Page:Mathematical collections and translations, in two tomes - Salusbury (1661).djvu/262

 .But this would be to draw a further inconvenience upon himself, in that he holdeth, that the bare eye cannot be deceived in judging of the right motion of descending graves, and yet holds that it is deceived in beholding these other motions at such time as its visive vertue is perfected, and augmented to thirty times as much as it was before. We tell him therefore, that the Earth in like manner partaketh of the plurality of motions: and it is perhaps the same, whereby the Loadstone hath its motion downwards, as grave, and two circular motions, one Horizontal, and the other Vertical under the Meridian. But what more; tell me, Simplicius, between which do you think this Author would put a greater difference, 'twixt right and circular motion, or 'twixt motion and rest?

.'Twixt motion and rest, certainly. And this is manifest, for that circular motion is not contrary to the right, according to Aristotle; nay, he granteth that they may mix with each other; which it is impossible for motion and rest to do.

.Therefore its a proposition lesse improbable to place in one natural body two internal principles, one to right motion, and the other to circular, than two such interne principles one to motion, and the other to rest. Now both these positions agree to the natural inclination that resideth in the parts of the Earth to return to their whole, when by violence they are divided from it; and they onely dissent in the operation of the whole: for the latter of them will have it by an interne principle to stand still, and the former ascribeth to it the circular motion. But by your concession, and the confession of this Philosopher, two principles, one to motion, and the other to rest, are incompatible together, like as their effects are incompatible: but now this evenes not in the two motions, right, and circular, which have no repugnance to each other.

.Adde this more, that in all probability it may be that the motion, that the part of the Earth separated doth make whilst it returneth towards its whole, is also circular, as hath been already declared; so that in all respects, as far as concernes the present case, Mobility seemeth more likely than Rest. Now proceed, Simplicius, to what remains.

.The Authour backs his Argument with producing another absurdity, that is, that the same motions agree to Natures extreamly different; but experience sheweth, that the operations and motions of different natures, are different; and Reason confirmeth the same: for otherwise we should have no way left to know and distinguish of natures, if they should not have their particular motions and operations, that might guide us to the knowledge of their substances.