mean, that as they move to the centre of the Earth, they move to their Whole, and to their Universal Mother: and we are still farther so free, that we will suffer our selves to be perswaded, that their natural instinct is,Grave bodies may more rationally be affirmed to tend to the Centre of the Earth, than of the Universe. not to go towards the centre of the Earth, but towards that of the Universe; which we know not where to find, or whether it be or no; and were it granted to be, it is but an imaginary point, and a nothing without any quality. As to what Simplicius said last, that the contending whether the parts of the Sun, Moon, or other cœlestial Body, separated from their Whole, should naturally return to it, is a vanity, for that the case is impossible; it being clear by the Demonstrations of Aristotle, that the cœlestial Bodies are impassible,The conditions and attributes which differ the cœlestial bodies from Elementary, depend on the motions assigned them by Arist. impenetrable, unpartable, &c. I answer, that none of the conditions, whereby Aristotle distinguisheth the Cœlestial Bodies from Elementary, hath other foundation than what he deduceth from the diversity of the natural motion of those and these; insomuch that it being denied, that the circular motion is peculiar to Cœlestial Bodies, and affirmed, that it is agreeable to all Bodies naturally moveable, it is behoofull upon necessary consequence to say, either that the attributes of generable, or ingenerable, alterable, or unalterable, partable, or unpartable, &c. equally and commonly agree with all worldly bodies, namely, as well to the Cœlestial as to the Elementary; or that Aristotle hath badly and erroneously deduced those from the circular motion, which he hath assigned to Cœlestial Bodies.
Simpl.This manner of argumentation tends to the subversion of all Natural Philosophy, and to the disorder and subversion of Heaven and Earth, and the whole Universe; but I believe the Fundamentals of the Peripateticks are such, that we need not fear that new Sciences can be erected upon their ruines.
Salv.Take no thought in this place for Heaven or the Earth, neither fear their subversion, or the ruine of Philosophy. As to Heaven, your fears are vain for that which you your self hold unalterable and impassible; as for the Earth, we strive to enoble and perfect it, whilst we make it like to the Cœlestial Bodies, and as it were place it in Heaven, whence your Philosophers have exiled it.The disputes and contradictions of Philosophers may conduce to the benefit of Philosophy. Philosophy it self cannot but receive benefit from our Disputes, for if our conceptions prove true, new Discoveries will be made; if false, the first Doctrine will be more confirmed. Rather bestow your care upon some Philosophers, and help and defend them; for as to the Science it self, it cannot but improve. And that we may return to our purpose, be pleased freely to produce what presents it self to you in confirmation of that great difference which Aristotle puts between the Cœlestial Bodies, and the Elementary parts of the World, in making those ingenerable,incor-
