PROGRESS OF SCIENCE TO 1450 A.D. 181 



mathematics, "the alphabet of all philosophy." On the other 

 hand he says : 



We must consider that words exercise the greatest influence. Al- 

 most all wonders are accomplished through speech. In words the 

 highest enthusiasm expresses itself. Therefore words, deeply thought 

 . . . keenly realized, well calculated, and spoken with emphasis, have 

 notable power. 



Bacon enunciated the essential principles of calendar reform, 

 recognizing that the current plan of 365J days led to an error 

 of one day in 130 years. He made an acute criticism of the arbi- 

 trary assumptions and the artificial complexity of the Ptolemaic 

 astronomy; he discussed reflection and refraction, spherical 

 aberration, rainbows, magnifying glasses, and shooting stars; 

 he attributed the tides to the action of the lunar rays. In a 

 chapter on geography he " comes to the conclusion that the ocean 

 between the east coast of Asia and Europe is not very broad. 

 This . . . was quoted by Columbus in 1498. ... It is pleasant 

 to think that the persecuted English monk, then two hundred 

 years in his grave, was able to lend a powerful hand in widening 

 the horizon of mankind." (See Appendix.) 



Most of this remarkable work not printed for nearly 500 

 years was so far in advance of the age that it not only failed of 

 appreciation, but exposed the author to accusations of magic, and 

 even to imprisonment. In spite of his many attainments he 

 believed in astrology, in the doctrine of " signatures " and in the 

 "philosopher's stone," and "knew" that the circle had been 

 squared. He prophesied ships propelled swiftly by mechanical 

 means and carriages without horses. He repudiated belief in witch- 

 craft, 1 and paid the penalty for his courage by many years in prison. 



DANTE ALIGHIERI (1265-1321). Another notable scholar of 

 the thirteenth century is Dante, the greatest poetical genius 

 of the Middle Ages, who requires our notice not only because of 

 his influence in awakening and stimulating the minds of his own 

 and later times, but also as the author of a treatise On Water 



1 Not merely astrology and alchemy but even magic and necromancy were at 

 this time the subjects of university lecture courses. 



