Book VII — Which Treats of Comets
I
1
2
3
4
No man is so utterly dull and obtuse, with head so bent on earth, as never to lift himself up and rise with all his soul to the contemplation of the starry heavens, especially when some fresh wonder shows a beacon-light in the sky. As long as the ordinary course of heaven runs on, custom robs it of its real size. Such is our constitution that objects of daily occurrence pass us unnoticed even when most worthy of our admiration. On the other hand, the sight even of trifling things is attractive if their appearance is unusual. So this concourse of stars, which paints with beauty the spacious firmament on high, gathers no concourse of the nation. But when there is any change in the wonted order, then all eyes are turned to the sky. The sun has no observer unless he is in eclipse. No one watches the moon unless she suffer obscuration. But then whole cities cry out, groundless superstition drives every one into panic. And yet how much greater are the ordinary movements of the sun! He takes, so to speak, as many steps as there are days, completing the year in his circuit. From the summer solstice he turns back to the lessening days, from the solstice he slopes his rays,90 and gives more room to the nights; he occults the planets; though so much larger than the earth he does not burn it up, but cheers it by his heat, which he so regulates as to make it alternately more intense and more subdued. He never fills up with light, nor yet obscures, the moon, except when she is right opposite to him. All this we allow to pass unnoticed as long as the usual order is preserved. But if there is any disturbance or any extraordinary light displayed in the sky, we gaze at it, ask questions, and point it out to our neighbours. So natural is it to admire what is strange rather than what is great.
5
6
The same thing holds in regard to comets. If one of these infrequent fires of unusual shape have made its appearance, everybody is eager to know what it is. Blind to all the other celestial bodies, each asks about the newcomer; one is not quite sure whether to admire or to fear it. Persons there are who seek to inspire terror by forecasting its grave import. And so people keep asking and wishing to know whether it is a portent or a star. But, by my honour, no one could embark on a more exalted study, or master a more useful branch of knowledge than that which treats of the nature of the stars and planets. Are they a concentration of flame as our vision avers, and as the very light that streams from them,91 and the heat that descends from them suggest? Or are their orbs not of flame, but, as it were, solid bodies of earth that glide through tracts of fire, and having no light of their own draw thence their brightness and heat? That is an opinion that has been held by great men who have believed the stars to be compact of hard material, and to be nourished by fire that is not their own. Flame by itself, they argue, would be dissipated and would have nothing to hold or to be held by. If it were merely massed and not attached to a solid body, the universe would assuredly long since have scattered it in its impetuous whirl.