KNOWLEDGE AND THE WORLD OF THE FORMS
This argument set the stage for the next, or the opening of
Plato's theory of knowledge as recollection and his theory of
forms. You should be able to see that up to this time he has
essentially unified the Hericlitean doctrines of opposites and
change and the Pythagorean doctrine of the transmigration of
souls. His next step, in a truly master stroke, is to further
unify the doctrines of Hericlitus and Parmenides to show that it
is possible for there to be both pure unchanging entities which
he calls the forms, and the constantly changing things of the
sensual world. Of course we can only have knowledge of the
unchanging therefore he must and does explain how we gain that
knowledge. By the same token if we cannot have knowledge of
constantly changing things then what of our experience of them
and from where do they gain their characteristics?
In the Phaedo Cebes brought up Socrates doctrine
that knowledge is simply recollection. If it is true, it also necessarily implies a
previous time in which we have learned that which we now recollect. "But this would be impossible," he said, " unless our
soul had been in some place before existing in the form of man; here then is another proof of the soul's immortality." One
proof, that he offered referred back the discussion in the Meno. If you put a question to a person in the right way, he will give
a true answer of himself, an answer he could not give unless there were knowledge and right reason already in him?
This problem is more important than it appears to be. Plato does
not need to get into detail about it because the doctrine of
recollection insures that the basic substance of everyone's
knowledge is the same and therefore people can exchange ideas
about things that all are acquainted with even though they may
have different opinions concerning them. When you get away from
the concept of platonic forms then you are faced with the problem
of consistent knowledge among people of differing backgrounds.
Aristotle's approach to mind required the existence of a class of
thinkable things which people could share in equally. The first
to offer an answer to this problem without resorting to something
approaching platonic forms was John Locke. He said that the
ideas in each man's mind were private, but men communicate using
words determined to express those ideas but which were developed
through arbitrary agreement. Men cannot share in each others
thoughts and must develop their own expressions of them by
communicating with others. This involves a very complicated
process and most modern philosophers still have failed to
understand exactly what Locke had in mind. However, we should
take a closer look at Plato's doctrine of recollection.
But if, said Socrates, you are still incredulous, Simmias, I
would ask you whether you may not agree with me when you look at
the matter in another way;--I mean, if you are still incredulous
as to whether knowledge is recollection?
Incredulous I am not, said Simmias; but I want to have this
doctrine of recollection brought to my own recollection, and,
from what Cebes has said, I am beginning to recollect and be
convinced: but I should still like to hear what you were going to
This is what I would say, he (Socrates) replied,―We should
agree, if I am not mistaken, that what a man recollects he must
have known at some previous time.
And what is the nature of this knowledge of recollection? I mean
to ask, whether a person who, having seen or heard or in any way
perceived anything, knows not only that, but has a conception of
something else which is the subject, not of the same but of some
other kind of knowledge, may not be fairly said to recollect that
of which he has the conception?
The doctrine of recollection does not require that one
experience exactly the same thing in order to be reminded of it.
It only requires that there be some connection between what is
experienced and what is recollected. You may be reminded of a
friend you once knew who liked to pitch when you played baseball
and later when you see someone using a similar wind-up routine,
you are reminded of him.
I mean what I may illustrate by the following instance: the
knowledge of a lyre is not the same as the knowledge of a man?
And yet what is the feeling of lovers when they recognize a lyre,
or a garment, or anything else which the beloved has been in the
habit of using? Do not they, from knowing the lyre, form in the
mind's eye an image of the youth to whom the lyre belongs? And
this is recollection. In like manner, anyone who sees Simmias
may remember Cebes (his brother); and there are endless examples
of the same thing.
And recollection is most commonly a process of recovering that
which has been already forgotten through time and inattention.
Well; and may you not also from seeing a picture of a horse or a
lyre remember a man? and from a picture of Simmias, you may be
led to remember Cebes?
Simmias and Cebes are brothers. Family resemblances are one sort
of trigger for recollection. It isn't even necessary that you
have ever met Simmias to have a recollection of Cebes when you
see his brother's picture.
Or you may also be led to the recollection of Simmias himself?
And in all these cases, the recollection may be derived from
things either like or unlike?
And when the recollection is derived from like things, then
another consideration is sure to arise, which is--whether the
likeness in any degree falls short or not of that which is
When we are reminded of something by something that is like it,
that likeness is never perfect. It is always a similarity, not
an identity. In fact we never experience two things that are
completely identical. There is always something, even though it
might be ever so slight, that makes one of them different from
And shall we proceed a step further, and affirm that there is
such a thing as equality, not of one piece of wood or stone with
another, but that, over and above this, there is an absolute
And do we know the nature of this absolute essence?
And whence did we attain our knowledge? Did we not see
equalities of material things, such as pieces of wood and stones,
and gather from them the idea of an equality which is different
from them? for you will acknowledge that there is a difference.
Or look at the matter in another way:--Do not the same pieces of
wood appear at one time equal and at another time unequal?
But are real equals ever unequal? or is the idea of equality the
same as of inequality?
Then these (so-called) equals are not the same with the idea of
And yet from these equals, although differing from the idea of
equality, you conceived and attained that idea?
But that makes no difference: whenever from seeing one thing you
conceived another, whether like or unlike, there must surely have
been an act of recollection?
But what would you say of equal portions of wood and stone or
other material equals? And what is the impression produced by
them? Are they equals in the same sense in which absolute
equality is equal? or do they fall short of this perfect equality
in a measure?
This problem occurs whenever we discuss absolute essences, or
perfection in general. Whenever we compare two things, saying
one is better or worse than another we are grading them on a
scale. But in life we never experience the limit of that scale.
We may say that two stones are equal but we seldom really mean it.
We mean that for the purpose in mind they are equivalent. If we
have never experienced perfect equality, or perfect beauty, or
the maximum of any other scale we might judge something by, then
how can we make comparisons.
And must we not allow, that when I or any one, looking at any
object, observes that the thing which he sees aims at being some
other thing, but falls short of, and cannot be, that other thing,
but is inferior, he who makes this observation must have had
previous knowledge of that to which the other, although similar,
And has not this been our own case in the matter of absolute
Then we must have known equality previous to the time when we
first saw the material equals, and reflected that all these
apparent equals strive to attain absolute equality, but fall
short of it?
And we recognize also that this absolute equality has only been
known and can only be known, through the medium of sight and
touch, or some other of the senses, which are all alike in this
From the senses then is derived the knowledge that all sensible
things aim at an absolute equality of which they fall short?
Then before we began to see or hear or perceive in any way, we
must have had a knowledge of absolute equality, or we could not
have referred to that standard the equals which are derived from
the senses?--for to that they all aspire, and of that they fall
Notice that this is an absolute. We have never experienced
anything that was perfectly equal, or for that matter perfect in
any way the mind can imagine.
And did we not see and hear and have the use of our other senses
as soon as we were born?
Then we must have acquired the knowledge of equality at some
That is to say, before we were born.
And if we acquired this knowledge before we were born and were
born having the use of it, then we also knew before we were born
and at the instant of birth not only the equal or the greater or
the less, but all other ideas; for we are not speaking only of
equality, but of beauty, justice, holiness, and of all which we
stamp with the name of essence in the dialectical process, both
when we ask and when we answer questions. Of all this we may
certainly affirm that we acquired the knowledge before birth.
But if after acquired, we have not forgotten what in each case we
acquired, then we must always have come into life having
knowledge, and shall always continue to know as long as life
lasts--for knowing is the acquiring and retaining of knowledge
and not forgetting. Is not forgetting, Simmias, just the losing
But if the knowledge which we acquired before birth was lost by
us at birth, and if afterwards by the use of the senses we
recovered what we previously knew, will not the process we call
learning be a recovering of the knowledge which was natural to
us, and may not this be rightly termed recollection?
Plato's theory of forms overcame some of the problems of both
Hericlitus and Parmenides through the application of Pythagorean
principles. Everything that can ever exist in the sensible world
has a perfect form in the world of the forms. However, what
exists in the sensible world is constantly changing. We can
never have knowledge of what is constantly changing because as
soon as we have knowledge of it, it changes to something else.
The forms, on the other hand, are permanent, they never change.
The world they exist in is the world of the eternal, the blessed
world where nothing ever changes. But Parmenides made the point
that if nothing changes then there can not be many things since
then there would necessarily be a separation between them and
this separation would be something that was not and it is
impossible for there to be and not to be at the same time.
Plato's world of forms does not have that kind of existence.
Because the world of the true forms does not have existence, it
has reality, it is a real world separate from the sensible. At
the same time, there can be many things in the sensible world
because they attain their existence by participating in the
perfect forms. In other words a single thing can participate in
both the beautiful and the ugly and thus have a range of beauty
in which to change. By the same token one can participate in
tallness by being taller than another and in shortness by being
shorter than a third person. However, as you can see, his theory
of forms is intimately bound up with his belief in the
immortality of the soul. Not only, as many moderns do, that the
soul exists after the death of the body, but as well that it
existed prior to the birth of the body. This naturally leads to
a special kind of doctrine of transmigration of souls where the
soul after death and before rebirth exists in this world of the
pure forms and gains all of its knowledge there. As we shall
see, these doctrines had a great deal to do with the development
of our western heritage.
In the Parmenides Plato depicted a young Socrates
basics of his theory of forms with an elder Parmenides. Its
purpose was to bring out the differences between his idea of the
forms and that of the Eleatic one. Plato's profound respect for
the Eleatic master is obvious throughout the dialogue. The
theory of the one being Plato felt was a major undertaking in
philosophy. But it is the transcendental reality of the soul as
the messenger between the world of the forms and the sensible
world that allowed Plato's approach to extend philosophy into the
moral world. Here are some of the arguments provided by
Parmenides against the Existence of the Forms.
1. Socrates theory of the forms separated the forms from the
things that shared in them. Therefore there exists a "similarity
itself" separate from the similarity that we recognize. This
entails an unlimited scope but Socrates was not ready to concede
this. When it came to things like beautiful and just he found no
problem, when it came to natural substances like fish he
hesitated, and when it came to worthless things like hair, clay
and dirt, he said that would be absurd. He shied away from it by
returning the conversation to things he was sure of, like the
moral and mathematical forms.
2. Parmenides said that if a form must be divisible then each
large thing will be large by having a portion of largeness
smaller than largeness itself. If the explanation of a man being
small is that he possess a part of smallness then the smallness
must be larger then the small itself and a man will be made
smaller by having something added.
3. The Third Man Argument is an extension of the one over many
argument. The one over many argument shows that for every
particular instance there must be one form. For every particular
flesh and blood man there is a form that is called men. But, to
account for the fact that the form of men correctly accounts for
the form of man there must be a third form of man. The argument
evolves into an infinite regress.
4. Parmenides said that if other things partake of the forms then
either each will be composed of thoughts and thus everything
would think, or else they are unthinking thoughts. Is it a
thought that thinks or a mind that forms it? When we think of
something existing outside us there are three factors involved: a
thinking mind, the concept which it forms, and the reality of
which it is a concept. But this only applies to the idea that
the forms are no more than concepts in the mind, an idea that
Plato rejected anyway.
5. The meaning of participation, Parmenides said, is that the
forms are the patterns fixed in the real world and particulars
resemble them and are fixed in the sensible world. He said that
this relationship must be reciprocal: as the particular resembles
the form so the form must resemble the particular. If two things
resemble each other they share the same character and that
character is another form. Thus for anything to resemble a form
would require a second form and that would lead to an infinite
regress. Plato did not answer this objection in the Parmenides.
He did provide an answer in the Cratylus where he stressed the
point that the forms are intelligible and thus could never be on
a par with the sensible.
6. Parmenides said that the forms, if they exist by themselves in
their own world, they must be related only to each other, not to
copies in the sensible world. At the same time things in the
sensible world, though named after the forms, could only be
related to each other. Since knowledge implies necessary
knowledge of something, then knowledge will have as its objects
varieties of reality. Therefore if we have no part of the forms
which are not in our world, then we can have no knowledge of the
forms and if any being has it, it must be a god and knowledge in
the world of the gods cannot be knowledge to us. What is missing
in Parmenides conception here is the relationship of the soul as
the epistemological link between the sensible world and the world
of the forms.
In the Theatetus Plato tackled those problems that
saw in the relationship between his theory of knowledge and his
theory of forms. These arguments were brought forward to prove
that everything that is conceivable can be put into one of two
categories, the sensible and the intelligible. The intelligible
is eternal, invisible and wholly real, the realm of being. The
sensible, including the entire world and everything in it, is the
realm of becoming.
The statement that Theatetus made was that knowledge is nothing
but perception, whoever knows something is perceiving it.
Socrates said that the statement was the same as Protagoras' most
famous statement, that man is the measure of all things, of what
is that it is, of what is not that it is not. What Plato said
this meant was that since everything that exists for the
individual is exactly what he perceives it to be then man's
perception is infallible. He can never be wrong. The sensible
world of Protagoras is a world of becoming. The sensations of
each person then become what they are individual to that person.
Why then should Protagoras be the teacher, Socrates asked? If
each person is the measure of his own wisdom then why should one
person's knowledge be better than another's. To attempt to
refute the notions and opinions of others would be sheer folly.
Plato's answer was that truth is real truth and the philosopher
is not merely amusing himself by giving oracles out of the shrine
of his book. The power which discerns not only in sensible
things but in all things those universal notions which we call
being and not-being is the mind. The mind has a power of its own
that contemplates the universals in all things.
Socrates used three axioms to dispute the Protogorean approach to
1. Nothing can become greater or less, either in number or
magnitude while remaining equal to itself.
2. Without addition or subtraction their is no increase or
diminution, only equality.
3. What was not before cannot be afterwards without having
Since Socrates, a grown adult is taller than Theatetus, a growing
young man, in time the boy will outgrown the man. In that way
Socrates would become something different, he would then be
smaller than Theatetus without anything having been subtracted
and without his having become something different. He showed
that they couldn't even be sure they were not dreaming.
Therefore, Protagoras as well as the idea that knowledge is
perception is incorrect, everything is in constant motion. Even
the act of sensation itself is motion. Not only that but a man
may have real knowledge and still not possess it. Knowledge may
very well be true opinion, but though man may have true opinion
he may mistake what it is he applies this opinion to. Thus a man
may be mistaken even though he has knowledge.
If knowledge is only of the universals that are explicit in
individual things, then knowledge can only be of non-material
things. As has been said before, one can not have knowledge of
individual things because they are under constant change and
knowledge can only be of what does not change. Plato is one of
the earliest idealists, that class of philosophers who believe
that what is real can only be understood through the mind. What
we experience, the changing world of the senses, is an illusion.
In the Sophist Plato used the ancient conflict
Titans and the Gods from Hesiod as a mechanism for describing the
battle between materialism and idealism. The dialogue is between
Theatetus and an Eleatic stranger. In these later dialogues
Socrates either becomes a minor character, or disappears
Stranger. There appears to be a sort of war of giants and gods going on amongst
them; they are fighting with one another about the nature of essence.
Theatetus. How is that?
Stranger. Some of them are dragging down all things from heaven and from the
unseen to the earth, and they literally grasp in their hands rocks and oaks; of these they lay hold,
and obstinately maintain that the things only which can be touched or handled have being or
essence, because they define being and body as one, and if any one else says that what is not a
body exists they altogether despise him, and will hear of nothing but body.
Theatetus. I have often met with such men, and terrible fellows they are.
Stranger. And that is the reason why their opponents cautiously defend themselves from above,
out of an unseen world, mightily contending that true essence consists of certain intelligible and
incorporeal forms; the bodies of the materialists, which by them are maintained to be the very
truth, they break up into little bits by their arguments, and affirm them to be, not essence, but
generation and motion. Between these two armies, Theatetus, there is always an endless
conflict raging concerning these matters.
Materialists, however, would freely admit to their being a mortal animal. They all admit that
their exists a body with a soul. Since one soul may be wise and another foolish, they both must
possess something, in this case wisdom and foolishness, that is immaterial. Therefore what they
possess must exist. If both the virtues and the souls in which they inhere exist, and all agree that
these are neither visible nor tangible, doesn't this imply that there are things which are
incorporeal and which nevertheless exist? Therefore can we not say that anything that has the
power to affect another is a thing which exists? Thus isn't it true that the materialists have come
a long way from believing that only that exists which can be squeezed in the hand. But from this
argument Plato said that we can derive the implication that the definition of being is connected
with power, not material.
This leads to his argument from the point of view of the idealists. These would distinguish
essence from generation. They would say that we participate in generation through the body and
in thought through the soul. But essence remains constant where generation varies. Thus being
is an active or a passive energy that arises out of the power that is produced by the elements
meeting with one another. But, the idealists would also argue that the power applies to both only
in becoming, and not in being. However, if we can say that the soul knows and the being is what
is known, then the known is acted upon by knowledge. If, then, all things that are thus acted on
then all things are in motion. Thus sameness of condition could never occur, there could be no
unchangeable. So there could be no knowledge, and mind could have no existence. Since we
must rile against anyone who would annihilate knowledge and reason, then we must say that all
is not in motion, we must have knowledge and we must have what is known. Of the movable
and the immovable, Plato said, "Give us both." With this statement Plato, often considered the
father of idealism, pointed out a feature often ignored in discussions of idealists, that is, that the
true idealist must account for those things considered real by the materialists as well as those
things the idealists hold as real. Two thousand years later the german philosopher Hegel would
put this idealist position in simple terms by stating that what is real does not exist and what
exists is not real.
For our purpose we need more than simply a description of Plato's ideas. We need a very
specific description of those elements of his thought that made them so important for the
development of western civilization and particularly western Christianity. For this we now turn
to the Timaeus, to Plato's description of God and
cosmology. This statement distills a great
deal of Platonic thought in one phrase.
What is that which always is and has no becoming; and what is
that which is always becoming and never is? That which is
apprehended by intelligence and reason is always in the same
state; but that which is conceived by opinion with the help of
sensation and without reason, is always in the process of
becoming and perishing and never really is.
As you can see, the Eleatic one has been transformed into the
world of the unchanging, of the pure forms. The sensual world,
Parmenides world of illusion has, in Plato's mature thought,
become the world of becoming. Timaeus then posed this question;
Was the world created or has it existed from eternity? This is
important for Plato's cosmology because it the world has existed
from eternity, that is if is eternal, it is part of the
unchanging world of the forms. If it created then it implied the
existence of a creator. It was to become an important question
for Christian thought also because much of early Christian
thought absorbed the Platonic view of the universe.
Timaeus' answer was quite simple.
The world is visible, tangible, has a body. Therefore it is
necessary that it was created and that it had a cause. But for
its pattern, the Creator necessarily looked to the unchangeable.
What he meant by the word "Creator" has been debated by scholars
for thousands of years. But the idea of a created universe, in
opposition to the traditional Greek idea of the eternal universe,
requires some entity which accomplished the creation.
Every one will see that He must have looked to the eternal; for
the world is the fairest of creations and He is the best of
causes. And having been created in this way, the world has been
framed in the likeness of that which is apprehended by reason and
mind and is unchangeable, and must therefore of necessity, if
this is admitted, be a copy of something.
This means that when we use words to describe the world and what
is in it, we need only use words that are probable. But, when we
are describing the eternal and unchangeable that the world was
patterned after, the words we use ought to be lasting and
unalterable. For, he said, "As being is to becoming, so is truth
Why. Timaeus went on, did the creator make this world of
He was good, and the good can never have any jealousy of
anything. And being free of jealousy, He desired that all things
should be as like himself as they could be.
The Creator began the process of creation by bringing order out
of chaos. Since He was creating the best and since no creature
devoid of intelligence was as fair He placed within those
creatures soul. "The world became a living creature truly
endowed with soul and intelligence by the providence of God." It
is a whole of which all animals both individually and in tribes
are portions. It contains in itself all intelligible beings.
Within this world God created one intelligent animal capable of
comprehending within itself all other animals.
There can be only one world because the world is a living entity
which comprehends all that is. For that which includes all other
intelligible creatures cannot have a second. That would require
another living being which could comprehend both. Such an
individual would necessarily resemble both and both would be
parts of this individual. The Creator necessarily made only one
world and one created heaven.
This is the final culmination of the centuries of Greek philosophy that led to
Plato. The Eleatic one has been turned into the Ideal world after which the world
created by God was patterned. This God is the God of Anaximenes
and Empedocles rolled into one. He is necessarily all good as
was the Zeus of Hesiod and Homer. But he is still an
abstraction, impersonal, a derivation of Pythagorean mysticism.
Even his description of the world soul as the intelligence of the
ideal world is purely abstract.
He took the three elements of the same, the other, and the
essence, and mingled them into one form. Compressing by force the
reluctant and unsociable nature of the other into the same. When
he had mingled them with the essence and out of three made one,
he again divided this whole into as many portions of the same,
the other, and the essence.
The division of the new whole which is a trinity of the same, the
other, and the essence, was done according to the Pythagorean
theorem and the diatonic scale. The motion of the other was
divided into the orbits of the seven planets. Once the soul was
formed he formed within it the corporeal universe.
The soul, interfused everywhere from the center to the
circumference of heaven, of which she also is the external
envelopment, herself turning in herself, began a divine beginning
of never-ceasing and rational life enduring throughout all time.
When reason is dealing with the sensible world there arises
opinions and beliefs. The sensible world is not real, it cannot
be known. Only when reason is dealing with the rational, the
real world, then intelligence and knowledge not only can, but
necessarily are perfected. Seeing the greatness of what he
created the Father sought to make all eternal. This was not
possible. Thus He created an eternal moving image of eternity .
This we call time. He constructed days and nights, past and
future all of which are created species of time. Note that the
moment that God created the past, he made the created world
eternal. Plato was without question an active participant in the
Athenian culture of his day. His ideas were brilliant
expressions of the period and culture in which he lived. They
remained a basic source of knowledge for another thousand years
despite a few hundred years of neglect under the Romans.
As we will discover, these ideas became mingled with the hotly
contested ideas of middle ages Christianity. They formed a
rational ground which, when it merged with the Nazarene Jews of
the Hellenistic period created a new religion that would sweep