The element of truth behind all this, which people are so ready to disavow, is that [humans] are not gentle creatures who want to be loved, and who at the most can defend themselves if attacked; they are, on the contrary, creatures among whose instinctual endowments is to be reckoned a powerful share of aggressiveness. ... It is always possible to bind together a considerable number of people in love, so long as there are other people left over to receive the manifestations of their aggressiveness.