In every human society of which we have any record, there are those who teach and those who learn, for learning a way of life is implicit in all human culture as we know it. But the separation of the teacher's role from the role of all adults who inducted the young into the habitual behavior of the group, was a comparatively late invention. Furthermore, when we do find explicit and defined teaching, in primitive societies we find it tied in with a sense of the rareness or the precariousness of some human tradition.