SCIENCE IN THE ANCIENT WORLD 37 



But, if the fluidity of Greek religion gave one 

 advantage to philosophic thought, the very weakness 

 of that religion on the rational side gave another 

 even greater support. None but the most powerful 

 and acute of mediaeval minds could pierce the encircling 

 gloom of mediaeval Christianity, and detect the in- 

 tellectual failure of its philosophic and scientific 

 system. But any Greek philosopher at once could 

 see that the beautiful nature-myths of his national 

 faith were useless as a basis for physical speculation 

 on the origin and nature of the world. Hence, even 

 from the first, we find philosophers building on a 

 frankly rationalist theory. They differ in methods, 

 in results, but all alike gently lay aside the legendary 

 origins, reject the supernatural, and assume as an 

 axiom for the world of thought some physical 

 causation. 



Now, whatever be the truth about metaphysical 

 reality, natural science can only advance by working 

 from hand to mouth on the assumption that each 

 step is to be explained by rational and natural causes. 

 Hence the success, such as it was, of the Greek 

 philosophers. 



When the Greek states developed and outgrew 

 their earlier days, the geographical position of the 

 country, as well as its economic needs, brought them 

 into contact with the two older civilizations that we 

 have already briefly considered. Greece seems to 

 have drawn much of its philosophy, its mathematics 

 and its astronomy from Asiatic sources, while its 

 medicine and its geometry came from Egypt, possibly 

 by way of Crete. The area of Hellenic thought, the 

 product of this mingling of ideas, moved gradually 



