So in the case of organs, we believe that "organs have been formed so that their possessors may compete successfully with other beings and thus increase their number."[1] We fearlessly then ask, in reference to each part, What is its use? And if it is of no present use, we do not say, "The Creator put it there for symmetry, or as part of a plan," but we ask. What meaning has it had in the past? How can we relate it with by-gone if not with existing conditions? If ontogeny, the history of the individual, gives us no answer, we fall back upon phylogeny, the history of the race. Organs, which on the old theory of special creations were useless and meaningless, are now seen to have their explanation in the past or in the future, according as they are rudimentary or nascent. There is nothing useless, nothing meaningless in Nature, nothing due to caprice or chance, nothing irrational or without a cause, nothing outside the reign of law. This belief in the universality of law and order is the scientific analogue of the Christian's belief in Providence. And, as Prof. Huxley admits, it is an "act of faith," brought to Nature, and slowly, and as yet only in part, verified in Nature. Yet to doubt that Nature is everywhere rational, and therefore intelligible, would be for a scientific man an act of intellectual suicide.
But if we believe in law and order everywhere in Nature, though there is so much which is as yet hopelessly irreducible to law, and if that belief is read into Nature long before we can read it in Nature, may we not approach the moral difficulty in the same spirit? For there is here a curious parallel. What our rational nature resents is not the existence of facts which we can not explain, but of facts which have no explanation; and what the moral nature rebels at is not suffering and pain, but needless—i. e., meaningless—pain, suffering which might have been avoided. And here Darwinism gives us a hint, if it is but a hint: "Natural selection works solely by and for the good of each being."[2] The arrangement of the world is "generally beneficent,"[3] and "tends to progress toward perfection." But then—
It is no final solution of the difficulty, and yet man, who is so wise and good that he is always saying with King Alphonso of Castile, "If God had called me to his councils things would have been in better order," has invented competitive examinations,
