Sunday, August 28, 2005

Australopithecus: an evolving threat

Richard Dawkins, the prominent defender of Darwinism, has a striking thought experiment. Imagine, he says, that you are standing in east Africa, on the shore of the Indian Ocean, facing north. In your left hand you hold the right hand of your mother, who is standing beside you. She, in turn, is holding the hand of her mother, to her left, and her mother in turn (we have to do some hanky panky with time) is holding her mother’s hand, and so on and on. This chain of women, mothers and daughters, stretches some 300 miles, or less than 500 kilometers, inland, at which point there is a mother who has turned ninety degrees to face back toward the ocean. In her right hand she holds the hand of the daughter from whom you are descended. In her left hand, she holds the hand of a second daughter, who stands facing her first daughter, sister facing sister. This second daughter holds in her left hand the hand of her daughter, who holds the hand of her daughter, and so on—a chain facing the first chain (cousins facing cousins) and stretching all the way back down to the ocean. At the end of this second chain, facing you, is your distant cousin: a modern chimpanzee.

Since Darwin, many people have been distinctly unhappy with the idea that we are descended from non-human animals—and that we in fact are apes. In a famous debate at Oxford in 1860, Bishop Samuel Wilberforce asked Thomas Henry Huxley (who became known as “Darwin’s Bulldog”) whether it was through his grandfather or his grandmother that he claimed descent from a monkey. Darwinian evolution threatens the doctrine of human exceptionalism, the idea that human beings stand at the pinnacle of creation. More than simply a claim about the superior mental powers of Homo sapiens, human exceptionalism holds that humans possess a unique moral worth that makes it unacceptable to treat them as mere means to the ends of others, but permits humans to use non-humans as mere means to human ends. Wesley J. Smith argues that those who reject human exceptionalism, including proponents of animal rights and many bioethicists and proponents of biotechnology, open the door to the elimination of human rights. "I mean, if we are merely another animal in the forest, that is precisely how we will act." This is also the claim made by Jesuit philosopher James B. Reichmann in Evolution, Animal "Rights", and the Environment.

There is no contradiction between believing in evolution and believing in God. (The great historian of science, Joseph Needham, was a Christian Marxist who believed that dialectical materialism—or dialectical naturalism, as he preferred to call it—was God’s way of working in the world.) But the theory of evolution deals a hard blow to human exceptionalism by showing that species have arisen through gradual changes, and that humans are related by descent to other forms of life that often closely resemble them. The hominid relatives of modern humans, including Australopithecus and earlier Homo species cannot easily be excluded from the moral community. Would it have been okay to eat or enslave Neanderthals—members of a hominid species with brains larger than ours, who died out about 30,000 years ago? (Perhaps our ancestors did just that; there is some speculation that the Neanderthals may have been victims of genocide.) What if tomorrow we discover some isolated community in the Alps whose living members are part Homo sapiens and part Homo neanderthalensis? Would they qualify for moral rights? Would it be a hideous crime to eat or experiment upon individuals who were 51% sapiens, but fine and dandy to eat or experiment upon their next-door neighbours who were only 49% sapiens?

Immanuel Kant claimed that humans have a special moral worth because they are rational beings. But even if we grant full moral status to Neanderthals on the basis of their reasoning powers and presumed moral agency, there’s a problem. Many humans (the very young, the severely mentally handicapped) are not rational beings, and indeed have lesser mental abilities than many non-humans. Darwinian evolution, which rejects the notion of rigid biological groupings of organisms, each with its immutable essence, implies “moral individualism”, the idea that the moral standing of beings depends on their individual characteristics rather on their membership in some class of beings (e.g., species). (See James Rachels, Created from Animals: The Moral Implications of Darwinism.) In other words, a pig or dog whose relevant mental capacities (reasoning powers, autonomy, emotional responses, or whatever is deemed key) exceed those of a mentally handicapped human, ought to be accorded equal or higher moral standing. Dawkins’ thought experiment above is part of a piece he wrote for The Great Ape Project, whose aim is to have the other great apes (chimpanzees, gorillas, and orangutans) granted legal rights to life, liberty, and freedom from torture.

The fall-back position for the exceptionalist is to claim that humans have a special moral worth just because they are human. Thus Wesley J. Smith says, “Human life has ultimate value simply and merely because it is human.” But how does one defend such a claim, which on the surface appears to be arbitrary and no different from saying, “Men are superior to women simply and merely because they are men”? Indeed, without further backing, the claim of human exceptionalism leads to nonsensical conclusions. One way of giving the claim the backing it needs is to hold that God has intervened in nature to endow humans with unique moral worth, perhaps by giving them immortal souls or perhaps by announcing, “because I’m God and I say so.” One might try to square such divine intervention with evolution by imagining that God specially endows each human being at conception with such worth, or intervened at some moment in the past (say, 50,000 years ago) with a blanket endowment of unique worth for Homo sapiens; but any such claim must remain a matter of pure faith. On the other hand, if it can be persuasively argued on the basis of biological evidence that the species Homo sapiens was independently designed, or at least is the culmination of a designed process, then the case for human exceptionalism acquires a modicum of plausibility.

Guess what. It turns out that Wesley J. Smith, denouncer of animal rights and the prospect of genetically-engineered human-animal chimeras, is a prominent member of the Discovery Institute, the Seattle-based organization that is at the forefront of the campaign to get Intelligent Design accepted as a legitimate scientific theory. The belief that life on this world has in some way been designed by intelligence—God, or space aliens, or even human virtual-reality technicians in the real world of the thirty-third century—can be compatible with a belief in Darwinian evolution. So why the vehemence of the current public debate? Although Darwinism is not beyond scientific criticism, historically its rejection has been fuelled more by politics and culture than by science. Intelligent Design theory is not simply a claim about the existence of a Designer based on the alleged inadequacy of natural selection to account for the origin of species. It is a bulwark that is being constructed to defend the doctrine of human exceptionalism.

I close this post with the words of Thomas Henry Huxley (1825-1895):
When I reached intellectual maturity, and began to ask myself whether I was an atheist, a theist, or a pantheist; a materialist or an idealist; a Christian or a freethinker, I found that the more I learned and reflected, the less ready was the answer; until at last I came to the conclusion that I had neither art nor part with any of these denominations, except the last. The one thing in which most of these good people were agreed was the one thing in which I differed from them. They were quite sure that they had attained a certain “gnosis” -- had more or less successfully solved the problem of existence; while I was quite sure I had not, and had a pretty strong conviction that the problem was insoluble. And, with Hume and Kant on my side, I could not think myself presumptuous in holding fast by that opinion. ...

Agnosticism, in fact,
is not a creed, but a method, the essence of which lies in the rigorous application of a single principle. That principle is of great antiquity; it is as old as Socrates; as old as the writer who said, “Try all things, hold fast by that which is good”; it is the foundation of the Reformation, which simply illustrated the axiom that every man should be able to give a reason for the faith that is in him, it is the great principle of Descartes; it is the fundamental axiom of modern science. Positively the principle may be expressed: In matters of the intellect, follow your reason as far as it will take you, without regard to any other consideration. And negatively: In matters of the intellect, do not pretend that conclusions are certain which are not demonstrated or demonstrable. That I take to be the agnostic faith, which if a man keep whole and undefiled, he shall not be ashamed to look the universe in the face, whatever the future may have in store for him.

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