PROFESSOR TYXDALL'S ADDRESS. 6-^j 



During the centuries between tlie first of these three philosophers 

 and the last, the human intellect was active in other fields than theirs. 

 The Sophists had run through their career. At Athens had appeared 

 the three men, Socrates, Plato, and Aristotle, 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 he and others made some advance in optics. Archimedes had 

 propounded the theory of the lever and the principles of hydrostatics. 

 Pythagoras had made his experiments on the harmonic intervals, 

 w^hile astronomy w^as immensely enriched by the discoveries of Hippar- 

 chus, who was followed by the historically more celebrated Ptolemy. 

 Anatomy had been made the basis of scientific medicine ; and it is 

 said by Draper * that vivisection then began. 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 expe- 

 rience and reach a knowledge of ultimate causes. Instead of acciden- 

 tal observation, it had introduced observation with a purpose ; instru- 

 ments 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 neces- 

 sary 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.'' But these char- 

 acteristics must have had their causes, which lay in the circumstances 

 of the time. Rome and the other cities of the empire had fallen into 

 moral putrefaction. Christianity had appeared, offering the Gospel 

 to the poor, and, by moderation if not asceticism of life, practically 

 protesting against the profligacy of the age. The sufferings of the 

 early Christians and the extraordinary exaltation of mind which ena- 

 bled them to triumph over the diabolical tortures to which they were 

 subjected,^ must have left traces not easily effaced. They scorned 

 the earth, in view of that "building of God, that house not made with 

 hands, eternal in the heavens." The Scriptures which ministered to 

 their spiritual needs were also the measure of their science. When, 

 for example, the celebrated question of antipodes came to be discussed, 

 the Bible was with many the ultimate court of appeah Augustine, 

 who flourished a. d. 400, would not deny the rotundity of the earth, 



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



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



2 Depicted with terrible vividness in Kenan's " Antichrist." 

 Vol. v.— 42 



