Page:Mathematical collections and translations, in two tomes - Salusbury (1661).djvu/129

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G. Galilæus, his Systeme.

would never with his walking have arrived, if the Ship with its motion had not wafted him thither.

Sagr.Tell me secondly. That motion, which is communicated to any moveable by participation, whilest it moveth by it self, with another motion different from the participated, is it necessary, that it do reside in some certain subject by it self, or else can it subsist in nature alone, without other support.

Simpl.Aristotle giveth you an answer to all these questions,Motion cannot be made without its moveable subject. and tels you, that as of one sole moveable the motion is but one; so of one sole motion the moveable is but one; and consequently, that without the inherence in its subject, no motion can either subsist, or be imagined.

Sagr.I would have you tell me in the third place, whether you beblieve that the Moon and the other Planets and Cœlestial bodies, have their proper motions, and what they are.

Simpl.They have so, and they be those according to which they run through the Zodiack, the Moon in a Moneth, the Sun in a Year, Mars in two, the Starry Sphere in those so many thousand. And these are their proper, or natural motions.

Sagr.But that motion wherewith I see the fixed Stars, and with them all the Planets go unitedly from East to West, and return round to the East again in twenty four hours, how doth it agree with them?

Simpl.It suiteth with them by participation.

Sagr.This then resides not in them, and not residing in them, nor being able to subsist without some subject in which it is resident, it must of force be the proper and natural motion of some other Sphere.

Simpl.For this purpose Astronomers, and Philosophers have found another high Sphere, above all the rest, without Stars, to which Natural agreeth the Diurnal Motion; and this they call the Primum mobile; the which carrieth along with it all the inferiour Spheres, contributing and imparting its motion to them.

Sagr.But when, without introducing other Spheres unknown and hugely vast, without other motions or communicated raptures, with leaving to each Sphere its sole and simple motion, without intermixing contrary motions, but making all turn one way, as it is necessary that they do, depending all upon one sole principle, all things proceed orderly, and correspond with most perfect harmony, why do we reject this Phœnomenon, and give our assent to those prodigious and laborious conditions?

Simpl.The difficulty lyeth in finding out this so natural and expeditous way.

Sagr.