And finally it must be pointed out that a prohibition against inbreeding as an element weakening to the race, which is imposed from practical hygienic motives, seems quite inadequate to explain the deep abhorrence which our society feels against incest. This dread of incest, as I have shown elsewhere[185], seems to be even more active and stronger among primitive races living to-day than among the civilized. In inquiring into the origin of incest dread it could be expected that here also there is the choice between possible explanations of a sociological, biological, and psychological nature in which the psychological motives might have to be considered as representative of biological forces. Still, in the end, one is compelled to subscribe to Frazer’s resigned statement, namely, that we do not know the origin of incest dread and do not even know how to guess at it. None of the solutions of the riddle thus far advanced seems satisfactory to us[186]. I must mention another attempt to explain the origin of incest dread which is of an entirely different nature from those considered up to now. It might be called an historic explanation. This attempt is associated with a hypothesis of Charles Darwin about the primal social state of man. From the habits of the higher apes Darwin concluded that man, too, lived originally in small hordes in which the jealousy of the oldest and strongest male prevented sexual promiscuity. “We may indeed conclude from what we know of the jealousy of all male quadrupeds, armed, as many of them are, with special weapons for battling with their rivals, that promiscuous intercourse in a state of nature is extremely improbable.... If we therefore look back far enough into the stream of time and judging from the social habits of man as he now exists, the most probable view is that he originally lived in small communities, each with a single wife, or if powerful with several, whom he jealously defended against all other men. Or he may not have been a social animal and yet have lived with several wives, like the gorilla; for all the natives agree that only the adult male is seen in a band; when the young male grows up a contest takes place for mastery, and the strongest, by killing and driving out the others, establishes himself as the head of the community (Dr Savage in the Boston _Journal of Natural History_, Vol. V, 1845-7). The younger males being thus driven out and wandering about would also, when at last successful in finding a partner, prevent too close breeding within the limits of the same family”[187].