THE WORLD MACHINE 



admirable a symmetry of the universe and so harmonious a 

 connection of orbits as by placing the lamp of the world, the 

 sun, in the midst of the beautiful temple of nature as on a 

 kingly throne, with the whole family of circling stars revolving 

 around him." 



It is the mediocre imagery of a simple priest. For the rest, 

 he speculates little : he is content to describe ; he does not 

 guess. His mind was that of a geometer. He does not try 

 to seek out causes which lie at the base of this wonderful scheme 

 whose secret he has at last penetrated. The force which moves 

 the planets, which so tormented the mind of Kepler, did not 

 trouble his. Some attempt has been made, by Humboldt among 

 others, to show that some crude notions he had of the force of 

 gravitation. There is a passage with these rather striking 

 lines : 



"The earth cannot be regarded as the middle point of all 

 these planetary motions ; that is apparent from the unequal 

 and variable movements of the planets themselves, and from 

 their varying distance from the earth, which cannot be explained 

 by means of concentric circles with the earth as a common 

 centre. Inasmuch, now, in this view, several middle points 

 would necessarily exist, so no one can be in doubt as to whether 

 this middle point of the world be that of terrestrial gravity, or 

 elsewhere. I at least hold to the view that gravity is nothing 

 else than a natural inborn endeavour impressed upon every 

 particle by the divine providence of the Master of the universe, 

 whereby these particles tend to coalesce into the shape of a 

 sphere, and thus gain their unity and wholeness. And it is 

 to be supposed that this inclination or tendency dwells also in 

 the sun, the moon, and the other planets, and it is to this cause 

 that the spherical form in which they appear is due, while they 

 nevertheless in varied fashion cruise about their orbits." l 



The passage is interesting as a curiosity ; it is evident enough 

 from many another that the idea of the sun as an attractive 

 centre was wholly foreign to his thought. He does not seem 

 to have been interested in the speculations of the ancients. The 

 ideas of Anaxagoras he does not mention ; neither those of 

 Simplicius. There is nothing in the mental habit of the time 

 to impel him to think upon such matters at all. Machines, 

 mechanical arrangements of any sort, were almost wholly lack- 

 1 De Revolutionibus, Book I. chap. ix. 



