Page:Mathematical collections and translations, in two tomes - Salusbury (1661).djvu/257

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Dialogue. II.
231

The second, that Nulla res seipsam producat; [i. e.] that nothing produceth it self: from whence it follows, that it is not possible that the move and moved should be totally the same thing: And this is manifest, not onely in things that are moved by an extrinsick mover; but it is gathered also from the principles propounded, that the same holdeth true in the natural motion dependent on an intrinsick principle; otherwise, being that the mover, as a mover, is the cause, and the thing moved, as moved, is the effect, the same thing would totally be both the cause and effect. Therefore a body doth not move its whole self, that is, so as that all moveth, and all is moved; but its necessary in the thing moved to distinguish in some manner the efficient principle of the motion, and that which with that motion is moved. The third Axiom is, that in rebus quæ sensui subjiciuntur, unum, quatenus unum, unam solam rem producat; i. e. That in things subject to the senses, one, as it is one, produceth but onely one thing: That is, the soul in animals produceth its true divers operations, as the sight, the hearing, the smell, generation, &c. but all these with several instruments. And in short, in things sensible, the diversity of operations, is observed to derive it self from the diversity that is in the cause.A simple body as the Earth, cannot move with three several motions. Now if we put all these Axioms together, it will be a thing very manifest, that one simple body, as is the Earth, cannot of its own nature move at the same time with three motions, very divers: For by the foregoing suppositions, all moveth not its self all; it is necessary therefore to distinguish in it three principles of its three motions; otherwise one and the same principle would produce many motions; but if it contein in it three principles of natural motions, besides the part moved, it shall not be a simple body, but compounded of three principle movers,The Earth cannot move with any of the motions assigned it by Copernicus. and of the part moved. If therefore the Earth be a simple body, it shall not move with three motions; nay more, it will not move with any of those which Copernicus ascribeth to it, it being to move but with one alone, for that it is manifest, by the reasons of Aristotle, that it moveth to its centre, as its parts do shew, which descend at right angles to the Earths Spherical Surface.

Salv.Many things might be said, and considered touching the connection of this argument;Answers to the arguments contrary to the Earths motion, taken ex rerum natura. but in regard that we can resolve it in few words, I will not at this time without need inlarge upon it; and so much the rather, because the same Author hath furnished me with an answer, when he saith that from one sole prinple in animals, there are produced divers operations; so that for the present my answer shall be, that in the same manner the Earth from one onely principle deriveth several operations.

Simpl.But this answer will not at all satisfie the Author who

makes