These analyses of the German soul are of great interest to the psychologist, the historian, and the statesmen. But, since I am compelled to select, I shall choose for description those parts of the book which are addressed to everyone, which touch us all, which are truly universal. I shall speak of the general problem of war and peace in human evolution. I shall have to resign myself to yet further sacrifices. Ignoring the chapters which discuss this topic from a historical and from a literary point of view,[49] I shall confine myself to the biological studies, for it is in these that the author's individuality finds its most original self-expression. * * * * * At grips with the hydra of war, Nicolai attacks the evil at the root. He opens with a vigorous analysis of instinct in general, for he is careful to avoid denying the innate character of war. War, he says, is an instinct which springs from the deeps of mankind, an instinct which influences even those who condemn it. It is an intoxication which is carefully fostered in time of peace; when it breaks forth, it takes possession of all alike. But because it is an instinct, it does not follow that this instinct is sacred. Rousseau has popularised the idea that instinct is always good and trustworthy. Nothing of the kind. Instinct may be mistaken. When it is mistaken, the race dies out, and we can therefore easily understand that, in races which do not die out, instinct has a valid reason for existence. Nevertheless, an animal endowed with sound instincts, may be deceived by these instincts when it leaves its primitive environment. We see an example of this in the moth which burns itself in the flame. The instinct was sound in the days when the sun was the only luminary, but no evolution has taken place to adapt this instinct to the existence of lamps. We may admit that every instinct had its use at the time when it first came into existence. This may be true of the fighting instinct, but it does not follow that the combative instinct is useful to man to-day. Instinct is extremely conservative, and survives the circumstances that produced it. For instance, the wolf, wishing to cover up its tracks, buries its excrement; the dog, a town dweller, stupidly scrapes the pavement. In the latter case instinct has become senseless, purposeless.