Tuesday, October 13, 2009

The Flaw in Richard Dawkins's "Greatest Show on Earth"

Nicholas Wade, in a nytimes book review, looks at Richard Dawkins's new book The Greatest Show on Earth: The Evidence for Evolution. Wade, while admiring much of the book, points out that Dawkins seems not to understand the difference between a "fact" and a "theory" or, worse yet, knows the difference but dogmatically refuses to acknowledge it.

Wade points out that some creationists say evolution is a fact, not a theory. But Dawkins “keeps insisting that evolution is an undeniable fact.” Wade calls us to note that we don’t speak of “the fact” of evolution, but of the "theory" of evoltuion. So – is evolution a fact or a theory? Wade says that “on this question Dawkins, to use an English expression, gets his knickers in a twist.” For example, the theory of evolution “is still in full flux, as befits any scientific theory at the forefront of research.” This being so, how can evolution be said to be a “fact?”

Wade says that Dawkins “seems to have little appreciation for the cognitive structure of science. Philosophers of science, who are the arbiters of such issues, say science consists largely of facts, laws and theories. The facts are the facts, the laws summarize the regularities in the facts, and the theories explain the laws. Evolution can fall into only one of these categories, and it’s a theory.”

Science is always changing to accommodate new knowledge. The change takes place, not in the facts, but in the theories. Theories “are sacrificed when fundamental change is needed. Ptolemaic theory yielded when astronomers found that Copernicus’s better explained the observations; Newton’s theory of gravitation turned out to be a special case of Einstein’s.” So, argues Wade, “if a theory by nature is liable to change, it cannot be considered absolutely true. A theory, however strongly you believe in it, inherently holds a small question mark. The minute you erase the question mark, you’ve got yourself a dogma.”

Dawkins, however, states that evolution “is a fact in the same sense as it is a fact that Paris is in the Northern Hemisphere.” At this point, says Wade, Dawkins has some seriously twisted knickers. He doesn’t seem to know what a theory is.

Wade argues that one can agree that evolution, which means “change,” is a historical fact. Things change, no doubt. But, in science, evolution “is the theory without which nothing in biology makes sense.” Wade writes, “The condition of this high status is that it cannot be the final and absolute truth that Dawkins imagines it to be; it is liable to future modification and change like any other scientific theory.” This, argues Wade, is the flaw in Dawkins’s reasoning. “He has let himself slip into being as dogmatic as his opponents. He has become the Savonarola of science, condemning the doubters of evolution as “history-­deniers” who are “worse than ignorant” and “deluded to the point of perversity.” This is not the language of science, or civility. Creationists insist evolution is only a theory, Dawkins that it’s only a fact. Neither claim is correct.”