The song of the title of this post is a catchy and highly amusing piece that suggests that if we’re just mammals we should have sex. It’s sort of a low brow version of Andrew Marvell’s To his coy mistress. Instead of Time’s wingéd chariot, we should do what mammals do on the Discovery Channel. Except, humans don’t. They do something special. Think about it. We aren’t dogs, monkeys, dolphins or bowerbirds, we’re humans. We are a species (which, as I keep reminding folk, is the noun of “special”).
So when Phillip Johnson, the father of the modern intelligent design movement, attacks Christopher Hitchens for calling “great men” “mammals”, and points out:
While Hitchens never refers to the authorities on his side as “mammals,” reserving that category for those whom he wishes to belittle, it will not escape the reader that if “great men” are only mammals, then so are scientists, including the esteemed Charles Darwin and the not-quite-so-esteemed Richard Dawkins, and so, of course, is Hitchens himself. Which raises the question: Why should we take seriously any speculation by a mere mammal, or even the consensus of mammal opinion, about the origin of its species, no matter how much evidence the mammals imagine themselves to have gathered?
… we might be inclined to agree. If we’re just mammals, then we shouldn’t pay attention to Hitchens or Dawkins or Darwin, right?
I call this Darwin’s Monkey Mind Puzzle. Darwin wrote near the end of his life:
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? [Letter to William Graham, 1881]
It is recently the argument presented by Christian philosopher Alvin Plantinga against evolutionary theory – it’s self defeating. If evolution is true, then we have no warrant for thinking that evolution is true, ergo Augustine is right. Or something. I would like to discuss this a little, reprising some arguments Paul Griffiths and I have presented in a forthcoming paper. Below the fold.
First, let’s dispose of one point: Darwin’s Monkey Mind Puzzle was not aimed at debunking our knowledge of the natural world. He did not admit a fatal flaw in his own metaphysics or epistemology. The context of that quote, used by Plantinga and many others is this:
I hope that you will not think it intrusive on my part to thank you heartily for the pleasure which I have derived from reading your admirably written ‘Creed of Science,’ though I have not yet quite finished it, as now that I am old I read very slowly. It is a very long time since any other book has interested me so much. The work must have cost you several years and much hard labour with full leisure for work. You would not probably expect any one fully to agree with you on so many abstruse subjects; and there are some points in your book which I cannot digest. The chief one is that the existence of so-called natural laws implies purpose. I cannot see this. Not to mention that many expect that the several great laws will some day be found to follow inevitably from some one single law, yet taking the laws as we now know them, and look at the moon, where the law of gravitation—and no doubt of the conservation of energy—of the atomic theory, &c. &c., hold good, and I cannot see that there is then necessarily any purpose. Would there be purpose if the lowest organisms alone, destitute of consciousness existed in the moon? But I have had no practice in abstract reasoning, and I may be all astray. 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. 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?
Clearly this is about reasoning about God and design, not science. Darwin’s “horrid doubt” is whether we can know anything about God, not the world. He sees no need to imply design based on the regularity of the world. When Plantinga and others quote this passage in isolation, they are being somewhat disingenuous.**
So to the main point: if evolutionary theory is true, then are we blocked from thinking that it is true? Clearly not. If it is true then there is no contradiction with our beliefs being formed on the basis of evolutionary processes also being true. It is not a contradiction that if we evolved to believe that we should flee from tigers that we are veridically seeing tigers. But that is not Plantinga’s argument. He wants to say that we have no warrant for accepting there are tigers, because evolution does not track truth, but fitness.
It is true that, all else being equal*, evolution tracks fitness. Does this mean it doesn’t track truth? Sometime yes, when the fitter belief is untrue. Consider the Dunning-Kruger effect – the inability to appropriately measure our own competence can often lead to greater success. But that doesn’t imply that evolution never tracks truth. When fitness correlates with true beliefs, then it certainly can do this. We have a slogan:
Organisms track truth optimally if they obtain as much relevant truth as they can afford, and tolerate no more error that is needed to obtain it.
Any organism that was fitter with consistently false beliefs would be something of a philosophical miracle, akin to a P-Zombie or a Swampman. When true beliefs are causally relevant to fitness, then we might expect organisms, including those endowed with monkey minds, to be able to track truth. Species that have nervous systems respond to environmental cues that are highly relevant to their fitness: von Uexküll called this the Umwelt. The world of primate common sense is our Umwelt.
Scientific theories bootstrap on this Umwelt; we begin by testing distal claims by ordinary observation, and then extend our theoretical reach by increasingly theoretical, but tested and grounded in our Umwelt, observations, as Ian Hacking argued in Representing and Intervening. Science tracks truth because it is able to rely on some degree of truthlikeness for the observational reports that we can generate in our protoscience. [Incidentally, I think this leads to a structural realism of the kind that Psillos proposes.]
So the claim that if we are mammals we should not believe what we say (on those grounds) fails. Mammals can be right, and we have sufficient warrant to believe those things that depend upon their truth for their success. We can be mistaken, but we trade off false positive against false negatives, or type I and type II errors.
Hitchens would be wrong if he thought that being mammals debunked one set of views but not another if he held that there was something misleading to our beliefs in being a mammal; he would then be subject to a self-defeating argument, a tu quoque; but he need not think that. His opponents think that, but he can happily think that being a mammal is a state consistent with both true and false beliefs. Only those who think humans are somehow more special than just being a species makes them have that problem.
* Assuming that selection is occurring for the property in question. We should really be clear here: natural selection tracks fitness. Evolution is a far broader church than natural selection, a point noted as far back as you care to go, all the way to Darwin’s Origin, in the third edition.
** Late note: Reading through the book listed below I discover that Plantinga knows this, as he buries acknowledgement of it in a footnote. But this doesn’t excuse the mendacity, it only exacerbates it. Anyway, if he had read the letter, which has been published since the turn of the 20th century, it would have been entirely obvious, so I can only assume this is a deliberate piece of misdirection.
For an introduction to the extensive philosophical literature on Plantinga’s argument see James K Beilby, ed., Naturalism Defeated?: Essays on Plantinga’s Evolutionary Argument against Naturalism (Ithaca, NY: Cornell University Press, 2002).