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Now they first see the moon’s greatness, beauty, and nature, which is not simple nor unmixed, but a composition as it were of earth and star. For as the earth mixed with wind and moisture becomes soft, and as the blood tempered with the flesh gives it sense; so they say that the moon, being mingled with an ethereal quintessence even to the very bottom, is animated, becomes fruitful, and generative, and is equally counterpoised with ponderosity and lightness. For even the world itself, being composed of some things naturally moving upwards and others by nature tending downwards, is exempt from all local motion or change of place. These things also Xenocrates seems by a certain divine reasoning to have understood, having taken his first light from Plato. For Plato it was who first affirmed that every star is compounded of fire and earth, by the means of certain intermediate natures given in proportion; forasmuch as nothing can be an object of human sense which has not in some proportion a mixture of earth and light. Now Xenocrates says that the stars and the sun are composed of fire and the first or primitive solid; the moon of the second solid and its own peculiar air; and the earth, of water, fire, and the third solid. For neither is the solid alone by itself, nor the rare alone by itself, capable or susceptible of a soul. And let thus much suffice for the substance of the moon.
