Chap. i. PHILOSOPHICAL DISCOVERIES. 11

ns on the earth, and explaining by it the motions and influencesof the celestial bodies, in the most satisfactory manner; and hisdetermining the measures of the various motions that are conse-quences of this power, by so skilful an application of geometryto nature; all these had no merit with such philosophers, be-cause he did not assign the mechanical cause of gravity. Iknow not that ever it was made an objection to the circulationof the blood that there is no small difficulty in accounting forit mechanically; they who first extended gravity to air, vapour,and to all bodies round the earth, had their praise, though thecause of gravity was as obscure as before; or rather appearedmore mysterious, after they had shewn that there was no bodyfound near the earth, exempt from gravity, that might be sup-posed to be its cause. Why then were his admirable discove-ries, by which this principle was extended over the universe,so ill relished by some philosophers? The truth is, he had, withgreat evidence, overthrown the boasted schemes by which theypretended to unravel all the mysteries of nature; and thephilosophy he introduced, in place of them, carrying with it afincere confession of our being far from a complete and perfectknowledge of it, could not please those who had been ac-custom’d to imagine themselves postefs’d of the eternal reasonsand primary causes of all things.

• But to all such as have just 'notions of the great author ofthe universe, and of his admirable workmanship, Sir Isaac New-ton s caution and modesty will recommend his philosophy ; andeven the avowed imperfection of some parts of it will, to them,rather appear a consequence of its conformity with nature. Tosuch, all complete and finished systems must appear very*sus-picious : they will not be surprized that refined speculations,or even the labours of a few ages, are not sufficient to unsoldthe whole constitution of things, and trace every phænomenon

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