840 OUTLINES OF NATURAL PHILOSOPHY. 



in any other than the inverse ratio of the squares of 

 the distances. The expression for the force which 

 this law affords, viz. the quantity of matter, divided 

 by the square of the distance, is a line, or a magni- 

 tude of one dimension, as the expression of a force 

 must always be when reduced to the utmost simpli- 

 city. Lastly, The lines described by two bodies at- 

 tracting one another according to this law, are al- 

 ways of the second order. No other law could give 

 the same simplicity to the celestial motions, nor is it 

 likely that any one could produce the same stability. 



Gravitation, nevertheless, is not conceived by us as a 

 property essential to matter; there may be many 

 other laws equally possible, and the above considera- 

 tions point out the law actually existing, as one that 

 has been wisely selected out of an infinite number. 



Is there, then, any physical cause, yet more general, 

 into which Gravitation may be resolved; or is it an 

 ultimate fact, beyond which our knowledge cannot 

 extend ? If we look at the ill success of the attempts 

 hitherto made to explain gravitation, we shall be 

 disposed to embrace the latter opinion, and to ap- 

 ply the maxim of BACON : " Est autem ceque impe- 

 riti et leviter philosophantis in maxime unwersalibus 

 causam requirere, ac in subordinatis et subalternis 

 causam non desiderare" Nov. Org. lib. i. cap. 48. 



If, on the other hand, we consider how many different 

 laws seem to regulate the other phenomena of the 



material 



