Page:Mathematical collections and translations, in two tomes - Salusbury (1661).djvu/47

 may be assigned to the Universe, we shall rather find the Sun placed in it, as by the sequel you shall understand.

Now, like as from the consentaneous conspiration of all the parts of the Earth to form its whole, doth follow, that they with equal inclination concurr thither from all parts; and to unite themselves as much as is possible together, they there spherically adapt themselves; why may we not believe that the Sun, Moon, and other mundane Bodies, be also of a round figure, not by other than a concordant instinct, and natural concourse of all the parts composing them? Of which, if any, at any time, by any violence were separated from the whole, is it not reasonable to think, that they would spontaneously and by natural instinct return? and in this manner to infer, that the right motion agreeth with all mundane bodies alike.

Certainly, if you in this manner deny not onely the Principles of Sciences, but manifest Experience, and the Senses themselves, you can never be convinced or removed from any opinion which you once conceit, therefore I will choose rather to be silent (for, contra negantes principia non est disputandum) than contend with you. And insisting on the things alledged by you even now (since you question so much as whether grave moveables have a right motion or no) how can you ever rationally deny, that the parts of the Earth; or, if you will, that ponderous matters descend towards the Centre, with a right motion; whenas, if from a very high Tower, whose walls are very upright and perpendicular, you let them fall, they shall descend gliding and sliding by the Tower to the Earth, exactly in that very place where a plummet would fall, being hanged by a line fastned above, just there, whence the said weights were let fall? is not this a more than evident argument of the motions being right, and towards the Centre? In the second place you call in doubt, whether the parts of the Earth are moved, as Aristotle affirms, towards the Centre of the World; as if he had not rationally demonstrated it by contrary motions, whilst he thus argueth; The motion of heavie bodies is contrary to that of the light: but the motion of the light is manifest to be directly upwards, namely, towards the circumference of the World, therefore the motion of the heavie is directly towards the Centre of the World: and it happens per accidens, that it be towards the centre of the Earth, for that this striveth to be united to that. The seeking in the next place, what a part of the Globe of the Sun or Moon would do, were it separated from its whole, is vanity; because that thereby that is sought, which would be the consequence of an impossibility; in regard that, as Aristotle also demonstrates, the cœlestial bodies are impassible, impenetrable, and infrangible; so that such