The parts of the whole, I mean the parts which are contained in the Universe, must necessarily perish; perish, let us say, meaning change. Now, if it be a necessary evil for the parts to perish, it could not be well for the whole that its parts should tend to change and be constructed to perish in various ways. Did Nature then set out to injure her own constituent parts, making them so that they are liable to evil and of necessity fall into it; or did it escape her notice that this comes to pass? Both suppositions are incredible. And if, dropping the notion of Nature, one were merely to put it that things are constituted so, then how ridiculous at the same time to say that the parts of the Universe are constituted so as to change, and also to wonder and fret at change or dissolution, as if it were something against the course of Nature; especially as everything is dissolved into the elements out of which it arose. For there is either a scattering of the elements of which a thing was constructed, or a conversion of these, of the solid into earth, of the spiritual into air. So that these constituents are resumed into the system of the Universe, which either undergoes periodical conflagration, or is renewed by never-ending changes. And do not imagine that you had all your earthy and aerial matter from your birth. For the whole of this was an accession of yesterday or the day before, from your food and from the air you breathed. It is this accession which changes, and not what your mother bore. And granting that this recent accession may incline you more to what is individual in your constitution; yet, I think, it alters nothing of what has just been said.