the last place, those, by which others may be perswaded, that the Earth is no less than the Moon, or any other Planet to be numbered amongst natural bodies that move circularly.
Sagr.I shall the more willingly incline to this, in that I am better satisfied with your Architectonical and general discourse, than with that of Aristotle, for yours convinceth me without the least scruple, and the other at every step crosseth my way with some block. And I see no reason why Simplicius should not be presently satisfied with the Argument you alledg, to prove that there can be no such thing in nature as a motion by a right line, if we do but presuppose that the parts of the Universe are disposed in an excellent constitution and perfect order.
Salv.Stay a little, good Sagredus, for just now a way comes into my mind, how I may give Simplicius satisfaction, provided that he will not be so strictly wedded to every expression of Aristotle, as to hold it heresie to recede in any thing from him. Nor is there any question to be made, but that if we grant the excellent disposition and perfect order of the parts of the Universe, as to local scituation, that then there is no other but the circular motion, and rest; for as to the motion by a right line, I see not how it can be of use for any thing, but to reduce to their natural constitution, some integral bodies, that by some accident were remov'd and separated from their whole, as we said above.
Let us now consider the whole Terrestrial Globe, and enquire the best we can, whether it, and the other Mundane bodies are to conserve themselves in their perfect and natural disposition. It is necessary to say, either that it rests and keeps perpetually immoveable in its place; or else that continuing always in its place, it revolves in its self; or that it turneth about a Centre, moving by the circumference of a circle.Arist. & Ptolomey make the Terrestrial Globe immoveable. Of which accidents, both Aristotle and Ptolomey, and all their followers say, that it hath ever observed, and shall continually keep the first, that is, a perpetual rest in the same place.It is better to say, that the Terrestrial Globe naturally resteth, than that it moveth directly downwards. Now, why, I pray you, ought they not to have said, that its natural affection is to rest immoveable, rather than to make natural unto it the motion * downwards, with which motion it never did or shall move? And as to the motion by a right line, they must grant us that Nature maketh use of it to reduce the * The word is, all' ingiù, which the Latine version rendreth sursùm, which is quite contrary to the Authors sense. small parts of the Earth, Water, Air, Fire, and every other integral Mundane body to their Whole, when any of them by chance are separated, and so transported out of their proper place; if also haply, some circular motion might not be found to be more convenient to make this restitution. In my judgment, this primary position answers much better, even according to Aristotles own method, to all the other consequences, than to attribute the straight motion to be an intrinsick and naturalprinciple
