Philosophy of Biology

Charles Darwin 5

There were two hypotheses. One was that there had been a lake that was now
gone. The other was that the sea had once run into the glen but no longer. After
he arrived back from the voyage, Darwin dashed up to Scotland to look at the
glen for himself. He was already predisposed to think that the sea-hypothesis was
the right one. This was the speculation in thePrinciples, and it fit right into
the theory of climate. The land in Scotland around the Great Glen had been
rising, and this meant that the sea ran out of Glen Roy. Darwin expected to find
remains of marine organisms on the tracks, but the failure to find such specimens
did not deter him. After all, if it had been a lake, where now is the barrier
that kept it in? This work resulted in Darwin’s one and only one paper in the
prestigiousPhilosophical Transactions of the Royal Society— Sedgwick was one
of the (favourable) referees, showing that the uniformitarian/catastrophist divide
was not personal — but alas it was all a massive mistake. A year or two later,
the Swiss ichthyologist Louis Agassiz (he who was later to go to Harvard and
become a bitter critic of Darwinism) visited Scotland. Used to glaciers and skilled
in studying rocks for their evidence, he immediately announced (what is true) that
the glen had held a lake, kept in place by a glacier that has since melted. Many
years later Darwin agreed that he had been wrong. The length of time that it
took for Darwin to admit his mistake was not simply a function of pride. Agassiz
was tying in his glacier work with the thesis that there had been ice ages — which
was fair enough — evidence that he took of God’s intervening powers — which
was not fair enough [Rudwick, 1974].

DARWIN BECOMES AN EVOLUTIONIST

At least not fair enough in the eyes of a Lyell or a Darwin. We move towards our
main story, Darwin and evolutionary theory. But as we do so, let us take a moment
to reflect on religion, both generally at the time and specifically in the mind of
Charles Darwin. No one but crackpots on the fringe took Genesis absolutely
literally. The Bible was true throughout but those early bits were to be understood
in a metaphorical or allegorical sense. Although there had been speculation on
the possibility of Noah’s Flood, by the time that Darwin went to Cambridge that
was denied. The catastrophists were certainly closer to a literal reading than the
uniformitarians — some thought the six days were six long periods of time, whereas
others thought there were unexplained passages of time unmentioned in Genesis
— but everyone thought the earth very old. How old, catastrophists generally
preferred not to say, on the sensible grounds that being specific could only lead to
trouble.
As an undergraduate, it seems that Darwin was really quite conservative theo-
logically. Indeed at first on theBeaglethe officers used to twit him for his literal
beliefs. But shortly after setting off, Darwin’s views started to change. He began
as a Christian theist — that is as someone who believes that God interferes in His
creation (most obviously in the Incarnation) — but evolved into a deist — that
is as someone who believes in God as unmoved mover. God set things going and