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HISTORICAL VIEW OF THE

exposition of the mechanism of the heavens, whichconstitutes the third book; after that beautiful deve-lopement of the entire system of forces which guideand modify the revolutions of the planets primary andsecondary, Newton concludes the whole with a sublimeapplication, worthy of the preceding parts of the work,in which he deduces, in the direct line of argumentfrom the laws of material phenomena, the proofs of theexistence of the Great First Cause, and the evidencesof the divine perfections.

In the view we have before taken of the progress ofenquiry in the several departments on which the disco-veries of Newton shed so new and brilliant a light, wehave clearly traced at what point the labours of preced-ing philosophers had failed; and, on the other hand,precisely how much they had effected, and to whatamount, each in their several ways, they had contributedtowards the great work which it was reserved for New-ton to complete.

The mathematical methods of investigation had been,in some measure, prepared by the invention of Newton ’simmediate precursors, and the geometrical truths which,from the immovable foundation of the whole, hadbeen established by the ancients. But the discoveriesof Plato , Euclid, and Apollonius, and the investigationsof Kepler, Wallis, and Barrow, wanted their connectingprinciple, till it was supplied in the powerful methodscreated by the master mind of Newton .

The dynamical and mechanical truths contributed byArchimedes and Galileo ; the laws of motion and forcecollected by Wren and Huyghens ; the notions of at-traction expounded by Hooke, had been brought toge-ther, but not as yet reduced into systematic connection.

The phenomena of the heavens, recorded from theinfancy of the world, had been referred to certain laws,and order educed out of apparent confusion by the suc-cessive labours of astronomers; the magnitude of theearth had been measured, and computation had beenrendered easy by logarithms.