404 HISTORY OF FORMAL ASTRONOMY. 



The differences of opinion respecting the Coper- 

 nican system, of which we thus see traces, led to 

 a controversy of some length and extent. This 

 controversy turned principally upon physical con- 

 siderations, which were much more distinctly dealt 

 with by Kepler, and others of the followers of 

 Copernicus, than they had been by the discoverer 

 himself. I shall, therefore, give a separate consi- 

 deration to this part of the subject. It may be 

 proper, however, in the first place, to make a few 

 observations on the progress of the doctrine, in- 

 dependently of these physical speculations. 



Sect. 2. Diffusion of the Copernican Theory. 



THE diffusion of the Copernican opinions in the 

 world did not take place rapidly at first. Indeed, 

 it was necessarily some time before the progress of 

 observation, and of theoretical mechanics, gave the 

 heliocentric doctrine that superiority in argument, 

 which now makes us wonder that men should have 

 hesitated when it was presented to them. Yet there 

 were some speculators of this kind, who were at- 

 tracted at once by the enlarged views of the uni- 

 verse which it opened to them. Among these was 

 the unfortunate Giordano Bruno of Nola, who was 

 burnt as a heretic at Rome in 1600. The heresies 

 which led to his unhappy fate were, however, not 

 his astronomical opinions, but a work which he 

 published in England, and dedicated to Sir Philip 



