Universals Are Real
Classic Philosophical Questions Part 6 - Metaphysics
Plato, from the Republic
Kem Stone - 21 December 2007
The editors have once again chosen Plato to represent a particular philosophical viewpoint in spite of the
weakness of his actual argument in favour of it.  To be fair, Plato’s theory of Forms, as presented in the
is the most famous example of the metaphysical claim that universals are real.  However, I still believe they would
have done better to offer a more contemporary defence of this claim, as the theory of Forms as presented in this
text is so full of holes that it is not the least bit convincing.

Plato begins by drawing the distinction between universals and particulars.  In his own words, the difference is
between “the multiplicity of things that we call good or beautiful or whatever it may be and, on the other hand,
Goodness itself or Beauty itself and so on” (337).  The metaphysical question that Plato asked over two thousand
years ago and which will probably never be answered is whether our world is made up only of particular objects
which we then classify into abstract, non-existent universals, or whether these particulars are what do not really
exist, and they are as Plato contends merely the images or “shadows” of the true objects, or Forms.

While this argument can probably never be definitively settled, there is no question that Plato’s reasoning is flawed
from the very beginning.  He wants to analogise thought to vision, and points out what he believes is a peculiar
quality of vision making it distinct from hearing in that “hearing and sound do not stand in need of any third thing,
without which the ear will not hear nor sound be heard, and I think the same is true of most, not to say all, of the
other senses” (337).  We now know of course that Plato is wrong about this—hearing does indeed require a third
thing in order to work: substance—but for now we will allow him this minor scientific error.  Plato only wants to
say that light, which is the third thing required in order for the eyes to see, is analogous to a third thing required in
order for the mind to be able to perceive intelligible objects.  This is the form of the Good, which for Plato is
analogous to the Sun, which is not vision itself but the cause of vision and can also be seen by the vision it causes.

For Plato, the Sun bears the same relation to visible objects as the Good bears to intelligible objects.  Without the
sun, the eye must strain to see visible objects, which appear very dim and faint and are hard to discern.  But when
the sun is shining, visible objects can be perceived quite clearly.  For Plato, then, when the gaze of the soul is fixed
upon something irradiated not by the Sun but by truth and reality, the soul gains a deeper understanding of that
object.  Yet when it remains focussed on the world of vision, this world of temporary objects that come into
existence and pass away, it can not have true knowledge but merely opinions and beliefs.  “This, then, which gives
to the objects of knowledge their truth and to him who knows them his power of knowing, is the Form or essential
nature of Goodness.  It is the cause of knowledge and truth” (338).

Plato then illustrates his concept in the form of a straight line divided into parts.  He first divides the line into two
unequal parts, the shorter representing the visible world that the Sun reigns over, and the larger representing the
intelligible world, reigned over by the Good.  Taking the shorter section he now divides this portion again into two
unequal parts (of the same ratio as the original) and calls the first and shortest (A) to represent the images or
reflections of actual objects and (B) to represent the actual objects in the world.

He then divides the part of the line representing intelligible objects into two sections, again with the same ratio.  “In
the first (C) the mind uses as images those actual things which themselves had images in the visible world; and it is
compelled to pursue its inquiry by starting from assumptions and travelling, not up to a principle, but down to a
conclusion.  In the second (D) the mind moves in the other direction, from an assumption up towards a principle
which is not hypothetical; and it makes no use of the images employed in the other section, but only of Forms, and
conducts its inquiry solely by their means” (339).  This is a bit confusing, as Plato’s interlocutor Glaucon points
out, and Plato explains by speaking of how students of geometry begin by postulating various numbers and figures
and take them as known, then form conclusions based on what is given.  They use images such as diagrams and
models to represent ideal forms such as Square and Circle while the images can never be the perfect Square or
Circle itself.  Most importantly they start with assumptions and never return to the first principle on which this
assumption is based, and their methods therefore belong in the (C) section of the line.

The (D) section, by contrast, does not treat its assumptions as first principles but as hypotheses, which are then
used to arrive at a first principle through pure dialectic reasoning, and finally down to a conclusion with complete
a priori) justification.  This is reasoning unaided by images, beginning exclusively with universal Forms, moving
through Forms and finally ending with Forms.  Glaucon expresses some understanding here, clarifying that while
the aforementioned students of geometry are taught to exercise thought in contemplating intelligible rather than
sensible objects they do not actually gain a true understanding of these objects because they rely on assumptions
which are taken for granted.

Plato has now provided us with an image to represent his understanding of the understanding, which is divided into
four states of mind: “
intelligence for the highest, thinking for the second, belief for the third, and for the last
imagining” (340).  There is a definite logic to this arrangement.  You begin with mere images of objects and have
no knowledge but merely imagination.  Seeing the reflection of a tree in water you are merely imagining a tree.  
When you deal with the actual objects you move beyond imagination and form actual beliefs.  Turning to the
actual tree you
believe you see a tree.  When dealing with the intelligible, you may start with the assumption that
the cylindrical shape of the tree trunk will conform to the formulas we have for a circle.  You are
thinking now
about a circle but are relying on the image of the tree’s trunk, an imperfect circle at best.  When you reach
intelligence you ignore the tree altogether, and starting with the idea of a circle move up to the very definition of a
circle (a figure on which all points are an equal distance from the centre) and then moving downward to all of the
conclusions that can be drawn from this (it’s circumference is equal to pi multiplied by twice its radius, etc.)

Plato then gives a much more vivid illustration of his idea in what is perhaps the most famous passage in all of
Plato’s works: The Allegory of the Cave.  He asks us to imagine a condition of men in which they spend their
entire lives underground in a cave, chained so that they cannot move nor turn their heads, facing a wall with a fire
burning somewhere behind them.  If persons behind them were to carry artificial objects which were then
projected as shadows onto the wall, they would no doubt form words to represent these objects, but would
believe that their words referred only to the shadows and not the objects themselves.

Should one of these prisoners be unchained and turned around, his eyes would at first be in great pain and he
would be too dazzled to see the correspondence between the objects and the shadows on the wall, nor as to the
connection between the shadows and the light from the fire.  If he were dragged further still outside of the cave
and into the sunlight, he would suffer even more pain and vexation, and his eyes would at first not be able to see
the objects he is now told are real.  His eyes would need to grow accustomed to the light before reaching this
understanding, which would end with his looking at the Sun and understanding it to be, in a way, the cause of
everything that he and his companions used to see.

Understanding that he now possessed far greater wisdom than his fellow prisoners, he would surely feel sorry for
them and perhaps wish to teach them of the true nature of the things they believed were real but were really only
shadows.  Yet should he descend back into the cave, his eyes would once again need to grow accustomed to the
darkness, and his fellow prisoners would laugh at him, saying his release had actually ruined his sight.  Should he
try to then explain the true nature of the images they saw, they would be unwilling to listen.  Should he try to break
their chains and free them, they would kill him.

This allegorical story can actually have a great number of meanings, but for Plato each element represents a
specific aspect of his theory of Forms.  “The prison dwelling corresponds to the region revealed to us through the
sense of sight, and the fire-light within it to the power of the Sun.  The ascent to see the things in the upper world
you may take as standing for the upward journey of the soul into the region of the intelligible” (342).  Most
important is the freed prisoner’s understanding of the Sun.  “In the world of knowledge, the last thing to be
perceived and with great difficulty is the essential Form of Goodness.  Once it is perceived, the conclusion must
follow that, for all things, this is the cause of whatever is right and good; in the visible world it gives birth to light
and to the lord of night, while it is itself sovereign in the intelligible world and the parent of intelligence and truth.  
Without having had a vision of this Form no one can act with wisdom, either in his own life or in matters of state”

Education, then, is not as some would imagine the implanting of knowledge into the mind as though putting sight
into blind eyes, but rather bringing out the quality inherent in any soul which allows it to see and contemplate the
true reality that surpasses this changing world of shadows.  A teacher does not merely speak truth and tell his
students to believe it, but shows the students what the truth really is, letting them see it on their own.  This is the art
of turning the soul around from facing the imperfect world of particulars to face the proper direction, the world of
universals, ruled by the “supreme splendour” of the Form of the Good.

Though I have always found the allegory of the cave to be a wonderful metaphor for the discovery of
philosophical truth, like everything else in this text it is merely an illustration rather than an argument.  The theory of
Forms suffers from many problems, and to go into all of them would actually be to venture outside the scope of
this text.  For instance, there is the “third man problem” which asks that if something is good because it is caused
by the Form of Goodness, is the Form of Goodness itself good?  If not, how can it be Goodness?  And if so,
mustn’t it be good because it is caused by another, higher Form of Goodness…a “third man”?  And if this is the
case, this “third man” Form of Goodness suffers from the same problem, which leads to an infinite regress.  Plato
does respond to this problem in other texts, but there is no hint of it here.

Here there are only two very objectionable ideas, the first of which is the sharp distinction Plato draws between
intelligence, thinking, belief, and imagining.  Although the divided line certainly seems logical, thought processes are
not as clear-cut as this illustration would suggest.  Can there be thinking without imagining?  Can there be
intelligence without belief?  Perhaps this is because thinking and intelligence are further up on the hierarchy than
imagining and belief, but the same objection holds if you reverse the terms.  You can not imagine without thinking,
nor can you form a belief without intelligence.  Perhaps I am not using the terms in the strict sense that Plato had
intended.  One may be able to imagine (picture a tree) without thinking (considering the dimension’s of the tree’s
trunk) and one may have a belief (that object is a tree) without intelligence (the trunk of the tree has a
circumference) but in reality all of these processes are so intermingled that placing them in a sharply divided
hierarchy such as Plato’s would today immediately be labelled as pseudoscience.  Note that I have not refuted
Plato’s claim, but I have shown that he requires an argument to justify this hypothetical structure and he has
offered none.

Finally, the idea of the Forms itself is just as vague and suspicious.  Something is good because it is caused by the
Form of Goodness.  What does this really mean?  How does this universal Form bestow Goodness upon the
images in the world of objects that come into being and pass away?  This idea becomes even more absurd when
we deal with something less abstract than Goodness.  How does this particular table relate to the universal Form
of Table?  What does the Form of Table look like and by what mechanism does it cause this particular object to
be a table?  Where is this realm of universals and how long has it existed?  Before the invention of the wheel, was
the universal form of Wheel still up there in “Plato’s Heaven” just waiting to be discovered?  Or did it suddenly
come into being once the first wheel was made?

I believe that the theory of Forms is a direct result of the nature of language.  We have words that correspond to a
large number of things, many of which have very few actual qualities in common with one another.  I use the word
“table” for both a flat, stone slab and a long, rectangular, elegantly designed piece of polished wood.  Both
objects may have as their primary function the placement of food on their surfaces, but beyond that they have
almost nothing in common.  Yet the same word is used in both cases, and this naturally leads to the idea that there
is some universal Table to which both of these seemingly very different objects are related.

The best example would actually be to return to the idea of Goodness.  Ethical relativism aside, we use the word
“good” to describe so many different things that without one unifying idea the word becomes meaningless.  What
is the real connection between my uttering the phrase, “I feel good” and telling someone that “sharing your food
with that hungry child was good”?  Without giving it any thought, there is an un-stated assumption that these ideas
are related, but I would contend that they are only related because we use the same
word in both cases.  The
word “good” just like the word “table” suggests the idea, often quite unexamined, that there exists somewhere in
reality a universal Good in which all good things share, or a universal Table to which all existing tables bear a

The definitive demonstration against the idea of universals would be a word like “liquid”.  This suggests the idea
that there is a universal form of Liquid to which all existing liquids are related.  Yet we may have water on the one
hand and liquid nitrogen on the other, which we know do not share any of the same type of molecules or even the
same type of atoms.  Their chemical compositions are 100% different and yet we would still use the word “liquid”
to describe both as though they were related in a universal sense.  But there is no universal Liquid—there are only
different chemical compounds arranged in different ways which make up different objects, be they solid, liquid, or
gas.  Every object in the universe is its own particular thing, unique from all other objects, and related to similar
objects only in the
mind of an observer, and not in an ethereal realm of universals.