The Stoics declare, that in magnitude it exceeds the earth, just as the sun itself doth. Parmenides, that it is equal to the sun, from whom it receives its light.
CHAPTER XXVII. OF THE FIGURE OF THE MOON.
The Stoics believe that it is of the same figure with the sun, spherical. Empedocles, that the figure of it resembles a quoit. Heraclitus, a boat. Others, a cylinder.
CHAPTER XXVIII. FROM WHENCE IS IT THAT THE MOON RECEIVES HER LIGHT?
Anaximander thinks that she gives light to herself, but it is very slender and faint. Antiphon, that the moon shines by its own proper light; but when it absconds itself, the solar beams darting on it obscure it. Thus it naturally happens, that a more vehement light puts out a weaker; the same is seen in other stars. Thales and his followers, that the moon borrows all her light of the sun. Heraclitus, that the sun and moon are after the same manner affected; in their configurations both are shaped like boats, and are made conspicuous to us by receiving their light from moist exhalations. The sun appears to us more refulgent, by reason it is moved in a clearer and purer air; the moon appears more duskish, it being carried in an air more troubled and gross.
CHAPTER XXIX. OF THE ECLIPSE OF THE MOON.
Anaximenes believes that the mouth of the wheel, about which the moon is turned, being stopped is the cause of an eclipse. Berasus, that it proceeds from the turning of the dark side of the lunar orb towards us. Heraclitus, that it is performed just after the manner of a boat turned upside downwards. Some of the Pythagoreans say, that the splendor arises from the earth, its obstruction from the Antichthon (or counter-earth). Some of the later philosophers, that there is such a distribution of the lunar flame, that it gradually and in a just order burns until it be full moon; in like manner, that this fire decays by degrees, until its conjunction with the sun totally extinguisheth it. Plato, Aristotle, the Stoics, and all the mathematicians agree, that the obscurity with which the moon is every month affected ariseth from a conjunction with the sun, by whose more resplendent beams she is darkened; and the moon is then eclipsed when she falls upon the shadow of the earth, the earth interposing between the sun and moon, or (to speak more properly) the earth intercepting the light of the moon.