The bit of truth behind all this—one so eagerly denied—is that men are not gentle, friendly creatures wishing for love, who simply defend themselves if they are attacked, but that a powerful measure of desire for aggression has to be reckoned as part of their instinctual endowment. The result is that their neighbour is to them not only a possible helper or sexual object, but also a temptation to them to gratify their aggressiveness on him, to exploit his capacity for work without recompense, to use him sexually without his consent, to seize his possessions, to humiliate him, to cause him pain, to torture and to kill him. _Homo homini lupus_; who has the courage to dispute it in the face of all the evidence in his own life and in history? This aggressive cruelty usually lies in wait for some provocation, or else it steps into the service of some other purpose, the aim of which might as well have been achieved by milder measures. In circumstances that favour it, when those forces in the mind which ordinarily inhibit it cease to operate, it also manifests itself spontaneously and reveals men as savage beasts to whom the thought of sparing their own kind is alien. Anyone who calls to mind the atrocities of the early migrations, of the invasion by the Huns or by the so-called Mongols under Jenghiz Khan and Tamurlane, of the sack of Jerusalem by the pious Crusaders, even indeed the horrors of the last world-war, will have to bow his head humbly before the truth of this view of man.