THE BELFAST ADDRESS. 147 



2. 



Still earlier than these three philosophers, and 

 during the centuries between the first of them and the 

 last, the human intellect was active in other fields than 

 theirs. Pythagoras had founded a school of mathe- 

 matics, and made his experiments on the harmonic 

 intervals. The Sophists had run through their career. 

 At Athens had appeared Socrates, Plato, and Aristotle, 

 who ruined the Sophists, and whose yoke remains to 

 some extent unbroken to the present hour. Within 

 this period also the School of Alexandria was founded, 

 Euclid wrote his ' Elements ' and made some advance in 

 optics. Archimedes had propounded the theory of the 

 lever, and the principles of hydrostatics. Astronomy was 

 immensely enriched by the discoveries of Hipparchus, 

 who was followed by the historically more celebrated 

 Ptolemy. Anatomy had been made the basis of scien- 

 tific medicine ; and it is said by Draper l that vivisec- 

 tion had begun. In fact, the science of ancient Greece 

 had already cleared the world of the fantastic images 

 of divinities operating capriciously through natural 

 phenomena. It had shaken itself free from that fruitless 

 scrutiny ' by the internal light of the mind alone,' 

 which had vainly sought to transcend experience, and 

 to reach a knowledge of ultimate causes. Instead of 

 accidental observation, it had introduced observation with 

 a purpose ; instruments were, employed to aid the 

 senses ; and scientific method was rendered in a great 

 measure complete by the union of Induction and Ex- 

 periment. 



What, then, stopped its victorious advance ? Why 

 was the scientific intellect compelled, like an exhausted 



1 History of the Intellectual Development of Europe,' p. 295. 

 L 2 



