text: Whatever is concrete to the sight or touch, Plato does not include among the things which he believes to be existent in the strict sense of the term. These things are the first that have to do with us: here we have all such things as men, cattle, and things. For they are in a state of flux, constantly diminishing or increasing. None of us is the same man in old age that he was in youth; nor the same on the morrow as on the day preceding. Our bodies are hurried along like flowing waters; every visible object accompanies time in its flight; of the things which we see, nothing is fixed. Even I myself, as I comment on this change, am changed myself. This is just what Heraclitus says: "We go down twice into the same river, and yet into a different river." For the stream still keeps the same name, but the water has already flowed past. Of course this is much more evident in rivers than in human beings. Still, we mortals are also carried past in no less speedy a course; and this prompts me to marvel at our madness in cleaving with great affection to such a fleeting thing as the body, and in fearing lest some day we may die, when every instant means the death of our previous condition. Will you not stop fearing lest that may happen once which really happens every day? So much for man, – a substance that flows away and falls, exposed to every influence; but the universe, too, immortal and enduring as it is, changes and never remains the same. For though it has within itself all that it has had, it has it in a different way from that in which it has had it; it keeps changing its arrangement.