5IO DISSERTATION ON 



ftudied ; the philofophy, I mean, is metaphyfics, and the philofophy 

 of Mind ; for, by mathematics, after having discovered, from obfer- 

 vation, certain phaenomena concerning the motion of bodies, we can 

 inveftigate theorems concerning the velocity and force with which 

 they are moved, the fpaces they pafs through, and their pofitions 

 with refpedt to one another. But the queflion here is concerning the 

 principle of motion in thefe bodies — "What is the moving power ? — 

 and in what manner that power operates fo as to produce the motion? 

 — 1 hefe are queftions, in which geometry, mechanics, or calculation, 

 can be of no ufe. Whether a genius like Sir Ifaac's, that excelled fo 

 much in lines and figures, could have made the fame proficiency in 

 the ftudy of Mind, and of the firft philofophy, is what I will not pre- 

 tend to determine ; but this, I think, I know very certainly, that, 

 however great Sir Ifaac^s genius was, even for metaphyfics, he could 

 not underftand it, without having ftudied it. And this, farther, I 

 think, I know alfo, with great certainty, that, let a man be e- 

 ver fo great a geometer, yet, if he be not learned in the firft philo- 

 fophy, he cannot underftand even the principles of his own fcience. 



The firft thing to be confidered in this inquiry, is the moving 

 power. Every body that is moved, (and nothing but body can be 

 properly faid to be moved *), is moved either by fome other body, or 

 by Mind ; I mean by body immediately ; for, according to my philo- 

 fophy. Mind is ultimately the only moving power in the univerfe. 

 When body moves body, the body moving muft neceflarily be in con- 

 tadl, either mediately or immediately, with the body moved ; for I 

 hold, that fucli of the Newtonians, that fpeak of bodies at a diftance 

 attrading one another, fpeak without having an idea of what they 

 fay, unlefs they can ftiow that there is fome medium betwixt the bo- 

 dies, by v^'hich they can operate upon one another. An attraction, 



. there- 



* See this demonftrated, page 286. 



