Chap. VI. ANTIENT METAPHYSICS. 405 



CHAP. VI. 



Proved in the preceding Chapters^ that Mind is the oidy Catife ^Motiori 

 in the Heavens. — Mind very properly typified by Fire. — Proved alfo^- 

 that the Motion of the Celejlial Bodies is not compounded but 

 fimple. — The Purpofe of this Chapter tofjow that Sir Ilaac'j- Syficm 

 of Aftronomy can be fupported ivithout arbitrary or impoffible Sup- 

 pofitions. — Prejudice removed that may arife from the Author s not 

 being learned in Geometry or Mechanics. — No inferior Science demon- 

 firatcs its own Principles. — Thefe to be found only in Metaphyfics, 

 or the Firft Philofophy. — EuclidV Geometry an Example of this. — 

 The fame is true of Sir Ilaac NewtonV Aflronomy. — The- Laws of 

 the Planetary Motion difcovered by Sir Ifaac Newton. — Before him 

 Aflronomy no Science, but only a ColleElion of Fads. — A curious 

 Fa£i difcovered by Kepler, concerning the Proportions betivixt the Pe- 

 riods and Diftances of the Planets. — This he knew only as a Fact ; 

 but Sir Ifaac has made a Science of it. — No Science of ajiy things if 

 an effential Property be not hio%vn^from which all its other Proper- 

 ties can be deduced. — The Nature and EJfence of every Motion con' 

 fi/ls of two things^ the Motive Force and the Dire(fl:ion. — The Di- 

 redtion of the Planetary Motion is a FaH that is knozvn. — Nothing 

 can be difcovered of the Planetary Motion, or of any thing in Nature, . 

 except from FaiSs. — The Bufinefs of Afronomy is not to inquire into 

 the Caufe of the Planetary Motion, . but to calculate that Motion, 

 and to difcover its Laws. — This the Notion ivhich Sir Ifaac bimfelf 



had of this Science DifincJion betwixt Metaphyfics, Phyfics, and 



Aftronomy. — Forces or Powers are latent things, to be difcovered 

 only by tb/ir Eflfe^^s. — The Ejfc^ of a Moving Force is Velocity. 



—That. 



