36 MARRIAGE AND HEREDITY 



In polygamous and licentious communities the 

 sensual appetites of men are ministered to by the 

 transference of women from one master to another, 

 but this custom is counteracted by the impulse of the 

 mother to cling to the father of her child, and by the 

 repugnance of men themselves to promiscuous families. 

 The family instincts may of course be overruled, as 

 they were in Eome, where, in the time of Augustus, 

 it was thought expedient to pass enactments against 

 celibacy and to offer special privileges to the fathers 

 of three children. But the race that persistently 

 disregards Nature's laws incurs the penalty of decay 

 and extinction. It rarely happens that this drastic 

 remedy is carried out to the full, as it appears to have 

 been in the case of the Athenian civilisation. In the 

 most abandoned communities there are never wanting 

 philosophers and fanatics to plead for asceticism or 

 moderation. Plato and Pythagoras preached in vain to 

 the Greeks, but they exercised an important influence 

 in the world by paving the way for the regenerative 

 doctrines of Christianity. Other causes operated in 

 the same direction. We have seen how Usus grew up 

 in Eome as a corrective to the highly artificial and 

 pernicious system of political marriage. Voluntary 

 unions imply a certain freedom of choice on the part 



