Phaedo. And if it becomes
 smaller, 
 
 
 
 it
 must have been greater and then have become smaller? That is true, said he. And the weaker is generated from the stronger, and the
 slower from the quicker? Certainly. And the
 worse from the better and the more just from the more unjust? Of course. Then, said he, we have this fact sufficiently
 established, that all things are generated in this way, opposites from
 opposites? Certainly. Now then, is
 there between all these pairs of opposites what may be called 
 
 
 two kinds of generation, from one to the other and back
 again from the other to the first? Between a larger thing and a smaller thing
 there is increment and diminution and we call one increasing and the other
 decreasing, do we not? Yes, 
 said he. And similarly analyzing and
 combining, and cooling and heating, and all opposites in the same way. Even if
 we do not in every case have the words to express it, yet in fact is it not
 always inevitable that there is a process of generation from each to the
 other? Certainly, said
 he. 
 
 
 Well then, said Socrates,
 is there anything that is the opposite of living, as being awake is the
 opposite of sleeping? Certainly, said Cebes. What? Being
 dead, said he. Then these two are
 generated from each other, and as they are two, so the processes between them
 are two; is it not so? Of
 course. Now, said
 Socrates, I will tell about one of the two pairs of which I just spoke to
 you and its intermediate processes; and do you tell me about the other. I say
 one term is sleeping and the other is being awake, and being awake is generated
 from sleeping, and sleeping from being awake, 
 
 
 and the processes of generation are, in the latter case, falling asleep, and
 in the former, waking up. Do you agree, or not? Certainly. Now do you, said he, tell me in this way about life and
 death. Do you not say that living is the opposite of being
 dead? I do. And that they are generated one from the
 other? Yes. Now what is it which is generated from the
 living? The dead, said
 he. And what, said Socrates,
 from the dead? I can say only
 one thing—the living. From the
 dead, then, Cebes, the living, both things and persons, 
 
 
 are generated? Evidently, said he. Then, said Socrates, our souls exist in the other
 world. So it
 seems. And of the two processes
 of generation between these two, the one is plain to be seen; for surely dying
 is plain to be seen, is it not? Certainly, said he. Well
 then, said Socrates, what shall we do next? Shall we deny the
 opposite process, and shall nature be one-sided in this instance? Or must we
 grant that there is some process of generation the opposite of
 dying? Certainly we must, 
 said he. What is this process? 
 Coming to life again. Phaedo. Then, said Socrates, if there be such a
 thing as 
 
 
 
 coming to life again, this would be the process of generation from the dead to
 the living? Certainly. So by this
 method also we reach the conclusion that the living are generated from the dead,
 just as much as the dead from the living; and since this is the case, it seems
 to me to be a sufficient proof that the souls of the dead exist somewhere,
 whence they come back to life. I
 think, Socrates, that results necessarily from our previous
 admissions. Now here is another
 method, Cebes, to prove, as it seems to me, that we were right in making those
 admissions. 
 
 
 For if generation did not proceed
 from opposite to opposite and back again, going round, as it were in a circle,
 but always went forward in a straight line without turning back or curving,
 then, you know, in the end all things would have the same form and be acted upon
 in the same way and stop being generated at all. What do you mean? said he. It is not at all hard, said Socrates, to
 understand what I mean. For example, if the process of falling asleep existed,
 but not the opposite process of waking from sleep, 
 
 
 in the end, you know, that would make the sleeping Endymion
 mere nonsense; he would be nowhere, for everything else would be in the same
 state as he, sound asleep. Or if all thing were mixed together and never
 separated, the saying of Anaxagoras, all things are chaos, would soon come true.
 And in like manner, my dear Cebes, if all things that have life should die, and,
 when they had died, the dead should remain in that condition, is it not
 inevitable that at last all things would be dead 
 
 
 and nothing alive? For if the living were generated from any
 other things than from the dead, and the living were to die, is there any escape
 from the final result that all things would be swallowed up in
 death? I see none,
 Socrates, said Cebes. What you say seems to be perfectly
 true. I think, Cebes, 
 said he, it is absolutely so, and we are not deluded in making these
 admissions, but the return to life is an actual fact, and it is a fact that the
 living are generated from the dead and that the souls of the dead 
 
 
 exist. And besides, Cebes rejoined, if it is true, Socrates, as
 you are fond of saying, that our learning is nothing else than recollection,
 then this would be an additional argument that we must necessarily have learned
 in some previous time what we now remember.