48 THE HISTORY OF SCIENCE 



of the gospel. One of the ablest of the Church Fa- 

 thers regretted his early education and said that it 

 would have been better for him if he had never heard of 

 Democritus. The Christian writer Lactantius asked 

 shrewdly whence atoms came, and what proof there 

 was of their existence. He also allowed himself to 

 ridicule the idea of the antipodes, a topsy-turvy 

 world of unimaginable disorder. In 389 A.D. one of 

 the libraries at Alexandria was destroyed and its 

 books were pillaged by the Christians. In 415 

 Hypatia, Greek philosopher and mathematician, was 

 murdered by a Christian mob. In 642 the Arabs 

 having pushed their conquest into northern Africa 

 gained possession of Alexandria. The cause of learn- 

 ing seemed finally and irrecoverably lost. 



The Arab conquerors, however, showed themselves 

 singularly hospitable to the culture of the nations 

 over which they had gained control. Since the time 

 of Alexander there had been many Greek settlers in 

 the larger cities of Syria and Persia, and here learn- 

 ing had been maintained in the schools of the Jews 

 and of a sect of Christians (Nestorians), who were 

 particularly active as educators from the fifth century 

 to the eleventh. The principal Greek works on sci- 

 ence had been translated into Syrian. Hindu arith- 

 metic and astronomy had found their way into Persia. 

 By the ninth century all these sources of scientific 

 knowledge had been appropriated by the Arabs. 

 Some fanatics among them, to be sure, held that 

 one book, the Koran, was of itself sufficient to in- 

 sure the well-being of the whole human race, but 

 happily a more enlightened view prevailed. 



In the time of Harun Al-Rashid (800 A.D.), and 



