There is no other creationist argument (if you discount falsehoods like ‘‘There aren’t any intermediate fossils’’ and ignorant absurdities like ‘‘Evolution violates the second law of thermodynamics’’). However superficially different they may appear, under the surface the deep structure of creationist advocacy is always the same. Something in nature—an eye, a biochemical pathway, or a cosmic constant—is too improbable to have come about by chance. Therefore it must have been designed
Darwinian natural selection, which, contrary to a deplorably widespread misconception, is the very antithesis of a chance process, is the only known mechanism that is ultimately capable of generating improbable complexity out of simplicity.
‘‘Irreducible complexity’’ is nothing more than the familiar ‘‘What is the use of half an eye?’’ argument, even if it is now applied at the biochemical or the cellular level. And ‘‘specified complexity’’ just takes care of the point that any old haphazard pattern is as improbable as any other, with hindsight. A heap of detached watch parts tossed in a box is, with hindsight, as improbable as a fully functioning, genuinely complicated watch. As I put it in The Blind Watchmaker, ‘‘complicated things have some quality, specifiable in advance, that is highly unlikely to have been acquired by random chance alone. In the case of living things, the quality that is specified in advance is, in some sense, ‘proficiency’; either proficiency in a particular ability such as flying, as an aero-engineer might admire it; or proficiency in something more general, such as the ability to stave off death....’
It is obviously futile to try to explain it simply by specifying even greater complexity. Darwinism really does explain it in terms of something simpler—which in turn is explained in terms of something simpler still and so on back to primeval simplicity. Design may be the temporarily correct explanation for some particular manifestation of specified complexity such as a car or a washing machine (prior probability)
So all those calculations with which creationists love to browbeat their naı ¨ve audiences—the mega-astronomical odds against an entity spontaneously coming into existence by chance—are actually exercises in eloquently shooting themselves in the foot. It leaps straight from the difficulty—‘‘I can’t see any solution to the problem’’—to the cop-out—‘‘Therefore a Higher Power must have done it.’’