Sunday, December 06, 2009

History and Evolutionary Theory

According to orthodox mythology, Galileo was something of a martyr for the cause of science and human enlightenment. After the publication, in 1632, of his Dialogo (its full title in English, Dialogue Concerning the Two Chief World Systems, Copernican and Ptolemaic), he was condemned at Rome the following year. The way the story if often told, his only offense was to challenge the dominant scientific orthodoxy of his day, which claimed that the earth was motionless. The Church, it is often claimed, held this to be a theological truth not open to challenge by mere laymen, and his trial was, accordingly, one for heresy. He was forced to abjure his belief that the earth moved, and to spend the rest of his life under house arrest. As if to make the story even more dramatic--and to add a nice kick on behalf of the "good guys" who might be reading this story nowadays--it is also reported that he muttered "And yet it moves" under his breath after his public proclamation that the earth is motionless.

High drama--drama that would be rather spoiled if the whole story were told sine ira et studio. The story provides some comfort to those who would defend a kind of secular humanism, in which the saints are such figures as Galileo, Giordano Bruno, and their ilk. Comfort because, in our own enlightened times, we see the scientific community as the victors, the Catholic Church as the loser, in this earliest of modern-era culture wars. Indeed, when John Paul the Great offered up an apology for the condemnation of Galileo there was much rejoicing on the part of those who think that the Church has much to answer for in terms of her opposition to scientific enlightenment. The apology was actually seen, in some quarters, as some sort of a victory for the humanist side, if you can believe it, though that sort of thinking is of a pace with those who so often fail so utterly to understand anything about the Faith.

A similar culture war rages in our own day, this time not between The Church and The Astronomers but between The Church and The Biologists. In the present conflict, a few humanist biologists are pitting (in their own imaginations) the theory of evolution by natural selection against the truth of the Faith, in the rather vain hope that any rational person accepting the truth of the former will, by some strange (bio)logical necessity, have to reject the truth of the latter. There are a few humanist biologists who think this way who are not otherwise insane, so it is at least worth thinking about what on earth could possibly give rise to such a risible belief in a putatively rational person. My own hunch is that it is largely an accident of history.

The accident that I have in mind is the fact that Darwin did his work in the 19th century, while progress in molecular biology did not really occur until the 20th century. I think that if these two historically contingent facts were reversed, we would not see the present conflict. Darwin's idea was a big one: a grand explanatory theory that was sent forth fully formed into a public that was just beginning to grapple with the social and political pressures of materialism, industrialization, and internationalism. The perceived threat to religious belief was, it seems to me, already incubating on a number of fronts. When The Origin came along it was not a particularly revolutionary work from a theological point of view, but the popular culture was prepared to receive it as such principally because it came along at a time when religious folks were already beginning to feel besieged. If you add to this the rise, forty years later, of Protestant fundamentalism and the rather bizarre belief in the literal truth of the mythological cosmology at the start of the book of Genesis, along with the fact that the majority of Americans at the time (indeed, to this day) were Protestants who were also Americans committed to the view that every opinion is sacred, it is not all that surprising that things have evolved (so to speak) the way they have.

Contrast this with the rise of modern cosmology. The theory of the Big Bang seems to me to present no less a challenge to the cosmology of Genesis, but although I have heard a few religious skeptics discount it I don't think it has nearly the same hold on the popular imagination as the debate between defenders of evolutionary theory and the proponents of intelligent design. One reason for this is the fact that modern cosmology has taken shape during a completely different historical epoch, in which that sort of science was already widely accepted among a more materialist public. If Darwin had published The Origin in 1959 instead of 1859--after the growth of molecular biology and modern genetics--I think the public attitude towards evolution would be no different than it is towards the Big Bang. There would still be a fundamentalist reaction to it, but it would be much more marginalized.

To see where the present debate will be fifty years hence I think we need only turn back to the 17th century. None of the revolutionary scientific proposals from that era, including not only Galileo's contributions to astronomy, but the theories of universal gravitation, combustion, circulation of the blood, and many others, are not exactly on the table as matters up for continued debate between working scientists and armchair theologians. No one is going before the local school board demanding that Aristotelian gravitation be taught alongside the universal theory, or that the theory of the four humors be taught alongside other medical theories. One of the principal reasons, of course, is that the theories of universal gravitation and modern medicine have far more wide-ranging practical applications than does the theory of evolution by means of natural selection. Evolutionary theory is, principally, a historical discipline; but molecular genetics and other branches of modern biology have more important applications, and so far they are robustly consistent with everything predicted by evolutionary theory. So as these science continue to impact our lives, the rabble that continues to push intelligent design will become ever more marginalized until, like the flat-earthers, they are seen for what they are.

Of course, they are already seen that way by the folks who know better, but one does wonder when the media will catch on to this fact. Part of the problem, I think, lies in the fact that too many working biologists are playing into the hands of the crazies. I teach philosophy of biology at both the undergraduate and the graduate level, and most of the textbooks that cross my desk looking for inclusion in my classroom have sections on the "debate" between evolution and intelligent design. For the life of me I can't imagine why. No philosophy of science textbook contains articles by flat-earthers who challenge the Copernican system. There aren't many such articles to begin with, I suppose, but even if there were hundreds available that would not warrant anthologizing them along with real science. The sooner we begin to treat these folks as the outliers that they are the sooner the hubbub will die down. Since publishers have to sell books, I take it that the inclusion of this stuff is still in demand. This is a good reason never to use a textbook that has such a section in it.