with nearly the same Velocity , as if it had been a Stone.
Some think to illustrate this Descent of Heavy Bodies, by comparing it with the Vertue of the Loadstone; but setting aside the difference there is in the manner of their Attractions, the Loadstone drawing only in and about its Poles, and the Earth near equally in all Parts of its Surface, this Comparison avails no more than to explain ignotum per æque ignotum.
Others assign a certain Sympæthetical Attraction between the Earth and its Parts, whereby they have, as it were, a desire to be united, to be the Cause we enquire after: But this is so far from explaining the Modus, that it is little more, than to tell us in other Terms, that Heavy Bodies descend, because they descend.
This, I say, not that I can pretend to substitute any Solution of this Important Philosophical Problem, that shall more happily explicate the Appearances of Gravity; only it may be serviceable to those with whom the Credit of great Authors sways much, and who too readily assent in Verba Magistri, to let them see that their Books are not always infallible: Besides, the detection of Errors is the first and surest Step towards the discovery of Truth.
Though the efficient Cause of Gravity be so obscure, yet the final Cause thereof is clear enough; for it is by this single Principle, that the Earth and all the Cœlestial Bodies are kept from Dissolution; the least of their Particles not being suffer'd to recede far from their Surfaces, without being immediately brought down again by Virtue of this Natural Tendency; which, for their Preservation, the Infinite Wisdom of their Creator has ordained to be towards each of their Centers; nor can the Globes of the Sun and Planets otherwise be destroy'd, but by taking from them this Power of keeping their Parts united.
The Affections or Properties of Gravity , and its manner of acting upon Bodies falling ,