Geology 



selves and by others. Only too frequently then, as now, 

 however, the victory in these disputations was to the 

 man of many words rather than to him of sound obser- 

 vation and deduction. 



Accordingly we find that while some of the Greek 

 writers founded their views on observation, perhaps 

 slightly tinted by mythical ideas, others simply followed 

 the older ideas without troubling to seek observational 

 confirmation of them. 



As examples from this period we may take Pythagoras 

 (580 B.C.) and Aristotle (384-322 B.C.). 



The former believed that changes had taken place 

 in the relative positions of land and sea, that the valleys 

 were the result of the denudation of the solid land 

 by the agencies of streams and rivers, and many 

 other things which are now accepted as geological 

 facts. 



" Nothing perishes in the world, but things change 

 their form. To be born means simply that a thing 

 begins to be something different from what it was before, 

 and dying is ceasing to be the same thing." 



Here we have a foreshadowing of the modern doctrine 

 of the indestructibility of matter. 



Aristotle, who by his researches in natural history 

 and his profound reasoning powers was venerated 

 throughout the Middle Ages as the creator of all the 

 sciences, seems on the other hand to have followed 

 the older myths as regards cosmogony, and to have 

 believed in a succession of inundations alternated with 

 conflagrations. 



After the introduction of Christianity a long period 

 elapsed during which little advance was made in the 



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