the opinions of his precursor, on this occasion. After acknowledging that the Newtonian system prevailed universally in Great Britain, and pretty generally throughout the rest of Europe, he asks—“Shall we then hear any thing against the Newtonian principles, in Answer?” He adds—“I answer, yes.” After rendering a constrained kind of compliment to the great Newton, for his “inexpressible service to Philosophy”—“so far as he adhered to his own plan,”—he proceeds with introducing “A few Thoughts on Space, Dimension, and the Divisibility of Matters _in infinitum_.” ----- Footnote 180: That eminent mathematician and astronomer, Mr. Roger Cotes,[180a] in an excellent preface to his edition of Sir Isaac Newton’s _Mathematica Principia Philosophiæ Naturalis_, has explained the true method of philosophising; shewn the foundation on which the Newtonian system was built; and refuted the objections of the Cartesians, and all other philosophers, against it. In this preface, Mr. Cotes has ably answered those, who contended, that gravity or attraction, in the system of Newton, was not a clearer principle, nor one more fit to explain the phænomena of nature, than the occult qualities of the peripatetics: for, there were still philosophers, such as they were, who persisted in that absurd opinion! “Gravity,” said the objectors, “is an occult cause; and occult causes have nothing to do with true philosophy.” To which Mr. Cotes made this lucid reply:—“Occult causes are not those whose existence is most clearly demonstrated by observation and experiment; but those only whose existence is occult, fictitious, and supported by no proofs. Gravity, therefore, can never be called an occult cause of the planetary motions; since it has been demonstrated from the phænomena, that this quality really exists. Those rather have recourse to occult causes, who make vortices to govern the heavenly motions; vortices, composed of a matter entirely fictitious, and unknown to the senses. But, shall gravity therefore be called an occult cause, because the cause of gravity is occult, and as yet undiscovered? Let those who affirm this, beware of laying down a principle which will serve to undermine the foundation of every system of philosophy that can be established. For causes always proceed, by an uninterrupted connexion, from those that are compound, to those that are more simple; and when you shall have arrived at the most simple, it will be impossible to proceed further. Of the most simple cause, therefore, no mechanical solution can be given; for if there could, it would not be the most simple. Will you then call these most simple causes _occult_, and banish them from philosophy? You may so; but you must banish at the same time the causes that are next to them, and those again that depend upon the causes next to them, till philosophy, at length, will be so thoroughly purged of causes, that