The author suggests that psychological trends observable in infancy constitute the basis for the whole framework of every legal system. Two main streams occur in legal systems: aggression, the application of force, as in criminal and military law; and that very considerable component of law which provides people with the resources necessary for their existence. 'Social security' measures have occurred in every period of history, intended to support members of even quite primitive cultures. The early experience of the individual is analogous to these two bases of the law, for the mother, who is the prototype for the superego, has two relationships to the child; she exists for it as a good and a bad mother, one who gives and one who punishes or deprives. But the good and giving aspect of the earliest months antedates the prohibiting and depriving aspect: Eros, not aggression, creates the first effective rules of relationship.