the classificatory system as a whole has been determined by its origin in a specific form of social organisation. I propose now to leave the classificatory system for a moment and inquire whether another system of denoting and classifying relationships may not similarly be shown to be determined by social conditions. The system I shall consider is our own. Let us examine this system in its relation to the form of social organisation prevalent among ourselves.
Just as among most peoples of rude culture the clan or other exogamous group is the essential unit of social organisation, so among ourselves this social unit is the family, using this term for the group consisting of a man, his wife, and their children. If we examine our terms of relationship, we find that those applied to individual persons and those used in a narrow and well-defined sense are just those in which the family is intimately concerned. The terms father, mother, husband and wife, brother and sister, are limited to members of the family of the speaker, and the terms father-, mother-, brother-, and sister-in-law to the members of the family of the wife or husband in the same narrowly restricted sense. Similarly, the terms grandfather and grandmother are limited to the parents of the father and mother, while the terms grandson and granddaughter are only used of the families of the children in the narrow sense. The terms uncle and aunt, nephew and niece, are used in a less restricted sense, but even these
