I've noted this point before, and it was a point recognized by Darwin. It's the real underlying point of a commonly misunderstood passage on the eye (Origin of Species, Chapter VI):
To suppose that the eye, with all its inimitable contrivances for adjusting the focus to different distances, for admitting different amounts of light, and for the correction of spherical and chromatic aberration, could have been formed by natural selection, seems, I freely confess, absurd in the highest possible degree. Yet reason tells me, that if numerous gradations from a perfect and complex eye to one very imperfect and simple, each grade being useful to its possessor, can be shown to exist; if further, the eye does vary ever so slightly, and the variations be inherited, which is certainly the case; and if any variation or modification in the organ be ever useful to an animal under changing conditions of life, then the difficulty of believing that a perfect and complex eye could be formed by natural selection, though insuperable by our imagination, can hardly be considered real.
Darwin later goes on to say:
To arrive, however, at a just conclusion regarding the formation of the eye, with all its marvellous yet not absolutely perfect characters, it is indispensable that the reason should conquer the imagination; but I have felt the difficulty far too keenly to be surprised at others hesitating to extend the principle of natural selection to so startling a length.
It is indispensable that the reason should conquer the imagination. The imagination does indeed boggle at the things proposed by evolutionary theory, and anyone who suggests it doesn't thereby shows that they are misunderstanding evolutionary theory in the first place. This is because it is based on a sublime idea, in the technical sense. But if any particular evolutionary proposal fails, it can only be on the basis of rational arguments, and not the boggling of the imagination. This is a universe filled with imagination-boggling things. But reason is greater than imagination: mere imagination may stumble, but reason can walk through strange geometries, extraordinary vastnesses, and wildly glorious diversities.
