heavy, and tending downwards; others dry and earthy, and therefore still heavy; but others fiery, and therefore always pushing upwards; others cold and inert, and always remaining in the middle. Since then some, as being fiery, always tend upward, and others, as being moist and dry, always downwards, and others keep a middle and unequal course, how could they meet together and form one body? For if any one throw down from a height small pieces of straw, for example, and pieces of lead of the same size, will the light straws be able to keep up with the pieces of lead, though they be equal in size? Nay; the heavier reach the bottom far more quickly. So also atoms, though they be equal in size, yet, being unequal in weight, the lighter will never be able to keep pace with the heavier; but if they cannot keep pace, certainly neither can they be mixed or form one body.
Chap. xviii.—The concourse of atoms could not make the world.
"Then, in the next place, if they are ceaselessly borne about, and always coming, and being added to things whose measure is already complete, how can the universe stand, when new weights are always being heaped upon so vast weights? And this also I ask: If this expanse of heaven which we see was constructed by the gradual concurrence of atoms, how did it not collapse while it was in construction, if indeed the yawning top of the structure was not propped and bound by any stays? For as those who build circular domes, unless they bind the fastening of the central top, the whole falls at once; so also the circle of the world, which we see to be brought together in so graceful a form, if it was not made at once, and under the influence of a single forth-putting of divine energy by the power of a Creator, but by atoms gradually concurring and constructing it, not as reason demanded, but as a fortuitous issue befell, how did it not fall down and crumble to pieces before it could be brought together and fastened? And further, I ask this: What is the pavement on which the foundations of such an immense mass are laid? And again, what you call the pavement, on what
