354 ANTIENT METAPHYSICS, - Book V. 



Caufe adually operating iii the produdion of every new Motion, as 

 Avell as in the produdion of the lirft. 



By thefe arguments I hope to convince all the Newtonians, who 

 are fcholars and philofophers as well as geometricians and me- 

 chanics ; or, if I fliould not have that good fortune, they will at lead 

 owe me fome thanks for examining accurately, and, I hope, they 

 will think, candidly, this principle upon which Sir Ifaac has thought 

 ;proper to rear his fyftem of Aftronomy. And, if they think they 

 can give a fatisfadtory anfwer to all the arguments I have ufed a- 

 gainft it, they ought to rejoice that I have given them an opportu- 

 nity of placing Sir Ifaac's Aftronomy upon a folid foundation of 

 philofophy, which certainly has not hitherto been done. And, even 

 thofe Newtonians, who are only mathematicians and learned in 

 fads of natural hiftory, ought not to be angry that I have applied to 

 Sir Ifaac's aftronomy the principles of the philofophy of which I am 

 treating, more efpecially as he has chofen to build his Syftem up- 

 on a metaphyfical principle, which was certainly not at all necef. 

 fary ; for hp might have calculated and meafured the Motions of 

 the Celeftial Bodies, and difcovered the Laws of their Motions, with- 

 out inquiring into the Caufe af thefe Motions, or laying down fo ge- 

 neral a propofition concerning the continuation of Motion. If Euclid 

 had begun his Elements with defining and explaining what Body, 

 Quantity, and Magnitude, were, and fo had run his Science up into 

 Metaphyfics, no geometrician, however great his regard for Euclid 

 might be, could have blamed me, if, in a metaphyfical work, I had 

 iliown that the metaphyfical principles, laid down by Euclid as the 

 bafis of his geometry, were not true and folid. 



What I have here faid will, I hope, at leaft ferve for an apology 

 to all the Newtonians, whether fcholars and philofophers, or only 

 mathematicians. But, as to the pious philofopher, whofe concern is 



not 



