142 INTRODUCTORY ADDRESS 



Before this event the intellect was bound down by a scholasticism 

 which regarded knowledge as a rounded whole, the parts of which 

 were written in books and carried in the minds of learned men. The 

 student was taught from the beginning of his work to look upon 

 authority as the foundation of his beliefs. The older the authority the 

 greater the weight it carried. So effective was this teaching that it 

 seems never to have occurred to individual men that they had all the 

 opportunities ever enjoyed by Aristotle of discovering truth, with the 

 added advantage of all his knowledge to begin with. Advanced as 

 was the development of formal logic, that practical logic was wanting 

 which could see that the last of a series of authorities, every one of 

 which rested on those which preceded it, could never form a surer 

 foundation for any doctrine than that supplied by its original pro- 

 pounder. 



The result of this view of knowledge was that, although during the 

 fifteen centuries following the death of the geometer of Syracuse 

 great universities were founded at which generations of professors 

 expounded all the learning of their time, neither professor nor student 

 ever suspected what latent possibilities of good were concealed in the 

 most familiar operations of nature. Every one felt the wind blow, saw 

 water boil, and heard the thunder crash, but never thought of inves- 

 tigating the forces here at play. Up to the middle of the fifteenth 

 century the most acute observer could scarcely have seen the dawn 

 of a new era. 



In view of this state of things, it must be regarded as one of the most 

 remarkable facts in evolutionary history that four or five men, whose 

 mental constitution was either typical of the new order of things or 

 who were powerful agents in bringing it about, were all born during 

 the fifteenth century, four of them at least at so nearly the same time 

 as to be contemporaries. 



Leonardo da Vinci, whose artistic genius has charmed succeeding 

 generations, was also the first practical engineer of his time, and the 

 first man after Archimedes to make a substantial advance in develop- 

 ing the laws of motion. That the world was not prepared to make 

 use of his scientific discoveries does not detract from the significance 

 which must attach to the period of his birth. 



Shortly after him was born the great navigator whose bold spirit 

 was to make known a new world, thus giving to commercial enterprise 

 that impetus which was so powerful an agent in bringing about a 

 revolution in the thoughts of men. 



The birth of Columbus was soon followed by that of Copernicus, 

 the first after Aristarchus to demonstrate the true system of the 

 world. In him more than in any of his contemporaries do we see the 

 struggle between the old forms of thought and the new. It seems 

 almost pathetic and is certainly most suggestive of the general view 



