Now, can we accept the Darwinian theory, and believe that all these appendages of beauty, as well as the sexual weapons, powers of song and movement, have been developed through the preference of the females? the stronger and more ornamental males becoming in this way the parents of each successive generation. Wallace, as is well known, opposed Darwin's view, preferring to regard sexual selection as a manifestation of natural selection. He has been followed by other naturalists, who have denied this creative power of love, being unable to credit conscious choice by the females of the most gifted males. The controversy on the question has been long and at times violent. Yet, it would seem, as so often happens in all disagreements, that the difference in opinion is more apparent than founded on the facts. There is really no difficulty if once we understand the true significance of courtship. What this is I have tried to make clear. During the excitement of pairing the male birds are in a condition of the most perfect development, and possess an enormous store of superabundant vitality; this, as may readily be understood, may well express itself in brilliant colours and superfluities of ornamental plumage, as also in song, in dancing, in love tournaments and in battles. The fact that we have to remember is that the female is most easily won by the male, who, being himself most charged with sex desire--and through this means reaching the finest development--is able to create a corresponding intoxication in her, and thus, by producing in both the most perfect condition, favours the chances of reproduction. There is no need whatever to suppose any conscious choice or special aesthetic perception on the part of the females. Great effects are everywhere produced in Nature by simple causes. The female responds to the stimulus of the right male at the right moment--that is really the whole matter.[82] In these instances (brought forward in the previous section of this chapter) of the universal hunger of sex, which are fairly typical and are as complete as my space will allow, certain facts have become clear. In the first place we have seen something of the strong driving of the procreative function, which is the guarantee of the continuation and development of life. The importance of the result to be gained explains the diverse and elaborate phenomena of courtship. The higher we ascend in the animal kingdom the stronger does the sex-appetite become: it vibrates in the nerve-centres, giving rise to violent emotions which intensify all the physical and psychic activities. Love is the great creative force. It awakens impressions and desires in the individual, giving rise to what may be called "experiments in creative self-expression," to the energy of which we owe the varied and marvellous phenomena in animal life.