Page:Mathematical collections and translations, in two tomes - Salusbury (1661).djvu/140

 by Copernicus. Which arguments, as being of somewhat a different nature, may be produced, after we have examined the strength of these already propounded.

What say you Simplicius? do you think that Salviatus is Master of, and knoweth how to unfold the Ptolomean and Aristotelian arguments? Or do you think that any Peripatetick is equally verst in the Copernican demonstrations?

Were it not for the high esteem, that the past discourses have begot in me of the learning of Salviatus, and of the acutenesse of Sagredus, I would by their good leave have gone my way without staying for their answers; it seeming to me a thing impossible, that so palpable experiments should be contradicted; and would, without hearing them farther, confirm my self in my old perswasion; for though I should be made to see that it was erroneous, its being upheld by so many probable reasons, would render it excuseable. And if these are fallacies, what true demonstrations were ever so fair?

Yet its good that we hear the responsions of Salviatus; which if they be true, must of necessity be more fair, and that by infinite degrees; and those must be deformed, yea most deformed, if the Metaphysical Axiome hold, That true and fair are one and the same thing; as also false and deformed. Therefore Salviatus let's no longer lose time.

The first Argument alledged by Simplicius, if I well remember it, was this. The Earth cannot move circularly, because such motion would be violent to the same, and therefore not perpetual: that it is violent, the reason was: Because, that had it been natural, its parts would likewise naturally move round, which is impossible, for that it is natural for the parts thereof to move with a right motion downwards. To this my reply is, that I could gladly wish, that Aristotle had more cleerly exprest himself, where he said; That its parts would likewise move circularly; for this moving circularly is to be understood two wayes, one is, that every particle or atome separated from its Whole would move circularly about its particular centre, describing its small Circulets; the other is, that the whole Globe moving about its centre in twenty four hours, the parts also would turn about the same centre in four and twenty hours. The first would be no lesse an impertinency, than if one should say, that every part of the circumference of a Circle ought to be a Circle; or because that the Earth is Spherical, that therefore every part thereof be a Globe, for so doth the Axiome require: Eadem est ratio totius, & partium. But if he took it in the other sense, to wit, that the parts in imitation of the Whole should move naturally round the Centre of the whole Globe in twenty four hours, I say, that they do so; and it concerns you,