Page:The Mathematical Principles of Natural Philosophy - 1729 - Volume 1.djvu/33

Rh rightly explained by their extenion, mobility and impenetrability.

Some I know diapprove this concluion, and mutter omething about occult qualities. They continually are cavilling with us, that gravity is an occult property; and occult caues are to be quite banihed from philoophy. But to this the anwer is eay; that thoe are indeed occult caues whoe exitence is occult; and imagined but not proved; but not thoe whoe real exitence is clearly demontrated by obervations. Therefore gravity can by no means be called an occult caue of the celetial motions; becaue it is plain from the phenomena that uch a virtue does really exit. Thoe rather have recoure to occult caues; who et imaginary vortices, of a matter entirely fictious, and imperceptible by our enes, to direct thoe motions.

But hall gravity be therefore called an occult caue, and thrown out of philoophy, becaue the caue of gravity is occult and not yet dicovered? Thoe who affirm this, hould be careful not to fall into an aburdity that may overturn the foundations of all philoophy. For caues ue to proceed in a continued chain from thoe that are more compounded to thoe that are more imple; when we are arrived at the mot imple caue we can go no farther. Therefore no mechanical account or explanation of the mot imple caue is to be expected or given; for if it could be given, the caue were not the mot imple. Thee mot imple caues will you then call occult, and reject them? Then you mut reject thoe that immediately depend upon them, and thoe which depend upon thee lat, Rh