In such manner we have constructed an ascending evolutionary series. It must not be forgotten that in such a series the highest stage is but a differentiated lower stage. It must likewise be remembered that there is a tendency for intermediate stages to leave vestigial remains wherever they developed into higher stages. We may consequently expect to find traces of “age groups” and “men’s houses” all over the world. In addition, we must remember that a number of “symptoms”—such as “the exclusion of women” from a society, the presence of “an initiation,” of “degrees,” and of “secrecy”—have always been associated with certain stages of growth. They may serve us for criteria of this growth and of the stages thereof, and they constitute proofs of historical identity. They will often appear unassociated with the definite stage assigned to them; but that is immaterial, for their almost universal presence is a sufficient guaranty of their significance. It is not necessary to inquire into their individual significance among definite societies, because a negative answer would prove nothing, as differences from the general scheme outlined can be interpreted most easily in terms of some functional change. It must of course be remembered that the various points of view from which Schurtz approached his problem were so inextricably interwoven, that it is unwarranted to assume that every position he took was as distinctly analyzed as I have attempted to show. From two points of view, a psychological and a biological one, Schurtz obtained similar conclusions. It is now only necessary, after we have seen how he established his psychological _milieu_ and his sequence of norms, to investigate the manner in which he approached the ethnological data themselves. Schurtz claims to have reached his interpretation from an inductive study of the available data. We have seen that there is good reason to suppose that he approached the data with certain preconceptions, the most important of which was the necessity of “ascending stages” in the evolution of society. He had to determine, before everything else, the initial stage of social evolution, and to look for it or for as close an approximation to it as might still be found to-day. However, as soon as we accept what Schurtz thought were the necessary consequences of the two tendencies,—of the instinct for association and of the sexual instinct,—obviously, then, that organization which conforms closest to the conditions there imposed would be the most primitive.