Page:Mathematical collections and translations, in two tomes - Salusbury (1661).djvu/131

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G. Galilæus, his Systeme.

swer, that of infinite one part is not greater than another, since both are infinite;Of infinity, one part is no bigger than another, although they are comparatively unequal. nor can it be said, that of the infinite number, an hundred thousand is a greater part than two, though that be fifty thousand times greater than this; and if to the moving of the Universe there be required a finite power, though very great in comparison of that which sufficeth to move the Earth onely; yet is there not implied therein a greater part of the infinite power, nor is that part lesse infinite which remaineth unimploy'd. So that to apply unto a particular effect, a little more, or a little lesse power, importeth nothing; besides that the operation of such vertue, hath not for its bound or end the Diurnal Motion onely; but there are several other motions in the World, which we know of, and many others there may be, that are to us unknown. Therefore if we respect the Moveables, and granting it as out of question, that it is a shorter and easier way to move the Earth, than the Universe; and moreover, having an eye to the so many other abreviations, and facilities that onely this way are to be obtained, an infallible Maxime of Aristotle, which he teacheth us, that, frustra fit per plura, quod potest fieri per pauciora, rendereth it more probable that the Diurnal Motion belongs to the Earth alone, than to the Universe, the Earth subducted.

Simpl.In reciting that Axiom, you have omitted a small clause, which importeth as much as all the rest, especially in our case, that is to say, the words æquè bene. It is requisite therefore to examine whether this Hypothesis doth equally well satisfie in all particulars, as the other.

Salv.The knowledg whether both these positions do æquè bene, satisfie, may be comprehended from the particular examination of the appearances which they are to satisfie; for hitherto we have discoursed, and will continue to argue ex hypothesi, namely, supposing, that as to the satisfaction of the appearances, both the assumptions are equally accomodated.In the Axiome Frustra fit per plura, &c. the addition of æque benè, is superfluous. As to the clause which you say was omitted by me, I have more reason to suspect that it was superfluously inserted by you. For the expression æquè bene, is a relative that necessarily requireth two terms at least, for a thing cannot have relation to its self, nor do we say, v. gr. rest to be equally good, as rest. And because, when we say, that is done in vain by many means, which may be done with fewer, we mean, that that which is to be done, ought to be the same thing, not two different ones; and because the same thing cannot be said to be done as well as its self; therefore, the addition of the Phrase æquè bene is superfluous, and a relation, that hath but one term onely.

Sagr.Unlesse you will have the same befal us, as did yesterday, let us return to our matter in hand; and let Simplicius be-

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