Wednesday, November 5, 2008
Truth and Usefulness
When Alvin Plantinga and others developed what may be called the Argument from Reason Against Evolutionary Naturalism, my expectation was that proponents of evolutionary psychology would work flat out to explain why Quine and Dennett were right in claiming that natural selection is a good explanation of the reliability of human reasoning.
Oddly, this is not the case. In How the Mind Works (p. 305), Steven Pinker insists that "our brains were shaped for fitness, not for truth." In other words, our cognitive capacities, including reason, are there because they are useful in the Darwinian sense of promoting the flourishing of our "selfish" genes.
The obvious problem with this is that what natural selection tests directly is our behavior, and false beliefs are just as good as true ones provided that they produce adaptive behavior, e.g. so long as it makes me run away from lions, the false belief that I am confronted with a shrubbery will be selected for. And there are surely many more false beliefs than relevant true ones about lions to choose from, so it seems it is always more likely for me to be motivated by false beliefs connected to adaptive behavior than by true and relevant beliefs that would actually provide an intelligible reason for that behavior.
Lewis Wolpert does the same thing. In Six Impossible Things Before Breakfast, he writes that (p. 140) "our brains contain a belief generating machine, an engine that can produce beliefs with little relation to what is actually true."
Later in the same book, and with no discernible sense of irony, or epistemic danger, he says (p. 216), "Science provides by far the most reliable method for determining whether one's beliefs are valid." Well, but the "scientific method" consists of beliefs generated by this unreliable engine. And what is worse, supposing that direct relevance to survival somehow could increase the probability that our beliefs are true, this certainly would not grant reliability to abstract beliefs in science and philosophy having nothing to do with survival.
Again, one thinks the evolutionary psychologist would worry--be afraid of the epistemic lions, as it were. But these lions are only mentioned in passing--as if they were shrubberies. Writes Pinker again (304):
"Our ancestors encountered certain problems for hundreds of thousands or millions of years--recognizing objects, making tools, learning the local language, finding a mate, predicting an animal's movement, finding their way--and encountered certain other problems never--putting a man on the moon...proving Fermat's last theorem."
Here we have a theory like the one D. A. Carson has called "hard postmodernism," that takes itself all of the way to epistemic self-destruction. The theory implies that theories such as itself have no reliable basis. How then can the evolutionary psychologist recommend evolutionary psychology (or the broader evolutionary naturalism on which it depends ) with any credibility? Isn't this just like the hard postmodernist's self-refuting claim that there are NO metanarratives (it is true of all narratives that they are not metanarratives)?
Even more odd is the fact that when considering supernatural religious beliefs, evolutionary psychologists often claim, in effect, that since these beliefs are useful (for social cohesion, health or whatever) they aren't true! Of course this is a fallacy, but one would think they would be concerned with the implications for their own worldview. Just as it is a fallacy to argue useful, therefore true, it is equally a mistake to argue useful, therefore false, which would mean giving up arithmetic, logic and the scientific method. It is a bizarre spectacle to see thinkers attempting to apply universal acid selectively. When they claim that scientific claims have special reliability because of the way they are tested, they forget that they are presupposing the very use of logic (the experimental method) whose reliability is in question.
Aside from the lack of hard evidence for its claims, it seems to me that evolutionary psychology is showing itself to be fraught with problems of internal incoherence, and can only be upheld by a scrupulous doublethink which masks as shrubberies the epistemic lions it has unleashed, though they seem quite ready and willing to devour it.
Oddly, this is not the case. In How the Mind Works (p. 305), Steven Pinker insists that "our brains were shaped for fitness, not for truth." In other words, our cognitive capacities, including reason, are there because they are useful in the Darwinian sense of promoting the flourishing of our "selfish" genes.
The obvious problem with this is that what natural selection tests directly is our behavior, and false beliefs are just as good as true ones provided that they produce adaptive behavior, e.g. so long as it makes me run away from lions, the false belief that I am confronted with a shrubbery will be selected for. And there are surely many more false beliefs than relevant true ones about lions to choose from, so it seems it is always more likely for me to be motivated by false beliefs connected to adaptive behavior than by true and relevant beliefs that would actually provide an intelligible reason for that behavior.
Lewis Wolpert does the same thing. In Six Impossible Things Before Breakfast, he writes that (p. 140) "our brains contain a belief generating machine, an engine that can produce beliefs with little relation to what is actually true."
Later in the same book, and with no discernible sense of irony, or epistemic danger, he says (p. 216), "Science provides by far the most reliable method for determining whether one's beliefs are valid." Well, but the "scientific method" consists of beliefs generated by this unreliable engine. And what is worse, supposing that direct relevance to survival somehow could increase the probability that our beliefs are true, this certainly would not grant reliability to abstract beliefs in science and philosophy having nothing to do with survival.
Again, one thinks the evolutionary psychologist would worry--be afraid of the epistemic lions, as it were. But these lions are only mentioned in passing--as if they were shrubberies. Writes Pinker again (304):
"Our ancestors encountered certain problems for hundreds of thousands or millions of years--recognizing objects, making tools, learning the local language, finding a mate, predicting an animal's movement, finding their way--and encountered certain other problems never--putting a man on the moon...proving Fermat's last theorem."
Here we have a theory like the one D. A. Carson has called "hard postmodernism," that takes itself all of the way to epistemic self-destruction. The theory implies that theories such as itself have no reliable basis. How then can the evolutionary psychologist recommend evolutionary psychology (or the broader evolutionary naturalism on which it depends ) with any credibility? Isn't this just like the hard postmodernist's self-refuting claim that there are NO metanarratives (it is true of all narratives that they are not metanarratives)?
Even more odd is the fact that when considering supernatural religious beliefs, evolutionary psychologists often claim, in effect, that since these beliefs are useful (for social cohesion, health or whatever) they aren't true! Of course this is a fallacy, but one would think they would be concerned with the implications for their own worldview. Just as it is a fallacy to argue useful, therefore true, it is equally a mistake to argue useful, therefore false, which would mean giving up arithmetic, logic and the scientific method. It is a bizarre spectacle to see thinkers attempting to apply universal acid selectively. When they claim that scientific claims have special reliability because of the way they are tested, they forget that they are presupposing the very use of logic (the experimental method) whose reliability is in question.
Aside from the lack of hard evidence for its claims, it seems to me that evolutionary psychology is showing itself to be fraught with problems of internal incoherence, and can only be upheld by a scrupulous doublethink which masks as shrubberies the epistemic lions it has unleashed, though they seem quite ready and willing to devour it.
Labels: alvin plantinga, epistemology, philosophy of mind, reason and worldviews
