Where the matriarchate prevails we naturally find no prejudice against marriage with a half-sister on the father’s side, while union with a uterine sister is incestuous.  Sara was a half-sister of Abraham on the father’s side, and Tamar could have married her half-brother Amnon,[114] though they were both children of David; and a similar condition prevailed in Athens under the laws of Solon.[115] Herodotus says of the Lycians: 

Ask a Lycian who he is, and he will answer by giving his own name, that of his mother, and so on in the female line.  Moreover, if a free woman marry a man who is a slave, their children are free citizens; but if a free man marry a foreign woman, or cohabit with a concubine, even though he be the first person in the state, the children forfeit all rights of citizenship.[116]

Herodotus also relates that when Darius gave to the wife of Intaphernes permission to claim the life of a single man of her kindred, she chose her brother, saying that both husband and children could be replaced.[117] The declaration of Antigone in Sophocles,[118] that she would have performed for neither husband nor children the toil which she undertook for Polynices, against the will of the citizens, indicates that the tie of a common womb was stronger than the social tie of marriage.  The extraordinary honor, privilege, and proprietary rights enjoyed by ancient Egyptian and Babylonian wives[119] are traceable to an earlier maternal organization.

All ethnologists admit that descent through females has been very widespread, but some deny that this system has been universally prevalent at any stage of culture.  Those who have diminished its importance, however, have done so chiefly in reinforcement of their denials of the theory of promiscuity.  It has been very generally assumed that maternal descent is due solely to uncertainty of paternity, and that an admission that the maternal system has been universal is practically an admission of promiscuity.  Opponents of this theory have consequently felt called upon to minimize the importance of maternal descent.[120] But descent through females is not, in fact, fully explained by uncertainty of parentage on the male side.  It is due to the larger social fact, including this biological one, that the bond between mother and child is the closest in nature, and that the group grew up about the more stationary female; and consequently the questions of maternal descent and promiscuity are by no means so inseparable as has commonly been assumed.  We may accept Sir Henry Maine’s terse remark that “paternity is a matter of inference, as opposed to maternity, which is a matter of observation,"[121] without concluding that society would have been first of all patriarchal in organization, even if paternity had been also a matter of observation.  For the association of the woman with the child is immediate and perforce, but the immediate interest of the man is in the woman, through the power of her sexual attractiveness, and his interest in the child is secondary and mediated through her.  This relation being a constant one, having its roots in the nature of sex rather than in the uncertainty of parentage, we may safely conclude that the so-called “mother-right” has everywhere preceded “father-right,” and was the fund from which the latter was evolved.