But my ignorance of music happens to assist me with a convenient metaphor in the more controversial matter of my ignorance of science. I once made some remarks about the decline of Darwinism, in a review of the Wells “Outline of History.” This aroused rather excited criticism; but one comparatively calm critic challenged what really interests me in the matter: he said that my conundrums about the wing of the bat and similar things “could easily be solved on purely Darwinian lines by any competent zoologist, or even by one so incompetent as myself.” The conundrum in question, of course, concerns the survival value of features in their unfinished state. If a thing can fly it may survive, and if it has a wing it may fly; but if it cannot fly with half a wing, why should it survive with half a wing? Yet Darwinism pre-supposes that numberless generations could survive before one generation could fly. Now it is quite true that I am not even an incompetent zoologist; and that my critic is more competent than I, if only in the mere fact of being a zoologist at all. Nevertheless, I adhere to my opinion, and do so for a reason that seems to me worthy of some little consideration. I do it because this does happen to be exactly one of those questions on which, as it seems to me, the independent critic has really a right to check the specialist. For it is a larger question of logic, and not a smaller question of fact. It is like the difficulty of believing that a halfpenny can fall head or tail a hundred times running; which has nothing to do with the numismatic value of the coin. It is like the difficulty of believing that a mere tax could make a loaf cheaper, which has nothing to do with the agrarian craft of growing corn. There is a general tide of reason flowing against such improbabilities, even if they are possibilities; they would still be exceptions, and reason would be on the side of the rule. And whatever the details of natural history, this thing is against the very nature of things.