Yes, he said.
And there are many other processes, such as division and composition, cooling and heating, which equally involve a passage into and out of one another. And this necessarily holds of all opposites, even though not always expressed in words — they are really generated out of one another, and there is a passing or process from one to the other of them?
Very true, he replied.
Well, and is there not an opposite of life, as sleep is the opposite of waking?
True, he said.
And what is it?
Death, he answered.
And these, if they are opposites, are generated the one from the other, and have there their two intermediate processes also?
Now, said Socrates, I will analyze one of the two pairs of opposites which I have mentioned to you, and also its intermediate processes, and you shall analyze the other to me. One of them I term sleep, the other waking. The state of sleep is opposed to the state of waking, and out of sleeping waking is generated, and out of waking, sleeping; and the process of generation is in the one case falling asleep, and in the other waking up. Do you agree?
I entirely agree.
Then, suppose that you analyze life and death to me in the same manner. Is not death opposed to life?
And they are generated one from the other?
What is generated from the living?
And what from the dead?
I can only say in answer — the living.
Then the living, whether things or persons, Cebes, are generated from the dead?
That is clear, he replied.
Then the inference is that our souls exist in the world below?
That is true.
And one of the two processes or generations is visible — for surely the act of dying is visible?
Surely, he said.
What then is to be the result? Shall we exclude the opposite process? And shall we suppose nature to walk on one leg only? Must we not rather assign to death some corresponding process of generation?
Certainly, he replied.
And what is that process?
Return to life.
And return to life, if there be such a thing, is the birth of the dead into the world of the living?
Then here is a new way by which we arrive at the conclusion that the living come from the dead, just as the dead come from the living; and this, if true, affords a most certain proof that the souls of the dead exist in some place out of which they come again.
Yes, Socrates, he said; the conclusion seems to flow necessarily out of our previous admissions.
And that these admissions were not unfair, Cebes, he said, may be shown, I think, as follows: If generation were in a straight line only, and there were no compensation or circle in nature, no turn or return of elements into their opposites, then you know that all things would at last have the same form and pass into the same state, and there would be no more generation of them.
What do you mean? he said.
A simple thing enough, which I will illustrate by the case of sleep, he replied. You know that if there were no alternation of sleeping and waking, the tale of the sleeping Endymion would in the end have no meaning, because all other things would be asleep, too, and he would not be distinguishable from the rest. Or if there were composition only, and no division of substances, then the chaos of Anaxagoras would come again. And in like manner, my dear Cebes, if all things which partook of life were to die, and after they were dead remained in the form of death, and did not come to life again, all would at last die, and nothing would be alive — what other result could there be? For if the living spring from any other things, and they too die, must not all things at last be swallowed up in death? (But compare Republic.)