Both statements are false. Let me take them in their order. Well, it 1 is asserted, is it, that all bodies are heavy that move more slowly? What! is the planet Saturn, which accomplishes its circuit most slowly of all the planets, heavy? It has, in fact, a proof of lightness in being higher than all the rest. But, you say, it takes a wider sweep, and does not go more slowly than the others, but only a longer distance. Let me suggest that I can make the same statement of the comets; even if their course is more sluggish, they have farther to go. But it is a falsehood to assert that they move more slowly. For this 2 last comet traversed within six months half the span of heaven; the previous one withdrew from sight in a shorter period. But again, it is urged, on account of their weight, they are borne down lower. Well, in the first place, a comet is not borne down, but round. In the second, this recent one began its motion in the north, and passing by way of the west, reached the southern quarters, and was elevating its orbit when it faded from sight. That other one, in Claudius’ reign, also 3 first appeared in the north, and continued without intermission to rise straight up to a higher elevation until it disappeared. Such are the matters relating to comets which have had weight with others and with myself. Whether they are true or not, those who attain knowledge of the truth must decide. We are permitted only to conjecture and grope in the dark, with no assurance of discovery, and yet not without hope. XXX