The Ear without the Eye

Were there no example in the world of contrivance except that of the eye, it would be alone sufficient to support the conclusion, which we draw from it, as to the necessity of an intelligent Creator. . . . The proof is not a conclusion that lies at the end of a chain of reasoning, of which chain each instance of contrivance is only a link, and of which, if one link fail, the whole fails; but it is an argument separately supplied by every separate example. An error in stating an example affects only that example. The argument is cumulative in the fullest sense of that term. The eye proves it without the ear; the ear without the eye. The proof in each example is complete; for when the design of the part and the conduciveness of its structure to that design is shown, the mind may set itself at rest; no further consideration can detract anything from the force of the example.