CH. v. CONCLUDING REMARKS. 35 



read in Grecian history how Greece and the Greek colonies 

 were conquered by the Romans more than a hundred years 

 before Christ was born; and when the Greeks ceased to be a 

 free people they gradually lost their love of discovery and 

 of science. The school at Alexandria continued to be 

 famous for many centuries after Christ, but the professors 

 who taught there only repeated the sayings of Ptolemy, 

 Aristotle, Galen, and the other great discoverers, and did 

 not find out new facts for themselves ; and at last, in the year 

 640 after Christ, the Arabs took possession of the city, and 

 it soon ceased altogether to be Greek. 



You must remember that in these five chapters we have 

 only been able to speak of some of the greatest men, and 

 then only of a few of the discoveries they made. You will 

 hear of many celebrated Greek philosophers, as, for example, 

 Socrates and Plato, whose names are not mentioned here be- 

 cause they wrote on subjects such as the mind and the soul, 

 which belong to higher philosophy, and not to Natural 

 Science. You will also hear of many strange and absurd 

 notions about the causes of things which in those early 

 days were held, even by such men as Pythagoras or Galen ; 

 but in this book we have only to try to understand the real 

 facts which have been discovered ; and there is no doubt 

 that the Greeks, by a patient study of nature, and by making 

 real and careful observations and experiments, laid the 

 foundation of much of the knowledge which we have carried 

 so much further in modern times. The moment they began 

 merely to repeat the teachings of others, instead of trying 

 and proving the truth of them, they made no more disco- 

 veries, but lost a great deal they had gained. For a mere 

 reading of books will not teach science ; and if you admire 

 these men for making great discoveries, and would like to 



