This is at once an excellent ally to those who thrust the air into depths and gullies on the moon, and also quite disposes of you, who strangely compound her globe of air and fire. For it is impossible [Sidenote: F] that shadow should be left on her surface when the sun touches with his light all that part of the moon which is framed within our own field of vision.’ VI. Here Pharnaces, while I was still speaking, broke in: ‘Round it goes again, the old scene-shifter of the Academy brought out against us; they amuse themselves with arguing against other people, but in no case submit to be examined on their own views, they treat their opponents as apologists, not accusers. I can speak for myself at any rate; you are not going to draw me on to-day to answer your charges against the Stoics, unless we first get an account of your conduct in turning the universe upside down.’ Lucius smiled: ‘Yes, my friend,’ he said, ‘only do not threaten us with the writ of heresy, such as Cleanthes used to think that the Greeks should have [Sidenote: 923] had served upon Aristarchus of Samos, for shifting the hearth of the universe, because that great man attempted “to save phenomena” with his hypothesis that the heavens are stationary, while our earth moves round in an oblique orbit, at the same time whirling about her own axis. We Academics have no view of our own finding, but do tell me this—why are those, who assume that the moon is an earth, turning things upside down, any more than you, who fix the earth where she is, suspended in mid air, a body considerably larger than the moon? [Sidenote: B] At least mathematicians tell us so, calculating the magnitude of the obscuring body from what takes place in eclipses, and from the passages of the moon through the shadow. For the shadow of the earth is less as it extends, because the illuminating body is greater, and its upper extremity is fine and narrow, as even Homer,[310] they say, did not fail to notice. He called night “pointed” because of the sharpness of the shadow. Such, at any rate, is the body by which the moon is caught in her eclipses, and yet she barely gets clear by a passage equal to three of her own diameters. Just consider how many moons go to make an earth, if the earth cast a shadow as broad, at its shortest, as three moons. Yet you have fears for the moon lest she should tumble, while as for our earth, Aeschylus[311] has perhaps satisfied you that Atlas [Sidenote: C] _Stands, and the pillar which parts Heaven and Earth His shoulders prop, no load for arms t’ embrace._