Page:Mathematical collections and translations, in two tomes - Salusbury (1661).djvu/58

 principle of the Elements. Which is manifest, for that if I aske the Peripatetick, if, being of opinion that Cœlestial bodies are incorruptibe and eternal, he believeth that the Terrestial Globe is not so, but corruptible and mortal, so that there shall come a time, when the Sun and Moon and other Stars, continuing their beings and operations, the Earth shall not be found in the World, but shall with the rest of the Elements be destroyed and annihilated, I am certain that he would answer me, no: therefore generation and corruption is in the parts and not in the whole; and in the parts very small and superficial, which are, as it were, incensible in comparison of the whole masse. And because Aristotle deduceth generation and corruption from the contrariety of streight motions, let us remit such motions to the parts, which onely change and decay, and to the whole Globe and Sphere of the Elements, let us ascribe either the circular motion, or a perpetual consistance in its proper place: the only affections apt for perpetuation, and maintaining of perfect order. This which is spoken of the Earth, may be said with the same reason of Fire, and of the greatest part of the Air; to which Elements, the Peripateticks are forced to ascribe for intrinsical and natural, a motion wherewith they were never yet moved, nor never shall be; and to call that motion preternatural to them, wherewith, if they move at all, they do and ever shall move. This I say, because they assign to the Air and Fire the motion upwards, wherewith those Elements were never moved, but only some parts of them, and those were so moved onely in order to the recovery of their perfect constitution, when they were out of their natural places; and on the contrary they call the circular motion preternatural to them, though they are thereby incessantly moved: forgeting, as it seemeth, what Aristotle oft inculcateth, that nothing violent can be permanent.

To all these we have very pertinent answers, which I for this time omit, that we may come to the more particular reasons, and sensible experiments, which ought in conclusion to be opposed, as Aristotle saith well, to whatever humane reason can present us with.

What hath been spoken hitherto, serves to clear up unto us which of the two general discourses carrieth with it most of probability, I mean that of Aristotle, which would perswade us, that the sublunary bodies are by nature generable, and corruptible, &c. and therefore most different from the essence of Cœlestial bodies, which are impassible, ingenerable, incorruptible, &c. drawn from the diversity of simple motions; or else this of Salviatus, who supposing the integral parts of the World to be disposed in a perfect constitution, excludes by necessary conse-