Greek Texts & Translations

"An eclipse of the sun or moon may be due to the extinction of their light, just as within our own experience this is observed to happen ; and again by interposition of something else - whether it be the earth or some other invisible body like it. And thus we must take in conjunction the explanations which agree with one another, and remember that the concurrence of more than one at the same time may not impossibly happen. [He says the same in Book XII. of his "De Natura," and further that the sun is eclipsed when the moon throws her shadow over him, and the moon is eclipsed by the shadow of the earth ; or again, eclipse may be due to the moon's withdrawal, 10.1.97 and this is cited by Diogenes the Epicurean in the first book of his "Epilecta."]

"And further, let the regularity of their orbits be explained in the same way as certain ordinary incidents within our own experience ; the divine nature must not on any account be adduced to explain this, but must be kept free from the task and in perfect bliss. Unless this be done, the whole study of celestial phenomena will be in vain, as indeed it has proved to be with some who did not lay hold of a possible method, but fell into the folly of supposing that these events happen in one single way only and of rejecting all the others which are possible, suffering themselves to be carried into the realm of the unintelligible, and being unable to take a comprehensive view of the facts which must be taken as clues to the rest.

"The variations in the length of nights and days may be due to the swiftness and again to the slowness of the sun's motion in the sky, owing to the variations in the length of spaces traversed and to his accomplishing some distances more swiftly or more slowly, as happens sometimes within our own experience ; and with these facts our explanation of celestial phenomena must agree ; whereas those who adopt only one explanation are in conflict with the facts and are utterly mistaken as to the way in which man can attain knowledge.

"The signs in the sky which betoken the weather may be due to mere coincidence of the seasons, as is the case with signs from animals seen on earth, or they may be caused by changes and alterations in the air. For neither the one explanation nor the other is in conflict with facts, 10.1.99 and it is not easy to see in which cases the effect is due to one cause or to the other.

"Clouds may form and gather either because the air is condensed under the pressure of winds, or because atoms which hold together and are suitable to produce this result become mutually entangled, or because currents collect from the earth and the waters ; and there are several other ways in which it is not impossible for the aggregations of such bodies into clouds to be brought about. And that being so, rain may be produced from them sometimes by their compression, sometimes by their transformation ; 10.1.100 or again may be caused by exhalations of moisture rising ^note from suitable places through the air, while a more violent inundation is due to certain accumulations suitable for such discharge. Thunder may be due to the rolling of wind in the hollow parts of the clouds, as it is sometimes imprisoned in vessels which we use ; or to the roaring of fire in them when blown by a wind, ^note or to the rending and disruption of clouds, or to the friction and splitting up of clouds when they have become as firm as ice. 10.1.101 As in the whole survey, so in this particular point, the facts invite us to give a plurality of explanations. Lightnings too happen in a variety of ways. For when the clouds rub against each other and collide, that collocation of atoms which is the cause of fire generates lightning ; or it may be due to the flashing forth from the clouds, by reason of winds, of particles capable of producing this brightness ; or else it is squeezed out of the clouds when they have been condensed either by their own action or by that of the winds ; or again, the light diffused from the stars may be enclosed in the clouds, then driven about by their motion and by that of the winds, and finally make its escape from the clouds ; or light of the finest texture may be filtered through the clouds (whereby the clouds may be set on fire and thunder produced), and the motion of this light may make lightning ; or it may arise from the combustion of wind brought about by the violence of its motion and the intensity of its compression ; 10.1.102 or, when the clouds are rent asunder by winds, and the atoms which generate fire are expelled, these likewise cause lightning to appear. And it may easily be seen that its occurrence is possible in many other ways, so long as we hold fast to facts and take a general view of what is analogous to them. Lightning precedes thunder, when the clouds are constituted as mentioned above and the configuration which produces lightning is expelled at the moment when the wind falls upon the cloud, and the wind being rolled up afterwards produces the roar of thunder ; or, if both are simultaneous, the lightning moves with a greater velocity towards us