98. Could Mr. Barrow fo far deceive himfelf as to think that he was promoting the cause of Science, by advancing fuch an absurd, fuch an unfcientific Affertion? What more ef fectual bar could he put on the door of Know ledge than to impofe on the votaries, the more than Herculean Labour of producing a Principle of Nature which counteracts all her operations? A Principle which Nature directly dif owns and difavows, ever invariably acting by confiftent and uncontradictory means.

Are there not fufficient reafons to believe that Electricity may be much better accounted for without attraction, than with it? And fince fuch a Power, as a phyfical Agent to perform both, is abfolutely impoffible in the nature of things, niuft it not be more fatisfactory to attempt a rational method, whereby attraction may be totally excluded all refearches after natural Caufes? To me, at least, a total exclufion of fuch a mistaken Principle appears to be abfolutely neceffary to render our natural a rational Philofophy.

Attraction fhall therefore be the Subject of my next Enquiry. But as the retention of that Term has been fo ftrenuously defended, I can not help foreseeing that my utmost Efforts to remove the almoft invincible prejudice in its favour may poffibly prove vain and fruitless : But as I find Mr. Jones has copiously discuss'd that Subject, I fhall take the liberty of laying his Sentiments of it before the Reader in his

own words, which, on that and every other Topic he handles, are fo pertinent, elegant, and entertaining, that I flatter myself I fhall rather merit the Thanks than the Blame of my Reader for the largenefs of my Quotations from him.

CHAP. VII. PART III.

SECTION 99.

The Opinion of Sir Ifaac Newton, and of fome of the most eminent of bis Followers, relating to Attraction and Gravity, confider'd at large.

"I

N the former Part of this Treatife, fays Mr Jones, " I have made it appear, that the only rational and intelligible Philofophy is that which attributes all motion to the action of matter upon matter; or, which is the fame thing, that maintains an agency of material and fecondary caufes under the direction of God, the moral Governor of the World, and the fupreme Cause of all things.'

22

99. "To fuch a Philofophy as this, I have attempted to clear the way by removing all the principal objections of our modern learned Men; and if the fuppofed evidence for a vacuum, depending upon the famous theory of refiftances,

which gained fo much credit with Dr. Cotes, and many others, as to be unhappily mistaken for a Demonftration; if this, I fay, has been obviated to the fatisfaction of the learned Reader, what remains to be done will rather be a work of ease and amusement, than of difficult and doubtful difputation."

101. "For if the notion of a vacuum be un fupported, and falfe in itself, nothing that is advanced in the mathematical Philofophy, rélating to phyfical Caufes, can poflibly be right. Where that Philofophy has mistaken or misreprefented the nature of thefe caufes, it will be found inconfiftent either with itself or with nature, and most probably with both; so that to detect the falfehood of it,we fhall have nothing to do, but to compare it with itself, and with thofe notions of the natural world, with which our Senfes and Experience will furnifh us. In this difquifition, we fhall have in review before us, a great variety of useful and curious Experiments, which cannot fail of giving some entertainment, to a mind that hath bestowed of its attention upon fuch fubjects."

any

102. "As my concern at present is barely with physical causes, no reader can be fo abfurd as to fufpect, that I am aiming at the demolition of all that is now called by the name of natural Philofophy, without doing me a manifest injuftice, and betraying his own want of Knowledge. The doctrine of unmechanical caufes, tho' the forwardness and indifcretion of fome Tt2 adven

adventurers may

have loaded it with a much

greater weight than it is able to bear, does yet make but an inconfiderable part of the eftablish'd Philofophy; and if it should hereafter. give place to fome more natural account of things, the remaining parts will always retain their prefent value. Such a work as that of Profeffor S' Gravefande will deferve the admiration of the ingenious, fo long as the world lasts; and that Man must have but an indifferent relish for the Sciences, who is not greatly delighted with the discoveries and improvements he may there meet with, in Mechanics, Optics, and Aftronomy. I fpeak this in much fincerity: And it is intended to obviate any prejudices that might be raised againft my defign, either wilfully or by mistake. To give offence is no part of my defign; and I am unwilling, that any well-defigning Person should think me to be poffeffed by a fpirit of detraction, while I am confcious to myself it is far from me, and that I write upon much higher motives. I am encouraged therefore to hope for the attention at leaft, if not the favour, of all candid Men and Lovers of phyfical truth, while I enquire into the fenfe and merit of those causes, by which the Author of Nature is now fuppofed to direct the natural world. "

103. “First then let us enquire, what kind of force or agency Sir Ifaac Newton and his followers would have us understand by the Terms Attraction and Repulfion.".

104.

"That Attraction hath been called in for the explication of natural appearances, both great and small, every Perfon must know, who has either heard or read any course of phyfical Lectures deliver'd in English within this last Century: It is looked upon, as a Principle, not to be approached without a degree of reverence, because the great Sir Ifaac Newton thought proper to make use of it; but if the word should have no fixed meaning, and should itfelf want an explication, it will explain nothing at all; it will be a word without an idea; and if we apply it to any particular cafe, we shall explain, as the phrafe is, ignotum per ignotius, a thing "unknown by another that is lefs "known." The word, if strictly taken, fignifies a drawing or pulling of one Body towards another: But as every Science hath a liberty of adopting its own Terms, provided it adds fuch a definition as will keep them clear of ambiguity, I fhall fpend no conjectures upon it, but try if I can settle the three following queftions, upon the best Authority that is to be had

Firft, Where Attraction is feated? for ex

ample, whether it be in the Earth, or in the Stone that falls down to it, or in both, or in neither, but in some substance exterior to both? Secondly, Whether it is to be understood as a Cause or as an Effect? And Thirdly, Whether it be a material Force, or an immaterial one? Under which heads, all that need be faid upon the fubject may eafily be reduced,'