in the light of the sun everything in the nature of fire not only loses its brightness, but is outmatched and becomes inactive and blunted, since the sun’s heat scatters and dissipates its power. If then the moon possess a faint, feeble fire, being a star of somewhat turbid substance, as the Stoics themselves say, none of the effects which she now exhibits ought to follow, but the opposite in all respects; she ought to appear when she is now hidden, and be hidden when she now appears; be hidden, that is, all the time while she is dimmed by the surrounding [Sidenote: E] atmosphere, but shine brightly out at intervals of six months, or occasionally at intervals of five, when she passes under the shadow of the earth. (For of the 465 full moons at eclipse intervals, 404 give periods of six months, the remainder periods of five.) At such intervals then the moon ought to appear shining brightly in the shadow. But, as a fact, she is eclipsed and loses her light in the shadow, and recovers it when she has cleared the shadow; also she is often seen by day, which shows that she is anything but a fiery or starlike body.’ [Sidenote: F] XXI. When Lucius had said this, Pharnaces and Apollonides sprang forward together to oppose. Apollonides made way to Pharnaces, who observed that this is a very strong proof that the moon is a star or fire; for she does not disappear entirely in eclipses, but shows through with a grim ashy hue peculiar to herself. Apollonides objected to the word ‘shadow’, a term always applied by mathematicians to a region which is not [Sidenote: 934] lighted, whereas the heavens admit of no shadow. ‘This objection’, I said, ‘is contentious, and addressed to the name, not to the thing in any physical or mathematical sense. If any one should prefer to call the region blocked by the earth not “shadow”, but “an unlighted place”, it is still necessarily true that the moon when it reaches that region is darkened. It is merely childish’, I went on, ‘not to allow that the shadow of the earth reaches it, since we know that the shadow of the moon, falling upon the sight and reaching to the earth, causes an [Sidenote: B] eclipse of the sun. I will now turn to you, Pharnaces. That ashy charred colour in the moon, which you say is peculiar to her, belongs to a body which has density and depth. For no remnant or trace of flame will remain in rarefied bodies, nor can burning matter come into existence, without a substantial body, deep enough to allow of ignition and to maintain it, as Homer[347] has somewhere said: _When fire’s red flower was flown, and spent the flames, Which smoothed the embers._ For burning matter is evidently not fire but a body submitted to fire, and altered by it, which fire is attached to a solid stable mass and is permanent there, whereas flames are the kindling [Sidenote: C] and streaming away of rarefied fuel which is quickly dissolved because it is weak.