466 ON THE ORIGIN OF FORCE. 



justified, when arguing against it, in assuming all the 

 results of those laws as established truths : they being, 

 in effect, the very things which the hypothesis is framed 

 to account for. The law in question, constituted as the 

 material universe is, is absolute and universal : and no 

 view of matter and motion can be a true one which is 

 incompatible with it. 



(8.) The inward pressure of an etherial medium sur- 

 rounding the sun upon the earth and planets, suggested 

 by Newton as a mode of escape from the metaphysical 

 difficulty of attraction at a distance, is either only another 

 form of the collision theory above combated, or an 

 evasion of the difficulty by substituting repulsive for 

 attractive force. If the ether press by its elasticity, be- 

 sides supposing its particles endowed with the neces- 

 sary amount of repulsion ; what, it must be asked, but a 

 repulsion emanating from the sun (and thereby equilibrat- 

 ing and rendering ineffective its inward pressure) is to 

 keep it from rushing in on all sides, and destroying that 

 inequality of density on which its supposed inward pres- 

 sure depends 1 If not, its agency must be simply that 

 of an inert resisting medium, rendering the continued 

 revolution of the planets round the sun impossible, and 

 causing them, while it lasts, to rotate on their axes in a 

 direction contrary tj that of their orbital m tion, as a direct 

 consequence of the more rapid abstraction of motion 

 from their outer than from their inner hemispheres. The 

 hypothesis of Le Sage which assumes that every point of 

 space is penetrated at every instant of time by material 

 particles, sui generis, moving in right lines in every possible 



