Evolution is a lot more subtle than it is given credit for. In 1987, Patricia Churchland, expressed a rather common take when she wrote “The principle chore of nervous systems is to get the body part where they should be in order that the organism may survive.” (Whoa! Survival?! Isn’t reproduction the fundamental variable?) A tale of solitary organisms fleeing predators, finding scarce food, and pouncing on potential mates. No time for thought and reflection: “Truth, whatever that is, definitely takes the hindmost.” Rarely is it noted (even by Churchland herself) that in the short space between those two sentences, she wrote “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.” A salutary turn, but then a reversion to that emphasis on survival. No thought that believing the truth can lead to speaking the truth, which, given a social “way of life” might be behaviour with positive evolutionary consequences.
In 1993, Alvin Plantinga seized on Churchland in an attempt to show that the theory of evolution is incompatible with naturalism. That is pretty cheeky, don’t you think? Could he be right?
The argument goes like this:
C. The function of our cognitive faculties is to give us access to the truth.
~E. Evolution is unlikely (by itself) to produce cognitive faculties that give us access to the truth.
~N: Something other than evolution was (at least partially) responsible for the production of our cognitive faculties.
We should all applaud C (though regrettably a few of us do not). Perhaps we can take on board the Kahneman thesis that we have a system of belief formation that is fast but unreliable. But this should be qualified by the Kahneman posit of a slower, hard-to-use system that is able to correct the erroneous beliefs that the first system produces. Similarly, we should perhaps give credence to the thesis of Sperber and Mercier that the solitary subject normally reasons in highly unreliable ways. But we should temper that by recognizing that (as S and M posit) in groups we become reasonable because dialogue and argument produce reliable reasoning. One way or another, humans have a capacity to reason reliably . . . and that is the function of cognition, or some part of it.
So to rescue N (or naturalism), we must rely on the claim that evolution could be the sole originator of our reliable cognitive faculties, i.e., on rejecting E. And here, Plantinga’s pivot is to argue that the causal relation between beliefs and survivalist behaviour is far from straightforward. Discovering prime numbers doesn’t lead to survival-inducing behaviour, and the latter is disconnected from true belief.
And then this Ramsay argument:
- Evolution cares about behaviour, not thought.
- Beliefs are evolutionarily adaptive only insofar as they produce adaptive behaviour.
- But beliefs produce behaviour only in conjunction with desire, and
- There are an indefinite number of belief-desire pairings that will produce any given behaviour, adaptive or not.
- Very few of the adaptive belief-desire pairings as per 4 contain true beliefs.
- Therefore, the probability of evolution producing true beliefs is low.
The argument is a transformation of more familiar arguments for the indeterminacy of belief attribution. It’s hard to attribute belief on the basis of action because a non-standard desire will produce the same action together with a different belief. Rob runs away from a tiger. Perhaps he thinks that running away is the best way to make friends with it. A wrong belief, coupled with a destructive desire, leads to survival.
Plantinga’s twist: it’s hard to predict what beliefs (or belief-producing mechanisms) evolution will produce if left to itself because together with non-standard desires (or desire-producing mechanisms) non-standard beliefs will produce the same behaviour . . . and it is behaviour that evolution cares about. Rob survives despite his false belief. He got away from the tiger.
Two points, very briefly. First: Most evolutionists realize that adaptive behaviour can comprise a good bit more than fleeing tigers. A very simple observation: if you know p you are more likely to assert p. Asserting that p is behaviour, and in the context of group dynamics it may be very useful for survival to assert true things. As well, the capacity to divine non-obvious truths is sexually attractive. Good platform for sexual selection.
Second: let’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.