ASTRONOMY. 223 



principle which sustains the heavenly motions. The Deity 

 having appointed this law to matter, than which, as we 

 have said before, no law could be more simple, has turned 

 it to a wonderful account in constructing planetary systems. 



The actuating cause in these systems, is an attraction 

 which varies reciprocally as the square of the distance ; that 

 is, at double the distance, has a quarter of the force : at 

 half the distance, four times the strength ; and so on. Now, 

 concerning this law of variation, we have three things to 

 observe; first, that attraction, for any thing we know about 

 it, was just as capable of one law of variation as of another ; 

 secondly ; that, out of an infinite number of possible laws, 

 those which were admissible for the purpose of supporting 

 the heavenly motions, lay within certain narrow limits ; 

 thirdly; that of the admissible laws, or those which come 

 within the limits prescribed, the law that actually prevails 

 is the most beneficial. So far as these propositions can be 

 made out, we may be said, I think, to prove choice and 

 regulation ; choice, out of boundless variety ; and regula- 

 tion, of that which, by its own nature, was, in respect of 

 the property regulated, indifferent and indefinite. 



I. First, then, attraction, for any thing we know about 

 it, was originally indifferent to all laws of variation depend- 

 ing upon change of distance, i. e. just as susceptible of one 

 law as of another. It might have been the same at all 

 distances. It might have increased as the distance in- 

 creased. Or it might have diminished with the increase of 

 the distance, yet in ten thousand different proportions from 

 the present : It might have followed no stated law at all. 

 If attraction be, what Cotes, with many other Newtonians 

 have thought it to be, a primordial property of matter, not 

 dependent upon, or traceable to, any other material cause, 

 then, by the very nature and definition of a primordial prop- 

 erty, it stood indifferent to all laws. If it be the agency of 

 something immaterial, then also, for any thing we know 

 of it, it was indifferent to all laws. If the revolution of 

 bodies round a centre depend upon vortices, neither are 

 these limited to one law more than another. 



There is, I know, an account given of attraction, which 

 should seem, in its very cause, to assign to it the law, 

 which we find it to observe, and which, therefore, makes 

 that law, a law not of choice, but of necessity ; and it is 

 the account which ascribes attraction to an emanation from 

 the attracting body. It is probable, that the influence of such 

 an emanation will be proportioned to the spissitude of the 



