Another point of similarity may be just alluded to. Recent discussions on the nature of play have served to bring out its utility or serviceableness. Not only is the sportive activity of children and young animals of physiological benefit as wholesome exercise, it is now seen to be valuable as a preliminary practice of actions which later on become necessary. Thus in play-combats children and young animals begin to learn the arts of skilful attack and defence.[87] Much of this benefit of play-activity is due to the circumstance that it is a mode of organised co-operation and supplies a kind of training for the serious social activity of later years. I shall hope to show later that laughter has a like value, not merely as a source of physiological benefit to the individual, but as helping us to become fit members of society. It seems hardly needful to point out that since the fact of this utility is known neither to the player nor to the laugher, it does not in the least affect the truth of our contention, that their activity is not controlled by external ends which have a practical or other serious value. {149} Our comparison justifies us in identifying play and mirth, so far as to say that when we play and when we laugh our mood is substantially the same. Common language seems to support this view. “Fun,” “frolic,” “sport,” “pastime,” these and the like may be said to cover at once all joyous play and all varieties of mirth. We are justified, therefore, in making the principle of play fundamental in our theory of laughter.[88] We may now proceed to illustrate rather more fully the presence of the play-attitude in the higher domain of laughter, the enjoyment of ludicrous spectacle.