Nature might be aſſiſted every where by a ſubtile æther pervading and filling all things; which cannot be ſaid however, ſince we have ſhewn from the phænonena of the Comets, that this æther is of no efficacy at all; or they will ſay, that it became ſo by the ſame will of God for ſome unknown end; which ought not to be ſaid, becauſe for the ſame reaſon a different conſtitution may be as well ſuppoſed, or laſtly, they will not ſay that it was cauſed by the will of God, but by ſome neceſſity of its nature. Therefore they will at laſt ſink into the mire of that infamous herd; who dream that all things are governed by Fate, and not by Providence; and that matter exiſts by the neceſſity of its nature always and every where, being infinite and eternal. But ſuppoſing theſe things; it muſt be alſo every where uniform; for variety of forms is entirely inconſiſtent with neceſſity. It muſt be alſo unmoved; for if it be neceſſarily moved in any determinate direction, with any determinate velocity, it will by a like neceſſity be moved in a different direction with a different velocity; but it can never move in different directions with different velocities; therefore it muſt be unmoved. Without all doubt this World, ſo diverſified with that variety of forms and motions we find in it, could ariſe from nothing but the perfectly free will of God directing and preſiding over all.
From this fountain it is that thoſe laws, which we call the laws of Nature, have flowed; in which there appear many traces indeed of the moſt wiſe contrivance, but not the leaſt ſhadow of neceſſity. Theſe therefore we muſt not ſeek from uncertain
conjectures; but learn them from obſervations and ex-
