George Bernard Shaw in his preface to Back to Methuselah (1920):

If very few of us have read The Origin of the Species from end to end, it is not because it overtaxes our mind, but because we take in the whole case and are prepared to accept it long before we have come to the end of the innumerable instances and illustrations of which the book mainly consists. Darwin becomes tedious in the manner of a man who insists on continuing to prove his innocence after he has been acquitted. You assure him that there is not a stain on his character, and beg him to leave the court; but he will not be content with enough evidence to acquit him: he will have you listen to all the evidence that exists in the world.