that at least a certain nucleus of direct descendants keeps alive through many generations—a rule so much more certain if it is a large place, a whole region, or even a country that we have in mind. Still we shall not hold this to be a conditio sine qua non for acknowledging the village or the city to be the same; it being in this respect much more relevant that the nucleus of the place, of the “settlement,” has endured and has preserved itself through the ages. Now, since place and region, air and climate, have a very considerable effect upon the intelligence and sentiment of the inhabitants, and seeing that a considerable change may not justly be expected with respect to this, except when the minds as well as the external conditions of the newcomers are totally different from those of the older strata, we may consider the identity of a place, in so far as it is founded upon the social connection of men with a part of the soil, as a psychological identity, and call this aspect of social life a psychological aspect. There can be no doubt that this psychological aspect is in great part dependent upon the biological aspect, and is, as a rule, closely interwoven with it. Yet it needs but little reflection to recognize that both are also to a certain extent separate and independent of each other. The subject-matter of a social psychology is different from the subject-matter of a social biology, though there exist a great many points of contact between them, and though both, apart from the foundations here given to them, may be applied to animal as well as to human societies.
II
Neither of the above-mentioned conceptions of a continuous unity or whole implies that the essential characteristic of the unity is perceived and recognized by those who belong to it, much less that it is perceived by others, by outsiders. And this is the third idea, by far the most important one for the present consideration—the idea of what I purpose to designate by the name of a corporation, including under it all social units whatever, in so far as they have this trait in common, that the mode of existence of the unity or whole itself is founded upon the consciousness of its existence, and consequently that it perpetuates itself by the conception of its reality being transmitted from one generation to
