Page:The Gradual Acceptance of the Copernican Theory of the Universe.djvu/54

 ": Such was the old idea of Philolaus, Timaeus, Ecphantes, Seleucus, Aristarchus of Samos, Archimedes and Eudoxus, which Copernicus has renewed in our time. But it can easily be refuted by its shallowness although no one has done it thoroughly.

": What arguments do they rely on who hold that the earth is revolved and that the sun forsooth is still?

": Because the comprehension of the human mind cannot grasp the incredible speed of the heavenly spheres and especially of the tenth sphere which must be ten times greater than that of the eighth, for in twenty-four hours it must traverse 469,562,845 miles, so that the earth seems like a dot in the universe. This is the chief argument. Besides this, we get rid entirely of epicycles in representing the motions of the planets, and what is taught concerning the motion of trepidation in the eighth sphere vanishes. Also, there is no need for the ninth and tenth spheres. There is one argument which they have omitted but which seems to me more efficacious than any, viz.: rest is nobler than movement, and that celestial and divine things have a stable nature while elemental things have motion, disturbance and unrest; therefore it seems more probable that the latter move rather than the former. But while serious absurdities result from the idea of Eudoxus, far more serious ones result from that of Copernicus.

": What are these absurdities?

": Eudoxus knew nothing of trepidation, so his idea seems to be less in error. But Copernicus, in order to uphold his own hypothesis, claims the earth has three motions, its diurnal and annual ones, and trepidation; if we add to these the pull of weight towards the center, we are attributing four natural motions to one and the same body. If this is granted, then the very foundations of physics must fall into ruins; for all are agreed upon this, that each natural body has but one motion of its own, and that all others are said to be either violent or voluntary. Therefore, since he claims the earth is agitated by four motions, one only can be its own, the others must be confessedly violent; yet nothing violent in nature can endure continuously. Furthermore the earth is not moved by water, much less by the motion of air or fire in the way we have stated the heavens are moved by the revolutions of the enveloping heavens. Copernicus further does not claim that all the heavens are immobile but that some are moved, that is, the moon, Mercury. Venus, Mars, Jupiter and Saturn. But why such diversity? No one in his senses, or imbued with the slightest knowledge of physics, will ever think that the earth, heavy and unwieldy from 46