If it is easy to be led by sentimentalism into mistakes about what our fellow-man thinks of the question whether life is worth living, it is still easier to be misled with regard to our fellow-creatures lower in the scale. Here all is conjecture, and it is on this uncertain ground that rests the charge brought against Nature of waste and cruelty. There is the cruelty with which, in order to secure the survival of the few and fittest, the environment kills off the many who are unfit--an argument of great force, if the survivors were immortal. There is the waste of bringing into life thousands of creatures unfit, and therefore doomed to a speedy extinction. But death is the common lot; and as for waste and failure, if the short-lived creatures fulfil their purpose, they are not failures; and if their purpose is by competition to force the development of the potentially fit, then they fulfil their purpose. A man may be entered for a race for no other purpose than to force the pace. As for happiness, wild animals, to judge by their usual fit condition and by the evidence of sportsmen, do enjoy existence. But they, at any rate, have no ideals--whatever the savage may have. Yet it is conceivable that the bird that builds its nest finds some satisfaction in doing so, and that the animal that lays down her life to save her young ones has some sense of love. What is revealed as the ideal in man may be inchoately manifested as instinct in the undeveloped consciousness of the animal. If so, then the animal's life has independent value and is not merely valuable as a means to a distant future end. To sum up: science declines to take the teleological view of Nature, or to admit final causes or ends. To speak, therefore, of survival in the struggle for existence as an end, may be excellent sense, but it is unscientific: it implies an assumption of a kind about which science is agnostic. If we do, however, make this one deviation from agnosticism, we have then no difficulty in showing that evolution is a failure, for its end is survival, and we all die; and there is no compensation, or, if there is, posterity gets it, not we--an aggravation of the original injustice. If survival in the struggle for existence is the only end that we personally recognise in the conduct of our own lives, we are quite consistent in judging it to be the only end of other lives, and in condemning the Universe, for then there is neither goodness nor any wisdom in it. On the other hand, our faith in that wisdom and goodness is not genuine so long as we are prepared to stake only our arguments on it, and not our lives. XIII. EVOLUTION AS PURPOSE