but God's free exercise of will. We therefore have a parallel problem: of all the infinite things God could do, how certain are we that he would choose to create in his image? Contrast to evolution: of all the infinite things that could evolve, why reliable faculties? The difference is that I know what kind of constraints, observations, and experiments might lead me to think evolution did lead to reliable faculties, but, short of direct personal revelation, I have no idea how to confirm imago dei.

TomS made much the same point some time ago here.

McGinnis also points out that the Stanford Encyclopedia of Philosophy (SEP), which I have always thought was reliable, gives Plantinga a pass on the EAAN and his promotion of Michael Behe's "irreducible complexity" nonsense:

As a side-note, while re-reading Plantinga's SEP entry on 'Religion and Science' I am reminded of how bizarre and parochial the article is: it is not a discussion of the complex relationship between science and religion in the history of philosophy, nor an overview of the current state of affairs in the literature. Rather, it functions as a showcase for Plantinga's own views.

There is no discussion of some seminal and influential concepts–such as Gould's 'non-overlapping magisteria'–nor any mention of, say, the relationship between Islam and science. Instead we have enthusiastic citations of intellectually dishonest creationist frauds like Michael Behe, complete with summaries of discredited arguments about the bacterial flagellum and blood clotting meant to offer proof positive of the spurious, unscientific notion of 'irreducible complexity'. Writes Plantinga, "not only do [these examples] challenge Darwinism; they are also, [Behe] says, obviously designed: 'their design is about as obvious as an elephant in a living room.'" I cringe to read these words in the discipline's most publicly-visible reference source.

[Cough] Amen!

Labels: Plantinga's Naturalism

Link - Posted by John Pieret @ 12:54 PM 14 comments

I recently took some interest in Alvin Planting'a evolutionary argument against naturalism, posting here, here and here on it.

British Philosopher Stephen Law has taken on a portion of Plantinga's argument, that Law calls the belief-cum-desire component, and, I think, neatly demolishes it. Very briefly, Plantinga argues that our cognitive beliefs are not directly adaptive but only our behavior is. But our behavior is not just a result of our beliefs but also of our desires. That means, Plantinga contends, that, on a naturalistic evolutionary account, we cannot say that our beliefs are reliable because false beliefs can, nonetheless, result in adaptive behavior. Therefore, if one of your beliefs is that naturalism is true, that belief is self-defeating.

One of Plantinga's illustrations is as follows:

So suppose Paul is a prehistoric hominid; a hungry tiger approaches. Fleeing is perhaps the most appropriate behavior: I pointed out that this behavior could be produced by a large number of different belief-desire pairs. To quote myself: 'Perhaps 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. This will get his body parts in the right place so far as survival is concerned, without involving much by way of true belief.

[W]hen we turn from beliefs to belief-producing cognitive mechanisms of the sort with which we are equipped (e.g. reason, perception, memory), it is no longer clear that there are many (indeed, any) unreliable versions of such mechanisms that, by virtue of unguided evolution pairing them with certain hard-wired desires, will nevertheless result in the sort of sophisticated patterns of adaptive behaviour we exhibit.

Nevertheless, the belief-cum-desire argument, even if not indispensable to Plantinga's larger project, nevertheless constitutes one of the most interesting and initially intuitively appealing parts of Plantinga's larger case, and its loss is significant.

Labels: Plantinga's Naturalism

Link - Posted by John Pieret @ 10:39 AM 5 comments

TomS, in a comment, has made an important point about Alvin Plantinga's evolutionary argument against naturalism:

I would suggest that Intelligent Design, as it refuses to make any statement about the intelligent designer(s), would have the same problem that evolution supposedly has.

That is, ID has no guarantee for the reliability of knowledge. Therefore, using the logic of Plantinga, ID is as incompatible with non-naturalism as evolution is with naturalism.

We don't know that intelligent designer(s) would be at all interested in, or capable of, designing our brains (or minds, whatever it is that they design) to know truths.

Plantinga's argument is basically that it is not rational to believe that philosophical naturalism is true, while it is rational to believe in "traditional theism," because we can't be sure our cognitive faculties are delivering truth if we evolved without aid from God but can presume that God, making us in his/her/its image, would give us cognitive faculties that deliver truth, even if our minds "have developed from those of the lower animals." But as William Dembski has said in Debating Design:

... ID never claims that an empirically based design inference by itself establishes the identity, character or motives of the designer.

Thus, by Plantinga's argument, ID, which admits that evolution occurs but claims that an unknown Designer of unknown motives and capabilities guided it, is as irrational as philosophical naturalism supposedly is, since we cannot presume that this Designer had any motive or ability to give us reliable cognitive faculties.

Quod erat demonstrandum.
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Labels: Plantinga's Naturalism

Link - Posted by John Pieret @ 6:36 AM 12 comments

For those interested in Alvin Plantinga's evolutionary argument against naturalism, the Wikipedia article I referenced before mentioned that Branden Fitelson and Elliott Sober had criticized Plantinga's Bayesian argument. I've found the article online at Professor Sober's website.

The arguments are fairly technical but they come to the same conclusion that I did:

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.

Consider what Plantinga and other theists have to believe in order to be in any better position than naturalists. First of all, as Fitelson and Sober point out, Plantinga maintains that naturalism and "traditional theism" are the only two "significant alternatives," i.e. that there are no other possibilities worth considering. That has certain consequences: the probability of our cognitive faculties being reliable is high if and only if God exists (or else theists are equally subject to the evolutionary scenario that Plantinga spins). But why should they believe God exists unless whatever arguments in favor of his/her/its existence (even assuming the arguments themselves are good) are the result of reliable cognitive faculties? In other words, the probability of God existing is high if and only if human cognitive faculties are reliable. And the probability of human cognitive faculties are reliable is high if and only if God exists.

It seems to me that such tight circularity is every bit as much a "defeater" of the rationality of theism as the alleged poverty of evolutionarily derived cognitive faculties could possibly be to naturalism.
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Labels: Plantinga's Naturalism

Link - Posted by John Pieret @ 2:34 PM 2 comments

PZ Mxyzptlk has a post on Alvin Plantinga's evolutionary argument against naturalism, as summarized in an article at Christianity Today.

I think PZ underestimates the philosophical sophistication of the argument (which, of course, does not mean it is either correct or true). The Wikipedia article on the argument shows that there is a lot of nuance going on and, indeed, an entire collection of objections to the argument and Plantinga's responses has been published.

I won't pretend to have studied Plantinga's argument or the responses thereto beyond the Wikipedia article and a few expositions of it by Plantinga and other theists, so my thoughts on it are best described, charitably, as preliminary.

PZ states:

In Plantinga's world, if we queried the inhabitants with some simple question, such as, "Is fire hot?", 50% would say no, and 50% would say yes. This world must be populated entirely with philosophers of Plantinga's ilk, because I think that in reality they would have used experience and their senses to winnow out bad ideas, like that fire is cold, and you'd actually find nearly 100% giving the same, correct answer. Plantinga does not seem to believe in empiricism, either.

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. ...

... 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.

Plantinga states that he is not attacking the theory of evolution,[16] which only yields the self-contradiction when connected with philosophical naturalism but is not equally inconsistent with theism.

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.

The problem, as several thinkers (C. S. Lewis, for example) have seen, is that naturalism, or evolutionary naturalism, seems to lead to a deep and pervasive skepticism. It leads to the conclusion that our cognitive or belief-producing faculties—memory, perception, logical insight, etc.—are unreliable and cannot be trusted to produce a preponderance of true beliefs over false. ...

Clearly this doubt arises for naturalists or atheists, but not for those who believe in God. That is because if God has created us in his image, then even if he fashioned us by some evolutionary means, he would presumably want us to resemble him in being able to know; but then most of what we believe might be true even if our minds have developed from those of the lower animals.

(First, an amusing aside: footnote [7] is an acknowledgment of the assistance of someone else in doing those calculations. He needed help from an expert to multiply simple probabilities? Does being a philosopher mean you're incapable of tapping buttons on a calculator?)

Caerleon, North Wales, June 19, 1869.

I am much obliged to your Correspondent¹ of June 5 for having pointed out a great error in my 'Origin of Species,' on the possible rate of increase of the elephant. I inquired from the late Dr. Falconer with respect to the age of breeding, &c., and understated the data obtained from him, with the intention, vain as it has proved, of not exaggerating the result. Finding that the calculation was difficult, I applied to a good arithmetician; but he did not know any formula by which a result could easily be obtained; and he now informs me that I then applied to some Cambridge mathematician. Who this was I cannot remember, and therefore cannot find out how the error arose. From the many familiar instances of rapid geometrical increase, I confess that, if the answer had been thirty or sixty million elephants, I should not have felt much surprise; but I ought not to have relied so implicitly on my mathematical friend. I have misled your Correspondent by using language which implies that the elephant produces a pair of young at each birth; but the calculation by this assumption is rendered easier and the result but little different. A friend has extended your Correspondent's calculation to a further period of years. Commencing with a pair of elephants, at the age of thirty, and assuming that they would in each generation survive ten years after the last period of breeding—namely, when ninety years old—there would be, after a period of 750 to 760 years (instead of after 500 years, as I stated in 'The Origin of Species'), considerably more than fifteen million elephants alive, namely, 18,803,080. At the next succeeding period of 780 to 790 years there would be alive no less than 34,584,256 elephants.

CHARLES DARWIN

Labels: Plantinga's Naturalism

Link - Posted by John Pieret @ 1:14 PM 7 comments