52 THE REALITIES OF MODERN SCIENCE 



commentaries on Greek texts. In the spirit of the Re- 

 naissance, men went directly to the Greek manuscript 

 and acquired something of the author's passion for 

 knowledge and faith in reason. The invention about 

 1450 of the process of printing from movable type 

 enormously increased the dissemination of this knowl- 

 edge. 



By the time of the Renaissance two important in- 

 ventions of the Chinese had reached Europe. These 

 were gunpowder and the magnetic compass. With 

 the latter as a guide, Portuguese sailors had penetrated 

 into strange water and explored long stretches of the 

 African coast. They had sailed through the weedy 

 terrors of the Sargasso Sea and rounded Cape Bojador. 

 The old superstitions of a region of fire, and of gales 

 that always blew the sailor away from home (the trade 

 winds, probably), were yielding to exploration. Under 

 such conditions there came to Columbus the opinion 

 of Aristotle, that India might be reached by sailing 

 westward. 



This case of Columbus forms an interesting illus- 

 tration of the cumulative effect of knowledge. The 

 revival of learning, the growing familiarity with the 

 compass, the invention of printing, the explorations 

 of other navigators, all prepared his way. He, in 

 his turn, by his discoveries, pushed further out the 

 boundaries of human knowledge. The more persons 

 there are who know a given group of facts or theories 

 the greater is the chance that one of the many may 

 make the extension, to the possibility of which the 

 rest are blind. Knowledge is more than power ; it is 

 the condition for growth. 



