Stephanus of Byzantium has preserved a fragment of Dikæarchus, in which an explanation of the origin of the gens, phratry and tribe is suggested. It is not full enough, with respect to either, to amount to a definition; but it is valuable as a recognition of the three stages of organization in ancient Grecian society. He uses patry (patra) in the place of gens (genos), as Pindar did in a number of instances, and Homer occasionally. The passage may be rendered: "Patry is one of three forms of social union among the Greeks, according to Dikæarchus, which we call respectively, patry, phratry, and tribe. The patry comes into being when relationship, originally solitary, passes over into the second stage [the relationship of parents with children and children with parents], and derives its eponym from the oldest and chief member of the patry, as Aicidas, Pelopidas."
"But it came to be called phatria and phratria when certain ones gave their daughters to be married into another patry. For the woman who was given in marriage participated no longer in her paternal sacred rites, but was enrolled in the patry of her husband; so that for the union, formerly subsisting by affection between sisters and brothers, there was established another union based on community of religious rites, which they denominated a phratry; and so that again, while the patry took its rise in the way we have previously mentioned, from the blood relation between parents and children and children and parents, the phratry took its rise from the relationship between brothers."
"But tribe and tribesmen were so called from the coalescence into communities and nations so called, for each of the coalescing bodies was called a tribe."[251]
It will be noticed that marriage out of the gens is here recognized as a custom, and that the wife was enrolled in the gens, rather than the phratry, of her husband. Dikæarchus, who was a pupil of Aristotle, lived at a time when the gens existed chiefly as a pedigree of individuals, its powers having been transferred to new political bodies. He derived the origin of the gens from primitive times; but his statement that the phratry originated in the matrimonial practices of the gentes, while true doubtless as to the practice, is but an opinion as to the origin of the organization. Intermarriages, with common religious rites, would cement the phratric union; but a more satisfactory foundation of the phratry may be found in the common lineage of the gentes of which it was composed. It must be remembered that the gentes have a history running back through the three sub-periods of barbarism into the previous period of savagery, antedating the existence even of the Aryan and Semitic families. The phratry has been shown to have appeared among the American aborigines in the Lower Status of barbarism; while the Greeks were familiar with so much only of their former history as pertained to the Upper Status of barbarism.