A reference to the best known of William Paley's (1743-1805) arguments for the existence of God. A watch is too complicated, and too functional, to have come about by accident: it carries its own evidence of having been purposefully designed. The argument seems to apply a fortiori to a living body, which is even more complicated than a watch. Darwin, as a young man, was deeply impressed by this. Although he later destroyed the God part of the argument, by showing that natural selection can play the role of watchmaker to living bodies, he did not destroy the fundamental point ΓÇö still under-appreciated ΓÇö that complicated design demands a very special kind of explanation. God apart, the natural selection of small inherited variations is probably the only agency capabale of doing the job.