306 THE PRINCIPLES OF HEREDITY 



doubt due to the influx of aliens ; not, however, because the 

 aliens brought an infusion of inferior blood, but solely 

 because their presence resulted in a change for the worse in 

 the mental training of the youth. The scanty scientific 

 knowledge of the time left the great Pagans, as in the case 

 of ignorant people at the present day, susceptible to the 

 influence of superstition. With the aliens from the East 

 came a multitude of creeds of which the most conspicuous 

 features were mystery not explanation, superstition not 

 reason and clear thought ; creeds that had associated with 

 them, therefore, a system of mental training that left the 

 mind cribbed, cabined, and confined, walled about by beliefs 

 held as unintelligent prejudices. This process of mental 

 degradation may be clearly traced in the history of the 

 declining Greeks. It may be traced even more clearly in 

 the latter pages of Roman history, for here we have very 

 copious evidence. It began, in the latter case, before the 

 advent of the Christians with the worship of the Egyptian 

 deities Isis and Serapis, and the wide spread of other mystic 

 religions. But it cannot be doubted that the form taken by 

 early Christianity, the mental atmosphere in which it trained 

 the youth, was largely responsible for the downfall of the 

 highest civilization the world had yet seen. 



484. " The energies of Christendom were diverted from all 

 useful and progressive studies, and were wholly expended on 

 theological disquisitions. A crowd of superstitions attributed 

 to infallible wisdom, barred the path of knowledge, and the 

 charge of magic, or the charge of heresy, crushed every bold 

 inquiry in the sphere of physical nature or of opinions. 

 Above all, the conditions of true inquiry had been crushed 

 by the Church. A blind, unquestioning credulity was in- 

 culcated as the first of duties, and the habit of doubt, the 

 impartiality of a suspended judgment, the desire to hear both 

 sides of a disputed question, and to emancipate the judgment 



regarded with honour and admiration. The religious theory of Pagan- 

 ism had in this respect some influence. It was eminently poetical, 

 eminently patriotic, and eminently tolerant . . . the notion of many 

 distinct groups of gods led men to tolerate many forms of worship and 

 great varieties of creeds. In that colossal amalgam of nations of which 

 Rome became the metropolis, intellectual liberty still further advanced ; 

 the vast variety of philosophies and beliefs expatiated unmolested ; the 

 search for truth was regarded as an important element of virtue, and 

 the relentless and most sceptical criticism which Socrates had applied 

 in turn to all the fundamental propositions of popular belief remained 

 as an example to his successors." (Lecky, History of European Morals, 

 vol. ii., pp. 189-90.) 



