28 HISTORY OF 



systems ; that, instead of being a reasoner, he had 

 contented himself with being merely an historian. 



He begins his system by making a distinction 

 between the first part of it and the last ; the one 

 being founded only on conjecture, the other de- 

 pending entirely upon actual observation. The 

 latter part of his theory may, therefore, be true, 

 though the former should be found erroneous. 



The planets, says he, and the earth among the 

 number, might have been formerly (he only offers 

 this as conjecture) a part of the body of the sun, 

 and adherent to its substance. In this situation, 

 a comet falling in upon that great body might 

 have given it such a shock, and so shaken its 

 whole frame, that some of its particles might 

 have been driven off like streaming sparkles from 

 red-hot iron ; and each of these streams of fire, 

 small as they were in comparison of the sun, 

 might have been large enough to have made an 

 earth as great, nay many times greater, than ours. 

 So that in this manner the planets, together with 

 the globe which we inhabit, might have been 

 driven off from the body of the sun by an impul- 

 sive force : in this manner also they would con- 

 tinue to recede from it for ever, were they not 

 drawn back by its superior power of attraction j 

 and thus, by the combination of the two motions, 

 they are wheeled round in circles. 



Being in this manner detached at a distance 

 from the body of the sun, the planets, from hav- 

 ing been at first globes of liquid fire, gradually 

 became cool. The earth also having been im- 

 pelled obliquely forward, received a rotatory 



