We cannot, Apollonius says, see through the stars what is beyond, but sight passes easily through the comets. Well, in the first place, if 2 that is the case, it is not so in the part of the body which consists of dense solid fire, but only where the dispersed glow extends as it breaks up into the appearance of hair. One can see through the gaps in the fire and not through the fire itself. Stars again, it is said, are all round, comets extended; whence it is plain that they are not true stars. But who, pray, will allow that comets are long? Their tendency like that of other stars is to a globe shape, only the light from them is prolonged. The sun shoots out his rays far and wide, but has himself a shape different from that of the light that streams from him. So in comets, the body is rounded, but the glow from them presents the appearance of being longer than that of the other stars. XXVII Why is this so, you ask. Do you tell me first why the light the 1 moon receives is wholly unlike the sun although she receives it from the sun. Why is it now ruddy, now pale? why is her colour ashen or black when she is cut off from the sun’s view? Or tell me why all the stars have aspects to some extent dissimilar to one another and all as different as possible from the sun. It is no hindrance to their being true stars that they are not all alike; so there is nothing to prevent comets from being permanent through all time, sharing the same destiny as the other stars, even though they have not an appearance like theirs. Besides, is not the universe, if you will only examine it 2 carefully, made up of contrarieties? Why is it that the sun should be always blazing hot in Leo, scorching the ground with his fierce glow, while in Aquarius he brings winter’s chain and closes the rivers with ice? The one constellation is subject to the same law as the other, though its characteristics and influence are so different. Aries again rises in a moment, Libra lifts its scales very slowly; yet the one sign is of the same nature as the other, though that one mounts in a brief space, this comes forth very deliberately. Do you not see, too, how contrary the elements are to one another? They are heavy and 3 light, cold and hot, moist and dry. The whole concord of the universe is a harmony of discords. You say a comet is not a star, because its form does not correspond to the type, but is unlike other stars. You can see, no doubt, how very like that star that returns to its place after thirty years is to this which revisits its haunt within the year! Nature does not turn out her work according to a single pattern; she prides herself upon her power of variation. She has made some 4 things larger, some swifter than others; some stronger, some more limited in power; some she has separated from the crowd, that their splendid isolation might render their progress conspicuous; some she has consigned to a place in the common herd.