Book 10
1.40
Again [he repeats this in the First Book and in Books XIV. and XV. of the work On Nature and in the Larger Epitome], of bodies some are composite, others the elements of which these composite bodies are made.
1.41
These elements are indivisible and unchangeable, and necessarily so, if things are not all to be destroyed and pass into non-existence, but are to be strong enough to endure when the composite bodies are broken up, because they possess a solid nature and are incapable of being anywhere or anyhow dissolved.Cf.§ 54. It follows that the first beginnings must be indivisible, corporeal entities.
1.41
Again, the sum of things is infinite. For what is finite has an extremity, and the extremity of anything is discerned only by comparison with something else. (Now the sum of things is not discerned by comparison with anything else:The missing premiss is supplied by Cicero, De div. ii. 103 at quod omne est, id non cernitur ex alio extrinsecus. Cf. Lucr. i. 960.) hence, since it has no extremity, it has no limit; and, since it has no limit, it must be unlimited or infinite.
1.41
Moreover, the sum of things is unlimited both by reason of the multitude of the atoms and the extent of the void.
1.42
For if the void were infinite and bodies finite, the bodies would not have stayed anywhere but would have been dispersed in their course through the infinite void, not having any supports or counter-checks to send them back on their upward rebound. Again, if the void were finite, the infinity of bodies would not have anywhere to be.
1.42
Furthermore, the atoms, which have no void in them—out of which composite bodies arise and into which they are dissolved—vary indefinitely in their shapes; for so many varieties of things as we see could never have arisen out of a recurrence of a definite number of the same shapes. The like atoms of each shape are absolutely infinite; but the variety of shapes, though indefinitely large, is not absolutely infinite.
