A HISTORY OF SCIENCE 



part of an infinite number than two, although the for- 

 mer is fifty thousand times greater than the latter. If, 

 therefore, we consider the moving bodies, we must 

 unquestionably regard the motion of the earth as a 

 much simpler process than that of the universe; if, 

 furthermore, we direct our attention to so many other 

 simplifications which may be reached only by this 

 theory, the daily movement of the earth must appear 

 much more probable than the motion of the universe 

 without the earth, for, according to Aristotle's just 

 axiom, ' Frustra fit per plura, quod potest fieri per pau- 

 ciora ' (It is vain to expend many means where a few 

 are sufficient)." 1 



The work was widely circulated, and it was received 

 with an interest which bespeaks a wide-spread un- 

 dercurrent of belief in the Copernican doctrine. Natu- 

 rally enough, it attracted immediate attention from 

 the church authorities. Galileo was summoned to ap- 

 pear at Rome to defend his conduct. The philosopher, 

 who was now in his seventieth year, pleaded age and 

 infirmity. He had no desire for personal experience of 

 the tribunal of the Inquisition; but the mandate was 

 repeated, and Galileo went to Rome. There, as every 

 one knows, he disavowed any intention to oppose the 

 teachings of Scripture, and formally renounced the 

 heretical doctrine of the earth's motion. According 

 to a tale which so long passed current that every his- 

 torian must still repeat it though no one now believes 

 it authentic, Galileo qualified his renunciation by 

 muttering to himself, " E pur si muove" (It does move, 

 none the less), as he rose to his feet and retired from 



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