Page:Mathematical collections and translations, in two tomes - Salusbury (1661).djvu/62

 I verily believed otherwise, and conceited that Simplicius dissembled this exposition of the Text, that he might not charge his Master and Consectators, with a notion more absurd than the former. And what a folly it is to say the Cœlestial part is unalterable, because no stars do generate or corrupt therein? What then? hath any one seen a Terrestrial Globe corrupt, and another regenerate in its place? And yet is it not on all hands granted by Philosophers, that there are very few stars in Heaven less than the Earth, but very many that are much bigger? So that for a star in Heaven to corrupt, would be no less than if the whole Terrestrial Globe should be destroy'd. Therefore, if for the true proof of generation and corruption in the Universe, it be necessary that so vast bodies as a star, must corrupt and regenerate, you may satisfie your self and cease your opinion; for I assure you, that you shall never see the Terrestrial Globe or any other integral body of the World, to corrupt or decay so, that having been beheld by us for so many years past, they should so dissolve, as not to leave any footsteps of them.

But to give Simplicius yet fuller satisfaction, and to reclaim him, if possible, from his error; I affirm, that we have in our age new accidents and observations, and such, that I question not in the least, but if Aristotle were now alive, they would make him change his opinion; which may be easily collected from the very manner of his discoursing: For when he writeth that he esteemeth the Heavens inalterable, &c. because no new thing was seen to be begot therein, or any old to be dissolved, he seems implicitely to hint unto us, that when he should see any such accident, he would hold the contrary: and confront, as indeed it is meet, sensible experiments to natural reason: for had he not made any reckoning of the senses, he would not then from the not seeing of any sensible mutation, have argued immutability.

Aristotle deduceth his principal Argument à priori, shewing the necessity of the inalterability of Heaven by natural, manifest and clear principles; and then stablisheth the same à posteriori, by sense, and the traditions of the antients.

This you speak of is the Method he hath observed in delivering his Doctrine, but I do not bethink it yet to be that wherewith he invented it; for I do believe for certain, that he first procured by help of the senses, such experiments and observations as he could, to assure him as much as it was possible, of the conclusion, and that he afterwards sought out the means how to demonstrate it: For this is the usual course in demonstrative Sciences, and the reason thereof is, because when the conclusion is true, by help of resolutive Method, one may hit upon some proposition before demonstrated, or come to some principle known