But so far as the theory of Darwinism is concerned it exerted a marked and rapid influence on the popular religious theory of design in nature. This is one of the oldest arguments in favour of a reasoned belief in God, and it is the one which was, and is still in one form or another, held in the greatest popular esteem. To the popular mind--and religion in a civilized country is not seriously concerned about its failing grip on the cultured intelligence so long as it keeps control of the ordinary man and woman--to the popular mind the argument from design appealed with peculiar force. Anyone is capable of admiring the wonders of nature, and in the earlier developments of popular science the marvels of plant and animal structures served only to deepen the Theist's admiration of the "divine wisdom." The examples of complexity of structure, of the interdependence of parts, and of the thousand and one cunning devices by which animal life maintains itself in the face of a hostile environment were there for all to see and admire. And when man compared these with his own conscious attempts to adapt means to ends, there seemed as strong proof here as anywhere of some scheming intelligence behind the natural process. But the strength of the case was more apparent than real. It was weakest at the very point where it should have been strongest. In the case of a human product we know the purpose and can measure the extent of its realization in the nature of the result. In the case of a natural product we have no means of knowing what the purpose was, or even if any purpose at all lies behind the product. The important element in the argument from design--that of purpose--is thus pure assumption. In the case of human productions we argue from purpose to production. In the case of a natural object we are arguing from production to an assumed purpose. The analogy breaks down just where it should be strongest and clearest.