If we find the cause of such coquetry in inborn modesty which is directly opposed to the sexual impulse the question is at once asked, Of what use is this modesty? The answer which is attempted in The Play of Animals involves an essential modification of the theory of natural selection. Darwin has referred animal arts of courtship to æsthetic taste on the part of the female, who is said always to choose the handsomest and best equipped of her wooers. But it is by no means certain that such choice from a number is always the case; indeed, some observers directly contradict the theory of courtship arts at all. The Müller brothers have definitely established the fact that birds pair long before the breeding season, so that such arts can only be for the purpose of “overcoming feminine reluctance to sexual union.” And H. E. Ziegler remarks, in a notice of my book, that courtship plays are indulged in repeatedly by monogamous birds long after their permanent choice has been made. With these facts then as premises, I have reached the following conclusion: Since the sex impulse must necessarily have extraordinary strength, the interests of the preservation of species are best served by a long preliminary condition of excitement and by some checks to its discharge. The instinctive coyness of the female serves this purpose. The question is not, in my opinion, which of many males she will choose, but rather which male possesses the qualities necessary for overcoming the reluctance of the female whom he selects and besieges, and for maintaining at the same time the proper state of excitation. “The female is not then the awarder of a prize, but is rather a hunted creature; and just as the beast of prey must possess special instincts for securing his victim, so must the ardent male be equipped with special instincts for subduing the coyness of his mate.” Thus the phenomena of courtship are directly referable to a biological end, and the great importance of coyness is explained.[511] But this peculiarly feminine instinct has a salient psychological significance as well, as I have hinted in the preface to my former work: “Just as in the beast of prey instincts of ravenous pursuit are refined into the various arts of the chase, so from such crude efforts at wooing that courtship has finally developed in which sexual passion is psychologically sublimated into love.” We must suppose that the evident refinement and depth of the marriage relation among birds is largely to be ascribed to the fact that the male does not simply excite and control his mate, but seeks to win her in a less abrupt manner by the display of his charms and capabilities; and the same is true with ourselves. Without the modesty of women, which as a rule only yields to the power of love, the sexual relation would hardly be a poet’s theme, while now love is regarded as the highest flight of the human soul. “La pudeur,” says Guyau, “a civilisé l’amour.”