The Phaedo is the scene of the death of Socrates. Finally the ship from Delos has arrived and it is time for Socrates to drink
the hemlock. At this point, with his friends about him, he
discussed the interrelated problems of the soul and of knowledge.
For the Greeks knowledge could only be of what could not be
different from what it is. Thus knowledge can be only of
unchanging things. Hericlitus, on the other hand, showed that
everything is constantly changing. Thus Plato was forced to face
what Aristotle called his "Hericlitean problem", that is how can
we have knowledge of anything when everything is constantly
changing. Yet we cannot deny Hericlitus' pronunciation in spite
of the fact that we deal with it every day. Suppose for example
that you were a close friend of John Smith when you both were
young and then lose contact for a few decades. When you meet
again he is still John Smith yet he has changed drastically. How
can you say that you have knowledge of him? But if knowledge is
only of the unchanging, then it is an Eleatic as well as a
Hericlitean problem because it relegates all of those things that
we deal with in our normal lives to the unreal. Hericlitus'
solution, that the logos, what is constant beneath the changing
things of our sensual existence tells us little or nothing and
Parmenides solution that it is simply unreal is equally
mysterious, for we must and do interact with these things that
are under constant flux. Knowledge, in the Greek sense of what
is unchanging, must then be eternal and what is eternal is
divine. This means that if a man is to have knowledge, there
must be a part of him that is divine. For Plato this was the
soul. And at the same time, though we may deny reality to those
things that are in constant flux, we must still deal with them in
our everyday life. Plato's solution to this problem was the
concept of participation. But he explains this much better than
I in the Phaedo. The questions he asked to bring these ideas out
dealt with the existence of such things as absolute justice, or
absolute beauty. "Did you ever behold any of them with your
eyes?" he asked.
Or did you ever reach them with any other bodily sense?―and I speak not of these alone, but of absolute greatness, and health, and strength, and of the essence or true nature of everything. Has the reality of them ever been perceived by you through the bodily organs? or rather, is not the nearest approach to knowledge of their several natures made by him who so orders his intellectual vision as to have the most exact conception of the essence of each thing which he considers?
In a world that is rational yet is filled with the irrational,
the irrational must have a different kind of being. Reality in a
rational world is quintessentially understandable, it can by
definition become known. But the changing, the irrational, the
unexpected, the world of the passions and the senses cannot be
real. For if it was then the world would not be knowable, it
would not be rational. Since it is the mind and the mind alone
that can recognize the rational that lies behind the unreal
sensual world, it is only through the mind that man can know the
And he attains to the purest knowledge of them who goes to each with the mind alone, not introducing or intruding in the act of thought sight or any other sense together with reason, but with the very light of the mind in her own clearness searches into the very truth of each; he who has got rid, as far as he can, of eyes and ears and, so to speak, of the whole body, these being in his opinion distracting elements which when they infect the soul hinder her from acquiring truth and knowledge―who, if not he, is likely to attain to the knowledge of true being?
But there is a path to such knowledge. That is the path of
philosophy. The path of the search for true wisdom requires a
discipline which will avoid completely all of the evils brought
on by the body.
And when real philosophers consider all these things, will they not be led to make a reflection which they will express in words
like the following? 'Have we not found,' they will say, 'a path
of thought which seems to bring us and our argument to the conclusion, that while we are in the body, and while the soul is
infected with the evils of the body, our desire will not be satisfied? And our desire is of the truth. For the body is the source of endless trouble to us by reason of the mere requirement of food; and is liable also to diseases which overtake and impede
us in the search after true being: it fills us full of loves, and
lusts, and fears, and fancies of all kinds, and endless foolery,
and in fact, as men say, takes away from us the power of thinking
The body is part of the unreal world of the changing, the
illusive. Knowledge must be of the unchanging, the divine. As
such it can only be apprehended by the mind which alone can touch
the divine through the faculty of reasoning. To be quit of the
body means to have the fetters removed from the mind.
It has been proved to us by experience that if we would have
pure knowledge of anything we must be quit of the body―the soul
in herself must behold things in themselves: and then we shall
attain the wisdom which we desire, and of which we say that we
are lovers; not while we live, but after death; for if while in
company with the body, the soul cannot have pure knowledge, one
of two things follows―either knowledge is not to be attained at
all, or, if at all, after death. For then, and not till then,
the soul will be parted from the body and exist in herself alone.
In this present life, I reckon that we make the nearest approach
to knowledge when we have the least possible intercourse or
communion with the body, and are not surfeited with the bodily
nature, but keep ourselves pure until the hour when God himself
is pleased to release us. And thus having got rid of the
foolishness of the body we shall be pure and hold converse with
the pure, and know of ourselves the clear light everywhere, which
is no other than the light of truth.' For the impure are not
permitted to approach the pure. These are the sort of words, Simmias, which the true lovers of knowledge cannot help saying to
one another and thinking.
The idea of transmigration of souls dates back to Orphic and
Pythagorean doctrine. Is that ancient belief enough? Not for
Socrates. There must be some proof other than the beliefs of the
ancients. As a philosopher he must have some reasoned argument
that the souls of men are immortal and that after death they are
reborn into a another body. Some argument that can be known
through reason alone.
Suppose we consider the question whether the souls of men after
death are or are not in the world below. There comes into my
mind an ancient doctrine which affirms that they go from hence
into the other world, and returning hither, are born again from
the dead. Now if it be true that the living come from the dead,
then our souls must exist in the other world, for if not, how
could they have been born again? And this would be conclusive,
if there were any real evidence that the living are only born
from the dead; but if this is not so, then other arguments will
have to be adduced.
Remember that by real arguments he means arguments that can be
settled through reasoning. In our discussion of the presocratics, that in order for all things to change from one to
another there had to be both an underlying substrata out of which
everything came to be. There also had to be a source of eternal
motion through which the interplay of opposites could occur which
would result in the sensual world which we experience. This was
the fundamental cause of existence for Heraclitus, Anaximander,
Anaximenes, indeed most of the presocratic philosophers. The
engine of change within the underlying substrata for all of them
was the conflict of opposites in the eternally moving chaos.
Then let us consider the whole question, not in relation to man
only, but in relation to animals generally, and to plants, and to
everything of which there is generation, and the proof will be
easier. Are not all things which have opposites generated out of
their opposites? I mean such things as good and evil, just and
unjust―and there are innumerable other opposites which are
generated out of opposites. And I want to show that in all
opposites there is of necessity a similar alternation; I mean to
say, for example, that anything which becomes greater must
becomes greater after being less. And that which becomes less
must have been once greater and then have become less.
And the weaker is generated from the stronger, and the swifter
from the slower.
We need not go into detail concerning this exercise in
Hericlitean doctrine to realize where Socrates is headed, that
life and death are opposites and that one is generated from the
other. And, if the living are generated from the dead then souls
must exist in the world below. Of the two processes or
generations one is visible--for the act of dying is visible.
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?" And what process would that be? why, return to
This argument, as you can see, relates only to necessary
logical connections between things that cannot not be. So he
And return to life, if there be such a thing, is the birth of the
dead into 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
He thus offered further proof to back up these claims. This proof is
particularly meaningful when we think, as the Greeks did, that
the world is eternal and has always been just as it is. "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 it is obvious that all things would in time have the same form and pass into the same state, and there would be no more generation of them." If there were no alternation of sleep and waking, all things would be asleep. If there were composition only, and no division of substances, then the chaos of Anaxagorus would come again. "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?"