DESCRIPTIO GLOBI INTELLECTUALIS. 273 



However this difficulty is got over, you will at any 

 rate nut venture to confound Hesperus and the morning 

 star. It is true that one of the great teachers of Greece 

 long since asserted that they are the same ; but the 

 speculative fancies of Pythagoras must be rejected not 

 than those of Ptolemy or Regiomontanus. 



We find that Bacon, both in the De Augmentis and 

 in the following tract, speaks of the constructions of 

 astronomy as purely hypothetical. In this he agrees 

 with many other writers. It was a common opinion 

 that these constructions had no foundation in reality, 

 but were merely employed as the basis of mathematical 

 calculations. They served to represent the phenomena, 

 and that was all. This view, which has not been with- 

 out influence on the history of astronomy, inasmuch as 

 it made the transition from one hypothesis to another 

 more easy than it would have been if either had been 

 stated as of absolute truth, connected itself with a cir- 

 cumstance not unfrequently overlooked. The struggle 

 between the peripatetic philosophers and the followers 

 of Copernicus has caused an earlier struggle of the same 

 kind to be forgotten. The Ptolemaic system is in real- 

 ity not much more in accordance with the philosophy 

 of Aristotle than the Copernican ; and therefore, while 

 the authority of Aristotle was unshaken, it could only 

 be accepted, if accepted at all, as a means of represent- 

 ing the phenomena. The motions of the several orbs 

 of heaven must, if our astronomy is to accord with 

 Aristutle, be absolutely simple and concentric. On 

 these conditions only can the incorruptibility of the 

 heavens be secured. Consequently eccentrics and epi- 

 cycles must be altogether rejected ; and as the Ptole- 

 maic system necessarily employs them, it follows that 



VOL. VII. 18 



