When, under the impulse of the surprise occasioned by the irregularities observed in the course of phenomena, men had once peopled the world with supernatural beings,[567] they felt the need of making agreements with these redoubtable forces with which they had surrounded themselves. They understood that the best way to escape being overwhelmed by them was to ally themselves to some of them, and thus make sure of their aid. But at this period of history men knew no other form of alliance and association than the one resulting from kinship. All the members of a single clan aid each other mutually because they are kindred or, as amounts to the same thing, because they think they are; on the other hand, different clans treat each other as enemies because they are of different blood. So the only way of assuring themselves of the support of these supernatural beings was to adopt them as kindred and to be adopted by them in the same quality: the well-known processes of the blood-covenant permitted them to attain this result quite easily. But since at this period, the individual did not yet have a real personality, and was regarded only as a part of his group, or clan, it was the clan as a whole, and not the individual, which collectively contracted this relationship. For the same reason, it was contracted, not with a particular object, but with the natural group or species of which this object was a part; for men think of the world as they think of themselves, and just as they could not conceive themselves apart from their clans, so they were unable to conceive of anything else as distinct from the species to which it belonged. Now a species of things united to a clan by a bond of kinship is, says Jevons, a totem.