THE BELFAST ADDRESS. 451 



Lucretius, which forms the basis of Mr. Tennyson's noble 

 poem, is in strict accordance with his philosophy, which 

 was severe and pure. 



SECTION 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 mathematics, 

 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 pro- 

 pounded the theory of the lever, and the principles of 

 hydrostatics. Astronomy was immensely enriched by the 

 discoveries of Hipparchus, who was followed by the his- 

 torically more celebrated Ptolemy. Anatomy had been 

 made the basis of scientific medicine; and it is said by 

 Draper* that vivisection 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 obser- 

 vation 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 

 Experiment. 



What, then, stopped its victorious advance? Why was 

 the scientific intellect compelled, like an exhausted soil, to 

 lie fallow for nearly two millenniums, before it could 

 regather the elements necessary to its fertility and strength? 

 Bacon has already let us know one cause; Whewell ascribes 

 this stationary period to four causes obscurity of thought, 

 servility, intolerance of disposition, enthusiasm of temper; 

 and he gives striking examples of each.f But these char- 



* " History of the Intellectual Development of Europe," p. 295. 

 f " History of the Inductive Sciences," vol. i. 



