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Book II, Chapters 2-3. Of the Form and Nature of the World
That the world has the form of a perfect globe we learn from the name which has been uniformly given to it, as well as from numerous natural arguments. For not only does a figure of this kind return everywhere into itself and sustain itself, also including itself, requiring no adjustments, not sensible of either end or beginning in any of its parts, and is best fitted for that motion, with which, as will appear hereafter, it is continually turning round; but still more, because we perceive it, by the evidence of the sight, to be, in every part, convex and central, which could not be the case were it of any other figure.
The rising and the setting of the sun clearly prove, that this globe is carried round in the space of twenty-four hours, in an eternal and never-ceasing circuit, and with incredible swiftness. I am not able to say, whether the sound caused by the whirling about of so great a mass be excessive, and, therefore, far beyond what our ears can perceive, nor, indeed, whether the resounding of so many stars, all carried along at the same time and revolving in their orbits, may not produce a kind of delightful harmony of incredible sweetness. To us, who are in the interior, the world appears to glide silently along, both by day and by night.
Various circumstances in nature prove to us, that there are impressed on the heavens innumerable figures of animals and of all kinds of objects, and that its surface is not perfectly polished like the eggs of birds, as some celebrated authors assert. For we find that the seeds of all bodies fall down from it, principally into the ocean, and, being mixed together, that a variety of monstrous forms are in this way frequently produced. And, indeed, this is evident to the eye; for, in one part, we have the figure of a wain, in another of a bear, of a bull, and of a letter; while, in the middle of them, over our heads, there is a white circle.
With respect to the name, I am influenced by the unanimous opinions of all nations. For what the Greeks, from its being ornamented, have termed cosmos, we, from its perfect and complete elegance, have termed mundus. The name caelum, no doubt, refers to its being engraven, as it were, with the stars, as Varro suggests. In confirmation of this idea we may adduce the Zodiac, in which are twelve figures of animals; through them it is that the sun has continued its course for so many ages.