PREFACE. 



Ill 



their thoughts upon the nobleft fubjeds that can fill the mind of man, 

 I have given them to the public, hoping that every one, who takes the 

 trouble to read them, will at leaft be convinced, that the philofophers 

 of antiquity have not beflowed fo much time and labour upon thefe 

 high fubjeds to no purpofe. 



The authors I have chiefly followed are, Plato and Arlftotle, toge- 

 ther with the later philofophers of the Alexandrian School, fuch as, 

 Plotinus, Porphyry, Jamblichus, Ammonius Hermeias, and his fcho- 

 lars, Simplicius and Johannes Philoponus, the two bed commentators 

 upon Ariftotle ; likewife Proclus, who was thought to underftand the 

 philofophy of Plato fo well, that he was dignified with the title of his 

 fuccejfor. As the writings of thefe later philofophers are very rare, and 

 themlelves but little known, I propofe, in a future volume, (if I live 

 to publifh another), to give fome account of them, and, at the fame 

 time, a Ihort hiftory of this philofophy. 



I fhould think myfelf ungrateful, if I did not acknowledge my obli- 

 gations to one modern author, of whom I have made much ufe. It 

 is-Dr Cudworth, author of ' The true intelleftual Syflcm of the 

 * Uni'verfe.^ Ke is more learned in the whole antient philofophy, the 

 older as well as the later, than any modern author I know : And the 

 ftyle in which he writes is copious and learned, very different from 

 the fafliionable llyle of this age. The book is at prefent little 

 known, and hardly read by any body. Before it fell into my hands, 

 I had formed my fyftem, which 1 was exceedingly pleafed to find a- 

 grecd fo well with the Doctor's. And, indeed, it is no wonder that 

 it {liould, confidering that they are both drawn from the fame 

 fources. I was particularly pleafed that he agreed with me in what I 

 have laid down as a fundamental principle, that body cannot move it- 

 felf, and, therefore, what moves body mud be incorporeal *. He 



a 2 has 



* Cudworth, page 888. 



