Book 10
1.55
For in the case of changes of configuration within our experience the figure is supposed to be inherent when other qualities are stripped off, but the qualities are not supposed, like the shape which is left behind, to inhere in the subject of change, but to vanish altogether from the body. Thus, then, what is left behind is sufficient to account for the differences in composite bodies, since something at least must necessarily be left remaining and be immune from annihilation.
1.55
Again, you should not suppose that the atoms have any and every size, The opinion of Democritus.lest you be contradicted by facts; but differences of size must be admitted; for this addition renders the facts of feeling and sensation easier of explanation.
1.56
But to attribute any and every magnitude to the atoms does not help to explain the differences of quality in things; moreover, in that case atoms large enough to be seen ought to have reached us, which is never observed to occur; nor can we conceive how its occurrence should be possible, i.e. that an atom should become visible.Cf. Lucr. iv. 110-128, i. 599-627, ii. 478-521. The first of these passages states that the atom is far below the ken of our senses and much smaller than the things which our eyes begin to be able to see.
