In a Philadelpha Inquirer piece on whether Catholics really accept the scientific notion of evolution, columnist Faye Flam interviewed me about the supposed evolutionary “specialness” of humans:
Many biologists are not religious, and few see any evidence that the human mind is any less a product of evolution than anything else, said Chicago’s Coyne. Other animals have traits that set them apart, he said. A skunk has a special ability to squirt a caustic-smelling chemical from its anal glands.
Our special thing, in contrast, is intelligence, he said, and it came about through the same mechanism as the skunk’s odoriferous defense.
I wasn’t really trying to be provocative here: I did have a pet skunk for several years, and it was the first thing that came to mind. But as soon as I said this, I knew that comparing the human mind to a skunk butt would tick people off.
Sure enough, Vincent Torley at the Discovery Institute doesn’t like it at all. At the intelligent-design website Uncommon Descent, he responds to both my claim and Stephen Hawking’s recent statement about human mortality, “I regard the brain as a computer which will stop working when its components fail. There is no heaven or afterlife for broken down computers; that is a fairy story for people afraid of the dark. ”
Torley makes three arguments:
1. The human mind is not like a computer. Torley reprises Chris Chatham’s list of differences between computers and human minds: computers are digital, minds analogue, there’s no distinction between hardware and software in the brain, the brain is often self-repairing while computers are not, and so on. Toley concludes:
The brain-computer metaphor is, as we have seen, a very poor one; using it as a rhetorical device to take pot shots at people who believe in immortality is a cheap trick. If Professor Hawking thinks that belief in immortality is scientifically or philosophically indefensible, then he should argue his case on its own merits, instead of resorting to vulgar characterizations.
Poor Torley; he wants to believe in the afterlife so badly that he dismisses Hawking’s statement as a “rhetorical” device. In fact it is not. Hawking’s point was not, of course, that the brain works precisely like a computer—it was that the brain is a meat machine that cranks out thoughts and emotions, and when the brain dies, so does its products. Hawking is alluding to the very real observations that damaged minds produce damaged thoughts, that you can influence behavior and personality by material interventions in the brain, that you can eliminate consciousness with drugs and reinstate it by withholding those drugs, and to the lack of evidence for any soul or immortal component that can survive the death of the brain. It’s completely irrelevant whether or not the brain works exactly like a computer.
2. Human minds are totally not like skunk butts. Here Torley relies on recent biological discoveries: a paper by Dorus et al. in Cell showing that the human lineage showed accelerated evolution of genes involved in the nervous system, and a news article in Science claiming that the human lineage shows accelerated evolution not just of gene sequence, but of gene expression.
Well, so what? The skunk’s system of chemical defense evolved by natural selection (and nobody’s yet looked at the genes involved—maybe their evolution was fast as well), and so did the human mind. Just because genes involved in building our brain evolved rapidly compared to genes in primates or rodents is not evidence for a fundamental difference between brains and skunk butts. Some traits evolve fast, others evolve slowly. No biggie. But Torley plumps for God here:
I would argue that these changes that have occurred in the human brain are unlikely to be natural, because of the deleterious effects of most mutations and the extensive complexity and integration of the biological systems that make up the human brain. If anything, this hyper-fast evolution should be catastrophic. We should remember that the human brain is easily the most complex machine known to exist in the universe. If the brain’s evolution did not require intelligent guidance, then nothing did.
He’s right; nothing did. All Torley is saying here is that brains are complex and could not have evolved by Darwinian processes—both because they are complex and because most mutations are deleterious, which would make rapid evolution of the brain “catastrophic.”
That argument is nonsense. So long as advantageous mutations occur, regardless of their rarity, natural selection can build a complex brain without “catastrophe.” And it had about five millions years to turn a chimp-sized brain into ours. Just looking at volume, and assuming an ancestral brain of 500 cc, a modern brain of 1200 cc, and a generation time of 20 years, that’s a change in brain volume of 0.0028 cc/generation, or an average increase of 0.00056% per generation. Where’s the evidence that this change—at least in volume—was too fast to be caused by selection? We know that current observations of selection, such as that seen in beak size in Darwin’s finches, can be much stronger than this without catastrophic effects! The finches, after all, are still here, and behaving like finches.
3. The human mind cannot be the same as the human brain. Torley leans on the work of Edward Feser here, who has argued that neurochemical activity could never result in thoughts and words that had inherent meaning:
Feser points out that our mental acts – especially our thoughts – typically possess an inherent meaning, which lies beyond themselves. However, brain processes cannot possess this kind of meaning, because physical states of affairs have no inherent meaning as such. Hence our thoughts cannot be the same as our brain processes.
I’ll leave this one to the philosophers, except to say that “meaning” seem to pose no problem, either physically or evolutionarily, to me: our brain-modules have evolved to make sense of what we take in from the environment. And that’s not unique to us: primates surely have a sense of “meaning” that they derive from information processed from the environment, and we can extend this all the way back, in ever more rudimentary form, to protozoans. Saying that thoughts have meanings that “lie beyond themselves” simply assumes what Torley’s trying to prove.
And the lesson Torley draws from all this? You know what it is, and it shows with crystal clarity that all this intelligent-design palaver is motivated simply by a love of Jesus:
The fact that rational choices cannot be identified with, caused by or otherwise explained by material processes does not imply that we will continue to be capable of making these choices after our bodies die. But what it does show is that the death of the body, per se, does not entail the death of the human person it belongs to. We should also remember that it is in God that we live and move and have our being (Acts 17:28). If the same God who made us wishes us to survive bodily death, and wishes to keep our minds functioning after our bodies have cased to do so, then assuredly He can. And if this same God wishes us to partake of the fullness of bodily life once again by resurrecting our old bodies, in some manner which is at present incomprehensible to us, then He can do that too. This is God’s universe, not ours. He wrote the rules; our job as human beings is to discover them and to follow them, insofar as they apply to our own lives.