According to a school of Christian apologetics called presuppositionalism, there is nothing wrong with arguing in a circle as long as it is a coherent circle. Furthermore, they say, everybody does it anyway because it is not possible otherwise to construct any world view. Up to this point, if we concede both premises, we might agree that Christianity was just as intellectually respectable as any alternative. But most presuppositionalists are evangelicals, for whom there can be no respecting of alternatives. They must identify something fundamentally wrong with any non-Christian world view. (And "Christian" to them means "evangelical Christian.")
One of today's most prominent presuppositionalists is the philosopher Alvin Plantinga of Notre Dame University. He has written a trilogy setting forth a new epistemology by which Christians can justify claiming to know that their beliefs are true. The books in the series are Warrant: The Current Debate, Warrant and Proper Function, and Warranted Christian Belief. A thorough critique would probably take at least another book if not a trilogy of its own, I'm not going to even try to begin it here. I'm going to address just one point he mentions briefly and almost offhandedly in the second and third volumes.
Plantinga claims that under any naturalistic assumption, there is no good reason to have any confidence that anything we believe is true. In particular, he argues, the process of evolution, absent any supernatural intervention, was extremely unlikely to have produced brains that could effectively distinguish truth from falsehood.The core of Plantinga's argument rests on the premise that one of the following must be true.
Plantinga argues that, since natural selection can affect only behavior and not beliefs, beliefs must be invisible to natural selection. Therefore, under naturalistic evolution any correlation between belief and truth would be only a random correlation, which we reasonably expect to be close to zero. If we are nonetheless confident that the correlation is high, then we need a supernatural explanation for it.
This relates to Plantinga's elaborate redefinition of knowledge. After surveying various problems with the prevailing notion that knowledge is justified true belief, he suggests that it be called warranted true belief and explains:
As I see it, a belief has warrant if it is produced by cognitive faculties functioning properly (subject to no malfunctioning) in a cognitive environment congenial for those faculties, according to a design plan successfully aimed at truth. (WPF, viii-ix)
Plantinga repeatedly insists that, for all the difference it makes to his epistemological views, the "design plan" could as well be implemented by Dawkins' blind watchmaker as by the God of orthodox Christianity. The problem, he says, is that the watchmaker has no reason to design organisms capable of distinguishing truth from falsehood. As long as their behavior keeps them alive long enough to reproduce, they can believe anything at all. The evidence he offers in support of this is, to put it charitably, sparse. He has two quotations, one from Darwin and the other from Patricia Churchland.
His Darwin quote is from an 1881 letter to William Graham.
But then with me the horrid doubt always arises whether the convictions of man's mind, which has been developed from the mind of the lower animals, are of any value or at all trustworthy. Would any one trust in the convictions of a monkey's mind, if there are any convictions in such a mind? (Quoted in WPF, 219)
The context does not make it clear that Darwin meant to imply what Plantinga wants him to have implied. It immediately follows this sentence and is a comment on it: "Nevertheless you have expressed my inward conviction, though far more vividly and clearly than I could have done, that the Universe is not the result of chance."
So, Darwin expressed a conviction that chance alone cannot explain the origin of the universe. We need not here discuss what if anything this implies about his theory of evolution except to point out that it is concerned with things that occurred a very long time after the universe came into existence. It sheds light on the above quotation, though, by showing it to be in effect a counterargument against reliance on such convictions insofar as they are only convictions. Considering our natural ancestry, we indeed have no reason to suppose that convictions per se are reliable. That is to say, mere certainty does not constitute knowledge. It does not matter how sure we are about something. What matters is why we are so sure.Churchland's observation is taken from a 1987 article in the Journal of Philosophy.
Boiled down to essentials, a nervous system enables the organism to succeed in the four F's: feeding, fleeing, fighting and reproducing. The principle chore of nervous systems is to get the body parts where they should be in order that the organism may survive. . . . Improvements in sensorimotor control confer an evolutionary advantage: a fancier style of representing is advantageous so long as it is geared to the organism's way of life and enhances the organism's chances of survival. Truth, whatever that is, definitely takes the hindmost. (Quoted in WPF, 218, Churchland's emphasis)
Of course skeptics have long made the point that there is no reason to suppose that natural selection ever even tried to endow any organism with a perfect truth detector. If it ever did try, it pretty obviously failed with Homo sapiens. (According to a typical Christian mythology, not even God could create sentient beings who never believed falsehoods.)
But even if we have no reason to have expected perfect cognition, should we suppose that natural selection would have been oblivious to any correspondence between our beliefs and the facts of reality? Would it really have made no difference to our ancestors' likelihood of survival whether their beliefs had any tendency to be true?
According to Plantinga, it is "currently rather popular, especially among those strongly influenced by biological science," to deny a causal relationship between beliefs and behavior. This denial, though, as Plantinga perceives it, seems to entail whatever survives of mind-body dualism.
Time . . . reports that J. M. Smith, a well-known biologist, wrote "that he had never understood why organisms have feelings. After all, orthodox biologists believe that behavior, however, complex, is governed entirely by biochemistry and that the attendant sensations–fear, pain, wonder, love–are just shadows cast by that biochemistry, not themselves vital to the organism's behavior . . . ." He could have added that (according to biological orthodoxy) the same goes for beliefs–at least if beliefs are not themselves just biochemical phenomena. (WCB, 232)
It might or might not say something relevant about Plantinga's case that his quote-mining expedition took him all the way to Time magazine. I know nothing about Smith or his field of biological expertise, whatever it is, but if he is not being quoted out of context, I smell a fear of reductionism in his comment.
Certain behaviors are uniquely appropriate in response to threats, and certain biochemical states will incline us to engage in those behaviors. Certain other behaviors are uniquely appropriate in response to trauma, and certain biochemical states will dispose us toward those behaviors. Assuming any self-awareness in the first place, it is to be expected that we will detect differences in those biochemical states and, having developed language, will label them accordingly: fear in the former case, pain in the latter. Likewise for wonder, love, and all our other feelings. While it is arguably useful in many contexts to distinguish between the biochemistry and our subjective experience of it, there is no scientific reason to pretend that our feelings have any existence independent of the chemicals. The 21st century is a little late to be thinking of the mind as anything more than what the brain does.
So it is with our perceptions of facts about our environment, both what we can see of it and, arguably more important, what we cannot see of it. We call those perceptions beliefs. Whether they are "just biochemical phenomena" is an issue more of semantics than of objective reality. They are at least biochemical phenomena, and as such they can have something to do with how we act. If you show me a certain arrangement of chemicals in a brain, I will agree that I am not looking at a belief. But I see no reason to deny the proposition that I will experience a certain belief if that particular arrangement of chemicals happens to occur in my brain.
I think it is obvious enough that beliefs do not directly cause behavior any more than feelings do. We do not always avoid what we fear, though the fear makes us want to avoid it. We do not always stop doing what causes pain, though the pain makes us want to stop doing it. We are always making decisions. A given feeling will make certain decisions more likely than others, but it will rarely if ever make any decision certain. It is likewise with beliefs. The effect of a belief might be hard to predict, but it is essentially certain that there will be an effect. If I believe that a man approaching me with a gun intends to shoot me, then that belief will definitely cause me to do something, predictable or not, that I otherwise would not do. Plantinga surely cannot think otherwise unless his understanding of causation is quite foreign to mine.
Whatever he actually thinks, Plantinga offers acausal beliefs as only one possibility. Under the possibility (purely hypothetical, he thinks) that beliefs are indeed causally linked to behavior, he next considers two subpossibilities: that they tend to cause maladaptive behavior and that they tend to cause adaptive behavior. Fortunately, he agrees that the first alternative needs no serious consideration, and so we get to the main event of Plantinga's argument. Assuming that our beliefs do affect our behavior, and given that the effects are generally adaptive, is there good reason to think that natural selection can explain this? Is it reasonable to suppose that natural selection would favor the formation of true beliefs over false beliefs?
Plantinga acknowledges that for many naturalists the intuitive answer is: Of course true beliefs are more likely to promote survival than false beliefs. While there obviously has been plenty of room for error over the millennia, our ancestors certainly had to get things right more often than not, or else we wouldn't be here arguing about it. Plantinga begs to differ, though. In his version of the Christian universe, if God doesn't make it important, then it cannot be important. As he apparently sees it, a preference for truth over falsehood can have no utilitarian basis because there can be no utilitarian difference between true and false beliefs. Instead, if in fact it is better to believe the truth than a falsehood, it can only be because God wants us to believe the truth rather than a falsehood. Nothing can make anything good except God's blessing, and nothing can make it bad except his condemnation.
Of course a false belief cannot by itself hurt anyone, and neither can a true belief by itself benefit anyone. Insofar as a belief can have any utilitarian function, it can only be by affecting behavior or, in some situations, by affecting one's physiology (e.g. the placebo effect). The following discussion will be limited to the effect of beliefs on behavior.
Plantinga stipulates that there is some component of us that produces our beliefs. Naturalists agree with that. Plantinga says that this belief-producing mechanism, whatever it is, was designed. Naturalists agree, provided "designed" is construed strictly as a metaphor.
So far as is known, the only component of human beings that can produce beliefs is the brain, and at this stage of scientific history, the only known possible metaphorical designer for the brain is the natural selection of evolutionary theory. The question then becomes whether natural selection would have noticed (metaphorically speaking) the difference between a brain that produced true beliefs and one that produced false beliefs and, if so, would have had any reason to prefer the former.
Notwithstanding the views of a certain "well-known biologist," the function of beliefs is no great mystery. Creatures with a repertoire of behaviors available to them need to make decisions from time to time. When I am faced with such-and-such a situation — let's call it situation X — I can respond by doing A, B, C, D, or etc., one of which could represent "Do nothing," then I am compelled to make a choice. I must in some way perceive that one action will be better than the others. It won't matter why I think it better, but something in my brain has to declare, rightly or wrongly, that it will be better.
We're talking about the evaluation of options. It is, in a way, what intelligence is all about. Animals without intelligence don't get to make choices. For any stimulus, their brains can produce only one response and so they can do only one thing. We owe our behavioral flexibility to our intelligence.
Intelligence, among other things, means discerning that in situation X, behavior A will bring consequence M while behavior B will bring consequence N. It also means discerning that I can do either A or B — that I actually have a choice — and it means experiencing some motivation to make that choice. It means having some notion about the future and an awareness that particular situations like M or N could exist in that future. Our brains generate those discernments, notions, awarenesses, and so on.
And they are all just various kinds of belief. I believe that A will cause M. I believe that I cannot do both A and B but must do one or the other. I believe that "tomorrow" has some kind of real meaning, that I will still be alive then, and that the situation I find myself in tomorrow will depend among other things on decisions I make today.
Beliefs like this are very useful things for a brain to produce in any organism with the physical capability of behaving consistently with them. The versatility of human behavior would not have been possible without them. What could it even mean to make a choice without having any beliefs? What sort of data would be the brain be processing, when evaluating options, if not beliefs?
Plantinga might say: Sensory data. Very well, but in the human brain those, too, are translated into beliefs. When I see a tree, I acquire a belief that there is a tree in front of me. If I were in a jungle, my sensory organs would be feeding my brain a mass of data that it would turn into a belief that I was in a jungle. If a large cat were in my visual field, I would acquire a belief that there was a large cat near me, and I would likely also acquire a belief that my life was in danger and that I should take some immediate action to reduce the danger.
In any case, Plantinga does no more than hint at a hypothetical possibility of intelligence without beliefs. Apparently stipulating the actual existence of actual beliefs, the core of his argument is against the notion that natural selection was likely to have had a preference for brains that produced true beliefs rather than false ones. Plantinga tries to demonstrate the disconnect between truth and survival in this passage:
Paul is a prehistoric hominid; the exigencies of survival call for him to display tiger-avoidance behavior. There will be many behaviors that are appropriate: fleeing, for example, or climbing a steep rock face, or crawling into a hole too small to admit the tiger, or leaping into a handy lake. Pick any such appropriately specific behavior B. Paul engages in B, we think, because, sensible fellow that he is, he has an aversion to being eaten and believes that B is a good means of thwarting the tiger's intentions.
But clearly this avoidance behavior could be a result of a thousand other belief-desire combinations . . . . Perhaps Paul very much likes the idea of being eaten, but whenever he sees a tiger, always runs off looking for a better prospect . . . . This will get his body parts in the right place so far as survival is concerned, without involving much by way of true belief. . . . 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 confuses running toward it with running away from it, believing of the action that is really running away from it, that it is running toward 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 sixteen-hundred-meter race, wants to win, and believes the appearance of the tiger is the starting signal; or perhaps. . . . Clearly there are any number of belief-cum-desire systems that equally fit a given bit of behavior where the beliefs are mostly false. (WPF, 225-226)
Very well. Those cognitive habits could have been selected for if they had promoted Paul's survival. But would they have done that?
Plantinga notes that Paul's survival depended on "tiger-avoidance behavior." And so it did, but tigers were not the only predators our ancestors had to avoid. It would have been unnecessary and inefficient for natural selection to have wired our brains with one routine for tiger avoidance, another for wolf avoidance, another for leopard avoidance, etc. A generalized predator-avoidance scheme would have been better for several reasons, mainly because only one general routine would have been needed if it was flexible enough to respond appropriately to all predators that an early hominid was likely to encounter.
Such a system would have to have reliably generated the true belief, among others, "My life is in danger" whenever Paul was confronted with a real threat to his life, because Paul would often have died when it failed to do so. Also, a false belief of endangerment could have been tolerated up to a point, but not too often. All else being equal, it is better to avoid an unreal danger than to fail to avoid a real danger, but avoidance always has its own costs, and so natural selection would have favored a belief generator that tended, when no danger was present, to generate the belief "I am safe." In particular, whenever Paul saw a harmless animal, it was to his advantage to have the belief "That animal is harmless," and natural selection should reasonably have been expected to have wired his brain accordingly.
In Plantinga's hominid scenario, although the false beliefs happened to motivate survival-promoting behavior, they did so only by chance. Any given sensory stimulus can evoke only one true belief but an infinite number of false beliefs. A belief generator that functioned with no regard for actual truth would effectively always produce a false belief. If Paul is confronting a tiger, the number of false beliefs he could have that would by chance cause adaptive behavior is a minuscule fraction of false beliefs that would be dangerous to hold. A random belief generator would probably not serve him well. It could, but the odds are long against it. Statistically speaking, he is really better off with a brain that generates beliefs that are likely to be true.
A brain that generates only true beliefs might have been
even better, but that option apparently was not available to natural selection
when it was working on our ancestors. But just because perfection was
unattainable doesn't mean there was no good reason for natural selection to try to approximate
it. It is genuinely useful to be able to tell
the difference between truth and falsehood, and if you can't do
it all the time, it is better to
do it a lot of the time than to hardly
ever do it. A brain that got the right answer more often
than not would have had a definite advantage over one that had to
rely solely on dumb luck to match behavior to environment.
References
WPF: Plantinga, Alvin. Warrant and Proper Function. New York: Oxford University Press, 1993. Oxford Scholarship Online. http://dx.doi.org/10.1093/0195078640.001.0001
WCB: Plantinga, Alvin. Warranted Christian Belief. New York: Oxford University Press, 2000. Oxford Scholarship Online. http://www.oxfordscholarship.com/oso/public/content/philosophy/0195131932/toc.html