The Theory of Sexual Selection. 405 



how, out of such a feeling as a cause, the beauty of 

 organic nature may have followed as an effect. 



Now we have already seen how the theory of sexual 

 selection su[)poses this to have happened. But 

 against this theory a formidable objection arises, and 

 one which I have thought it best to reserve for treat- 

 ment in this place, because it serves to show the 

 principal difference between Mr. Darwin's two great 

 generalizations, considered as generalizations in the 

 way of mechanical theory. For while the theory of 

 natural selection extends equally throughout the whole 

 range of organic nature, the theory of sexual selection 

 has but a comparatively restricted scope, which, more- 

 over, is but vaguely defined. For it is obvious that 

 the theory can only apply to living organisms which 

 are sufficiently intelligent to admit of our reasonably 

 accrediting them with aesthetic taste — namely, in 

 effect, the higher animals. And just as this con- 

 sideration greatly restricts the possible scope of the 

 theory, as compared with that of natural selection, so 

 does it render undefined the zoological limits within 

 which it can be reasonably employed. Lastly, this 

 necessarily undefined, and yet most important limita- 

 tion exposes the theory to the objection just alluded 

 to, and which I shall now mention. 



The theory, as we have just seen, is necessarily 

 restricted in its application to the higher animals. 

 Yet the facts which it is designed to explain are not 

 thus restricted. For beauty is by no means restricted 

 to the higher animals. The whole of the vegetable 

 world, and the whole of the animal world at least as 

 high up in the scale as the insects, must be taken as 

 incapable of aesthetic feeling. Therefore, the extreme 



