calls him, Nicolaus Copernicus, as scholars call him, was born in 1473       
at Thorn (Torun) on the Vistula in West Prussia, which, seven years          
before, had been ceded to Poland by the Teutonic Knights; he was a           
Prussian in space, a Pole in time. His mother came of a prosperous                     
Prussian family; his father hailed from Cracow, settled in Thorn,            
and dealt in copper. When the father died (1483), the mother's               
brother, Lucas Watzelrode, Prince Bishop of Ermland, took charge of          
the children. Nicolaus was sent at eighteen to the University of             
Cracow to prepare for the priesthood. Not liking the Scholasticism           
that had there suppressed humanism, he persuaded his uncle to let            
him study in Italy. The uncle had him appointed a canon of the               
cathedral at Frauenburg in Polish East Prussia, and gave him leave           
of absence for three years. *06069                                           
  At the University of Bologna (1497-1500) Copernicus studied                
mathematics, physics, and astronomy. One of his teachers, Domenico           
de Novara, once a pupil of Regiomontanus, criticized the Ptolemaic                     
system as absurdly complex, and introduced his students to ancient           
Greek astronomers who had questioned the immobility and central              
position of the earth. Philolaus the Pythagorean, in the fifth century       
before Christ, had held that the earth and the other planets moved           
around Hestia, a central fire invisible to us because all known              
parts of the earth are turned away from it. Cicero quoted Hicetas of         
Syracuse, also of the fifth century before Christ, as believing that         
the sun, the moon, and the stars stood still, and that their                 
apparent motion was due to the axial rotation of the earth. Archimedes       
and Plutarch reported that Aristarchus of Samos (310-230 B.C.) had           
suggested the revolution of the earth around the sun, had been accused       
of impiety, and had withdrawn the suggestion. According to Plutarch,         
Seleucus of Babylonia had revived the idea in the second century             
before Christ. This heliocentric view might have triumphed in                
antiquity had not Claudius Ptolemy of Alexandria, in the second              
century of our era, restated the geocentric theory with such force and             
learning that hardly anyone thereafter dared to challenge it.                
Ptolemy himself had ruled that in seeking to explain phenomena,              
science should adopt the simplest possible hypothesis consistent             
with accepted observations. Yet Ptolemy, like Hipparchus before him,                 
to explain the apparent motion of the planets, had been compelled by