PLATO
None of the predecessors of Plato had constructed a system of
philosophy. What they had produced, and in great abundance, were
isolated philosophical ideas, theories, hints, and suggestions. Plato
was the first person in the history of the world to produce a great
all-embracing system of philosophy, which has its ramifications in all
departments of thought and reality. In doing this, Plato laid all
previous thought under contribution. He gathered the entire harvest of
Greek philosophy. All that was best in the Pythagoreans, the Eleatics,
Heracleitus, and Socrates, reappears, transfigured in the system of
Plato. But it is not to be imagined, on this account, that Plato was a
mere eclectic, or a plagiarist, who took the best thoughts of others,
and worked them into some sort of a patch-work philosophy of his own.
He was, on the contrary, in the highest degree an original thinker.
But like all great systems of thought, that of Plato grows out of the
thought of previous thinkers. He does indeed appropriate the ideas of
Heracleitus, Parmenides, and Socrates. But he does not leave them as
he finds them. He takes them as the germs of a new development. They
are the foundations, below ground, upon which he builds the palace of
philosophy. In his hands, all previous thought becomes {165}
transfigured under the light of a new and original principle.
1. Life and Writings.
The exact date of the birth of Plato is a matter of doubt. But the
date usually given, 429-7 B.C. cannot be far wrong. He came of an
aristocratic Athenian family, and was possessed of sufficient wealth
to enable him to command that leisure which was essential for a life
devoted to philosophy. His youth coincided with the most disastrous
period of Athenian history. After a bitter struggle, which lasted over
a quarter of a century, the Peloponnesian war ended in the complete
downfall of Athens as a political power. And the internal affairs of
the State were in no less confusion than the external. Here, as
elsewhere, a triumphant democracy had developed into mob-rule. Then at
the close of the Peloponnesian war, the aristocratic party again came
into power with the Thirty Tyrants, among whom were some of Plato's
own relatives. But the aristocratic party, so far from improving
affairs, plunged at once into a reign of bloodshed, terror, and
oppression. These facts have an important bearing upon the history of
Plato's life. If he ever possessed any desire to adopt a political
career, the actual condition of Athenian affairs must have quenched
it. An aristocrat, both in thought and by birth, he could not
accommodate himself to the rule of the mob. And if he ever imagined
that the return of the aristocracy to power would improve matters, he
must have been bitterly disillusioned by the proceedings of the Thirty
Tyrants. Disgusted alike with the democracy and the aristocracy he
seems to have retired into seclusion. He never once, throughout his
long life, appeared as a {166} speaker in the popular assembly. He
regarded the Athenian constitution as past help.
Not much is known of the philosopher's youth. He composed poems. He
was given the best education that an Athenian citizen of those days
could obtain. His teacher, Cratylus, was a follower of Heracleitus,
and Plato no doubt learned from him the doctrines of that philosopher.
It is improbable that he allowed himself to remain unacquainted with
the disputations of the Sophists, many of whom were his own
contemporaries. He probably read the book of Anaxagoras, which was
easily obtainable in Athens at the time. But on all these points we
have no certain information. What we do know is that the decisive
event in his youth, and indeed in his life, was his association with
Socrates.
For the last eight years of the life of Socrates, Plato was his friend
and his faithful disciple. The teaching and personality of the master
constituted the supreme intellectual impulse of his life, and the
inspiration of his entire thought. And the devotion and esteem which
he felt for Socrates, so far from waning as the years went by, seem,
on the contrary, to have grown continually stronger. For it is
precisely in the latest dialogues of his long life that some of the
most charming and admiring portraits of Socrates are to be found.
Socrates became for him the pattern and exemplar of the true
philosopher.
After the death of Socrates a second period opens in the life of
Plato, the period of his travels. He migrated first to Megara, where
his friend and fellow-disciple Euclid was then founding the Megaric
school. The Megaric philosophy was a combination of the thought of
Socrates with that of the Eleatics. And it was no doubt here, at {167}
Megara, under the influence of Euclid, that Plato formed his deeper
acquaintance with the teaching of Parmenides, which exercised an
all-important influence upon his own philosophy. From Megara he
travelled to Cyrene, Egypt, Italy, and Sicily. In Italy he came in
contact with the Pythagoreans. And to the effects of this journey may
be attributed the strong Pythagorean elements which permeate his
thought.
In Sicily he attended the court of Dionysius the Elder, tyrant of
Syracuse. But here his conduct seems to have given grave offence.
Dionysius was so angered by his moralizings and philosophical
diatribes that he put Plato up to auction in the slave market. Plato
narrowly escaped the fate of slavery, but was ransomed by Anniceris,
the Cyrenaic. He then returned to Athens, his travels having occupied
a period of about ten years.
With the return of Plato to Athens we enter upon the third and last
period of his life. With the exception of two journeys to be mentioned
shortly, he never again left Athens. He now appeared for the first
time as a professional teacher and philosopher. He chose for the scene
of his activities a gymnasium, called the Academy. Here he gradually
collected round him a circle of pupils and disciples. For the rest of
his life, a period of about forty years, he occupied himself in
literary activity, and in the management of the school which he had
founded. His manner of life was in strong contrast to that of
Socrates. Only in one respect did he resemble his master. He took no
fees for his teaching. Otherwise the lives of the two great men bear
no resemblance to each other. Socrates had gone out into the highways
and byways in search of wisdom. He had wrangled in {168} the
market-place with all comers. Plato withdrew himself into the
seclusion of a school, protected from the hubbub of the world by a
ring of faithful disciples. It was not to be expected that a man of
Plato's refinement, culture, and aristocratic feelings, should
appreciate, as Socrates, the man of the people, had done, the
rough-and-tumble life of the Athenian market-place. Nor was it
desirable for the advancement of philosophy that it should be so. The
Socratic philosophy had suffered from the Socratic manner of life. It
was unmethodical and inchoate. Systematic thought is not born of
disputes at the street corner. For the development of a great
world-system, such as that of Plato, laborious study and quiet
seclusion were essential.
This period of Plato's mastership was broken only by two journeys to
Sicily, both undertaken with political objects. Plato knew well that
the perfect State, as depicted in his "Republic," was not capable of
realization in the Greece of his own time. Nevertheless, he took his
political philosophy very seriously. Though the perfect republic was
an unattainable ideal, yet, he thought, any real reform of the State
must at least proceed in the direction of that ideal. One of the
essential principles of the "Republic" was that the rulers must also
be philosophers. Not till philosopher and ruler were combined in one
and the same person could the State be governed upon true principles.
Now, in the year 368 B.C., Dionysius the Elder died, and Dionysius the
younger became tyrant of Syracuse. Dionysius despatched an invitation
to Plato to attend his court and give him the benefit of his advice.
Here was an opportunity to experiment. Plato could train and educate a
{169} philosopher-king. He accepted the invitation. But the expedition
ended disastrously. Dionysius received him with enthusiasm, and
interested himself in the philosophical discourses of his teacher. But
he was young, impetuous, hot-headed, and without genuine philosophic
bent. His first interest gave place to weariness and irritation. Plato
left Syracuse a disappointed man; and returned to Athens.
Nevertheless, after the lapse of a few years, Dionysius again invited
him to Syracuse, and again he accepted the invitation. But the second
journey ended in disaster like the first, and Plato was even in danger
of his life, but was rescued by the intervention of the Pythagoreans.
He returned to Athens in his seventieth year, and lived till his death
in the seclusion of his school, never again attempting to intervene in
practical politics.
For more than another decade he dwelt and taught in Athens. His life
was serene, quiet, and happy. He died peacefully at the age of
eighty-two.
Plato's writings take the form of dialogues. In the majority of these,
the chief part is taken by Socrates, into whose mouth Plato puts the
exposition of his own philosophy. In a few, as for example the
"Parmenides," other speakers enunciate the Platonic teaching, but even
in these Socrates always plays an important _role_. Plato was not only
a philosopher, but a consummate literary artist. The dialogues are
genuinely dramatic, enlivened by incident, humour, and life-like
characterization. Not only is the portrait of Socrates drawn with
loving affection, but even the minor characters are flesh and blood.
A most important element of Plato's style is his use of myths. He does
not always explain his meaning in {170} the form of direct scientific
exposition. He frequently teaches by allegories, fables, and stories,
all of which may be included under the one general appellation of
Platonic myths. These are often of great literary beauty, but in spite
of this they involve grave disadvantages. Plato slips so easily from
scientific exposition into myth, that it is often no easy matter to
decide whether his statements are meant literally or allegorically.
Moreover, the myths usually signify a defect in his thought itself.
The fact is that the combination of poet and philosopher in one man is
an exceedingly dangerous combination. I have explained before that the
object of philosophy is, not merely to feel the truth, as the poet and
mystic feel it, but intellectually to comprehend it, not merely to
give us a series of pictures and metaphors, but a reasoned explanation
of things upon scientific principles. When a man, who is at once a
poet and a philosopher, cannot rationally explain a thing, it is a
terrible temptation to him to substitute poetic metaphors for the
explanation which is lacking. We saw, for example, that the writers of
the Upanishads, who believed that the whole world issues forth from
the one, absolute, imperishable, being, which they called Brahman,
being unable to explain why the One thus differentiates itself into
the many, took refuge in metaphors. As the sparks from the substantial
fire, so, they say, do all finite beings issue forth from the One. But
this explains nothing, and the aim of the philosopher is not thus
vaguely to feel, but rationally to understand. Now this is not merely
my view of the functions of philosophy. It is emphatically Plato's own
view. In fact Plato was the originator of it. He is perpetually
insisting that {171} nothing save full rational comprehension deserves
the names of knowledge and philosophy. No writer has ever used such
contemptuous language as Plato used of the mere mystic and poet, who
says wise and beautiful things, without in the least understanding why
they are wise and beautiful. No man has formed such a low estimate of
the functions of the poet and mystic. Plato is, in theory at least,
the prince of rationalists and intellectualists. In practice, however,
he must be convicted of the very fault he so severely censured in
others. This, in fact, is the explanation of most of the Platonic
myths. Wherever Plato is unable to explain anything, he covers up the
gap in his system with a myth. This is particularly noticeable, for
example, in the "Timaeus." Plato having, in other dialogues, developed
his theory of the nature of the ultimate reality, arrives, in the
"Timaeus," at the problem how the actual world is to be explained from
that ultimate reality. At this point, as we shall see, Plato's system
breaks down. His account of the absolute reality is defective, and in
consequence, it affords no principle whereby the actual universe can
be explained. In the "Timaeus," therefore, instead of a reasoned
explanation, he gives us a series of wholly fanciful myths about the
origin of the world. Wherever we find myths in Plato's dialogues, we
may suspect that we have arrived at one of the weak points of the
system.
If we are to study Plato intelligently, it is essential that we should
cease to regard the dialogues as if they were all produced _en bloc_
from a single phase of their author's mind. His literary activity
extended over a period of not less than fifty years. During that time,
he did not stand still. His thought, and his mode of {172} expression,
were constantly developing. If we are to understand Plato, we must
obtain some clue to enable us to trace this development. And this
means that we must know something of the order in which the dialogues
were written. Unfortunately, however, they have not come down to us
dated and numbered. It is a matter of scholarship and criticism to
deduce the period at which any dialogue was written from internal
evidences. Many minor points are still undecided, as well as a few
questions of importance, such as the date of the "Phaedrus," [Footnote
11] which some critics place quite early and some very late in Plato's
life. Neglecting these points, however, we may say in general that
unanimity has been reached, and that we now know enough to be able to
trace the main lines of development.
[Footnote 11: The same remark applies to the "Symposium," the
"Republic," and the "Theaetetus."]
The dialogues fall into three main groups, which correspond roughly to
the three periods of Plato's life. Those of the earliest group were
written about the time of the death of Socrates, and before the
author's journey to Megara. Some of them may have been written before
the death of Socrates. This group includes the "Hippias Minor," the
"Lysis," the "Charmides," the "Laches," the "Euthyphro," the
"Apology," the "Crito," and the "Protagoras." The "Protagoras" is the
longest, the most complex in thought, and the most developed. It is
probably the latest, and forms the bridge to the second group.
All these early dialogues are short and simple, and are still, as
regards their thought, entirely under the influence of Socrates. Plato
has not as yet developed {173} any philosophy of his own. He propounds
the philosophy of Socrates almost unaltered. Even so, however, he is
no mere plagiarist. There are throughout these dialogues evidences of
freshness and originality, but these qualities exhibit themselves
rather in the literary form than in the philosophical substance. We
find here all the familiar Socratic propositions, that virtue is
knowledge, is one, is teachable; that all men seek the good, but that
men differ as to what the good is; that a man who does wrong
deliberately is better than a man who does it unintentionally; and so
on. Moreover, just as Socrates had occupied himself in attempting to
fix the concepts of the virtues, asking "what is prudence?", "what is
temperance?", and the like, so in many of these dialogues Plato
pursues similar inquiries. The "Lysis" discusses the concept of
friendship, the "Charmides" of temperance, the "Laches" of bravery. On
the whole, the philosophical substance of these early writings is thin
and meagre. There is a preponderance of incident and much biographical
detail regarding Socrates. There is more art than matter.
Consequently, from a purely literary point of view, these are among
the most charming of Plato's dialogues, and many of them, such as the
"Apology" and the "Crito," are especially popular with those who care
for Plato rather as an artist than as a philosopher.
The second group of dialogues is generally connected with the period
of Plato's travels. In addition to the influence of Socrates, we have
now the influence of the Eleatics, which naturally connects these
dialogues with the period of the philosopher's sojourn at Megara. But
it is in these dialogues, too, that Plato for the first time {174}
develops his own special philosophical thesis. This is in fact his
great constructive period. The central and governing principle of his
philosophy is the theory of Ideas. All else hinges on this, and is
dominated by this. In a sense, his whole philosophy is nothing but the
theory of Ideas and what depends upon it. It is in this second period
that the theory of Ideas is founded and developed, and its
relationship to the Eleatic philosophy of Being discussed. We have
here the spectacle of Plato's most original thoughts in the pangs of
childbirth. He is now at grips with the central problems of
philosophy. He is intent upon the thought itself, and cares little for
the ornaments of style. He is struggling to find expression for ideas
newly-formed in his mind, of which he is not yet completely master,
and which he cannot manipulate with ease. Consequently, the literary
graces of the first period recede into the background. There is little
incident, and no humour. There is nothing but close reasoning, hard
and laborious discussion.
The twin dialogues, "Gorgias" and "Theaetetus" are probably the
earliest of this group. They result in nothing very definite, and are
chiefly negative in character. Plato is here engaged merely in a
preparatory clearing of the ground. The "Gorgias" discusses and
refutes the Sophistic identification of virtue and pleasure, and
attempts to show, as against it, that the good must be something
objectively existent, and independent of the pleasure of the
individual. The "Theaetetus," similarly, shows that truth is not, as
the Sophists thought, merely the subjective impression of the
individual, but is something objectively true in itself. The other
{175} dialogues of the group are the "Sophist," the "Statesman," and
the "Parmenides." The "Sophist" discusses Being and not-being, and
their relationship to the theory of Ideas. The "Parmenides" inquires
whether the absolute reality is to be regarded, in the manner of the
Eleatics, as an abstract One. It gives us, therefore, Plato's
conception of the relation of his own philosophy to Eleaticism.
The dialogues of the third group are the work of Plato's maturity. He
has now completely mastered his thought, and turns it with ease in all
directions. Hence the style returns to the lucidity and purity of the
first period. If the first period was marked chiefly by literary
grace, the second by depth of thought, the third period combines both.
The perfect substance is now moulded in the perfect form. But a
peculiarity of all the dialogues of this period is that they take it
for granted that the theory of Ideas is already established and
familiar to the reader. They proceed to apply it to all departments of
thought. The second period was concerned with the formulation and
proof of the theory of Ideas, the third period undertakes its
systematic application. Thus the "Symposium," which has for its
subject the metaphysic of love, attempts to connect man's feeling for
beauty with the intellectual knowledge of the Ideas. The "Philebus"
applies the theory of Ideas to the sphere of ethics, the "Timaeus" to
the sphere of physics, and the "Republic" to the sphere of politics.
The "Phaedo" founds the doctrine of the immortality of the soul upon
the theory of Ideas. The "Phaedrus" is probably to be grouped with the
"Symposium." The beauty, grace, and lucidity of the style, and the
fact that it assumes throughout that {176} the theory of Ideas is a
thing established, lead us to the belief that it belongs to the period
of Plato's maturity. Zeller's theory that it was written at the
beginning of the second period, and is then offered to the reader as a
sort of sweetmeat to induce him to enter upon the laborious task of
reading the "Sophist," the "Statesman," and the "Parmenides," seems to
be far-fetched and unnecessary. [Footnote 12]
[Footnote 12: Zeller's _Plato and the Older Academy_, chap. iii.]
If the second is the great constructive period of Plato's life, the
third may be described as his systematic and synthetic period. Every
part of his philosophy is here linked up with every other part. All
the details of the system are seen to flow from the one central
principle of his thought, the theory of Ideas. Every sphere of
knowledge and being is in turn exhibited in the light of that
principle, is permeated and penetrated by it.
The plan for expounding Plato which first suggests itself is to go
through the dialogues, one by one, and extract the doctrine of each
successively. But this suggestion has to be given up as soon as it is
mentioned. For although the philosophy of Plato is in itself a
systematic and coherent body of thought, he did not express it in a
systematic way. On the contrary, he scatters his ideas in all
directions. He throws them out at random in any order. What logically
comes first often appears last. It may be found at the end of a
dialogue, and the next step in reasoning may make its appearance at
the beginning, or even in a totally different dialogue. If, therefore,
we are to get any connected view of the system, we must abandon
Plato's own order of exposition, and piece the thought together for
ourselves. We must begin {177} with what logically comes first,
wherever we may find it, and proceed with the exposition in the same
manner.
A similar difficulty attends the question of the division of Plato's
philosophy. He himself has given us no single and certain principle of
division. But the principle usually adopted divides his philosophy
into Dialectic, Physics, and Ethics. Dialectic, or the theory of
Ideas, is Plato's doctrine of the nature of the absolute reality.
Physics is the theory of phenomenal existence in space and time, and
includes therefore the doctrine of the soul and its migrations, since
these are happenings in time. Ethics includes politics, the theory of
the duty of man as a citizen, as well as the ethics of the individual.
Certain portions of the system, the doctrine of Eros, for example, do
not fall very naturally into any of these divisions. But, on the other
hand, though some dialogues are mixed as to their subject matter,
others, and those the most important, fall almost exclusively into one
or other division. For example, the "Timaeus," the "Phaedo," and the
"Phaedrus," are physical. The "Philebus," the "Gorgias," and the
"Republic," are ethical. The "Theaetetus," the "Sophist," and the
"Parmenides," are dialectical.
2. The Theory of Knowledge.
The theory of Ideas is itself based upon the theory of knowledge. What
is knowledge? What is truth? Plato opens the discussion by telling us
first what knowledge and truth are not. His object here is the
refutation of false theories. These must be disposed of to clear the
ground preparatory to positive exposition. The first such false theory
which he attacks is that knowledge {178} is perception. To refute this
is the main object of the "Theaetetus." His arguments may be
summarized as follows:--
(1) That knowledge is perception is the theory of Protagoras and the
Sophists, and we have seen to what results it leads. What it amounts
to is that what appears to each individual true is true for that
individual. But this is at any rate false in its application to our
judgment of future events. The frequent mistakes which men make about
the future show this. It may appear to me that I shall be Chief
Justice next year. But instead of that, I find myself, perhaps, in
prison. In general, what appears to each individual to be the truth
about the future frequently does not turn out so in the event.
(2) Perception yields contradictory impressions. The same object
appears large when near, small when removed to a distance. Compared
with some things it is light, with others heavy. In one light it is
white, in another green, and in the dark it has no colour at all.
Looked at from one angle this piece of paper seems square, from
another it appears to be a rhombus. Which of all these impressions is
true? To know which is true, we must be able to exercise a choice
among these varying impressions, to prefer one to another, to
discriminate, to accept this and reject that. But if knowledge is
perception, then we have no right to give one perception preference
over another. For all perceptions are knowledge. All are true.
(3) This doctrine renders all teaching, all discussion, proof, or
disproof, impossible. Since all perceptions are equally true, the
child's perceptions must be just as much the truth as those of his
teachers. His teachers, {179} therefore, can teach him nothing. As to
discussion and proof, the very fact that two people dispute about
anything implies that they believe in the existence of an objective
truth. Their impressions, if they contradict each other, cannot both
be true. For if so, there is nothing to dispute about. Thus all proof
and refutation are rendered futile by the theory of Protagoras.
(4) If perception is truth, man is the measure of all things, in his
character as a percipient being. But since animals are also percipient
beings, the lowest brute must be, equally with man, the measure of all
things.
(5) The theory of Protagoras contradicts itself. For Protagoras admits
that what appears to me true is true. If, therefore, it appears to me
true that the doctrine of Protagoras is false, Protagoras himself must
admit that it is false.
(6) It destroys the objectivity of truth, and renders the distinction
between truth and falsehood wholly meaningless. The same thing is true
and false at the same time, true for you and false for me. Hence it
makes no difference at all whether we say that a proposition is true,
or whether we say that it is false. Both statements mean the same
thing, that is to say, neither of them means anything. To say that
whatever I perceive is true for me merely gives a new name to my
perception, but does not add any value to it.
(7) In all perception there are elements which are not contributed by
the senses. Suppose I say, "This piece of paper is white." This, we
might think, is a pure judgment of perception. Nothing is stated
except what I perceive by means of my senses. But on consideration it
turns out that this is not correct. First of all I must {180} think
"this piece of paper." Why do I call it paper? My doing so means that
I have classified it. I have mentally compared it with other pieces of
paper, and decided that it is of a class with them. My thought, then,
involves comparison and classification. The object is a compound
sensation of whiteness, squareness, etc. I can only recognise it as a
piece of paper by identifying these sensations, which I have now, with
sensations received from other similar objects in the past. And not
only must I recognize the sameness of the sensations, but I must
recognize their difference from other sensations. I must not confound
the sensations I receive from paper with those which I receive from a
piece of wood. Both identities and differences of sensations must be
known before I can say "this piece of paper." The same is true when I
go on to say that it "is white." This is only possible by classifying
it with other white objects, and differentiating it from objects of
other colours. But the senses themselves cannot perform these acts of
comparison and contrast. Each sensation is, so to speak, an isolated
dot. It cannot go beyond itself to compare itself with others. This
operation must be performed by my mind, which acts as a co-ordinating
central authority, receiving the isolated sensations, combining,
comparing, and contrasting them. This is particularly noticeable in
cases where we compare sensations of one sense with those of another.
Feeling a ball with my fingers, I say it feels round. Looking at it
with my eyes, I say it looks round. But the feel is quite a different
sensation from the look. Yet I use the same word, "round," to describe
both. And this shows that I have identified the two sensations. This
{181} cannot be done by the senses themselves. For my eyes cannot
feel, and my fingers cannot see. It must be the mind itself, standing
above the senses, which performs the identification. Thus the ideas of
identity and difference are not yielded to me by my senses. The
intellect itself introduces them into things. Yet they are involved in
all knowledge, for they are involved even in the simplest acts of
knowledge, such as the proposition, "This is white." Knowledge,
therefore, cannot consist simply of sense-impressions, as Protagoras
thought, for even the simplest propositions contain more than
sensation.
If knowledge is not the same as perception, neither is it, on the
other hand, the same as opinion. That knowledge is opinion is the
second false theory that Plato seeks to refute. Wrong opinion is
clearly not knowledge. But even right opinion cannot be called
knowledge. If I say, without any grounds for the statement, that there
will be a thunderstorm next Easter Sunday, it may chance that my
statement turns out to be correct. But it cannot be said that, in
making this blind guess, I had any knowledge, although, as it turned
out, I had right opinion. Right opinion may also be grounded, not on
mere guess-work, but on something which, though better, is still not
true understanding. We often feel intuitively, or instinctively, that
something is true, though we cannot give any definite grounds for our
belief. The belief may be quite correct, but it is not, according to
Plato, knowledge. It is only right opinion. To possess knowledge, one
must not only know that a thing is so, but why it is so. One must know
the reasons. Knowledge must be full and complete understanding,
rational comprehension, and not mere instinctive belief. {182} It must
be grounded on reason, and not on faith. Right opinion may be produced
by persuasion and sophistry, by the arts of the orator and
rhetorician. Knowledge can only be produced by reason. Right opinion
may equally be removed by the false arts of rhetoric, and is therefore
unstable and uncertain. But true knowledge cannot be thus shaken. He
who truly knows and understands cannot be robbed of his knowledge by
the glamour of words. Opinion, lastly, may be true or false. Knowledge
can only be true.
These false theories being refuted, we can now pass to the positive
side of the theory of knowledge. If knowledge is neither perception
nor opinion, what is it? Plato adopts, without alteration, the
Socratic doctrine that all knowledge is knowledge through concepts.
This, as I explained in the lecture on Socrates, gets rid of the
objectionable results of the Sophistic identification of knowledge
with perception. A concept, being the same thing as a definition, is
something fixed and permanent, not liable to mutation according to the
subjective impressions of the individual. It gives us objective truth.
This also agrees with Plato's view of opinion. Knowledge is not
opinion, founded on instinct or intuition. Knowledge is founded on
reason. This is the same as saying that it is founded upon concepts,
since reason is the faculty of concepts.
But if Plato, in answering the question, "What is knowledge?" follows
implicitly the teaching of Socrates, he yet builds upon this teaching
a new and wholly un-Socratic metaphysic of his own. The Socratic
theory of knowledge he now converts into a theory of the nature of
reality. This is the subject-matter of Dialectic.
{183}
3. Dialectic, or the Theory of Ideas.
The concept had been for Socrates merely a rule of thought.
Definitions, like guide-rails, keep thought upon the straight path; we
compare any act with the definition of virtue in order to ascertain
whether it is virtuous. But what was for Socrates merely regulative of
thought, Plato now transforms into a metaphysical substance. His
theory of Ideas is the theory of the objectivity of concepts. That the
concept is not merely an idea in the mind, but something which has a
reality of its own, outside and independent of the mind--this is the
essence of the philosophy of Plato.
How did Plato arrive at this doctrine? It is founded upon the view
that truth means the correspondence of one's ideas with the facts of
existence. If I see a lake of water, and if there really is such a
lake, then my idea is true. But if there is no lake, then my idea is
false. It is an hallucination. Truth, according to this view, means
that the thought in my mind is a copy of something outside my mind.
Falsehood consists in having an idea which is not a copy of anything
which really exists. Knowledge, of course, means knowledge of the
truth. And when I say that a thought in my mind is knowledge, I must
therefore mean that this thought is a copy of something that exists.
But we have already seen that knowledge is the knowledge of concepts.
And if a concept is true knowledge, it can only be true in virtue of
the fact that it corresponds to an objective reality. There must,
therefore, be general ideas or concepts, outside my mind. It were a
contradiction to suppose, on the one hand, that the concept is true
knowledge, and on the other, that it corresponds to nothing external
{184} to us. This would be like saying that my idea of the lake of
water is a true idea, but that no such lake really exists. The concept
in my mind must be a copy of the concept outside it.
Now if knowledge by concepts is true, our experiences through
sensation must be false. Our senses make us aware of many individual
horses. Our intellect gives us the concept of the horse in general. If
the latter is the sole truth, the former must be false. And this can
only mean that the objects of sensation have no true reality. What has
reality is the concept; what has no reality is the individual thing
which is perceived by the senses. This and that particular horse have
no true being. Reality belongs only to the idea of the horse in
general.
Let us approach this theory from a somewhat different direction.
Suppose I ask you the question, "What is beauty?" You point to a rose,
and say, "Here is beauty." And you say the same of a woman's face, a
piece of woodland scenery, and a clear moonlight night. But I answer
that this is not what I want to know. I did not ask what things are
beautiful, but what is beauty. I did not ask for many things, but for
one thing, namely, beauty. If beauty is a rose, it cannot be
moonlight, because a rose and moonlight are quite different things. By
beauty we mean, not many things, but one. This is proved by the fact
that we use only one word for it. And what I want to know is what this
one beauty is, which is distinct from all beautiful objects. Perhaps
you will say that there is no such thing as beauty apart from
beautiful objects, and that, though we use one word, yet this is only
a manner of {185} speech, and that there are in reality many beauties,
each residing in a beautiful object. In that case, I observe that,
though the many beauties are all different, yet, since you use the one
word to describe them all, you evidently think that they are similar
to each other. How do you know that they are similar? Your eyes cannot
inform you of this similarity, because it involves comparison, and we
have already seen that comparison is an act of the mind, and not of
the senses. You must therefore have an idea of beauty in your mind,
with which you compare the various beautiful objects and so recognise
them as all resembling your idea of beauty, and therefore as
resembling each other. So that there is at any rate an idea of one
beauty in your mind. Either this idea corresponds to something outside
you, or it does not. In the latter case, your idea of beauty is a mere
invention, a figment of your own brain. If so, then, in judging
external objects by your subjective idea, and in making it the
standard of whether they are beautiful or not, you are back again at
the position of the Sophists. You are making yourself and the fancies
of your individual brain the standard of external truth. Therefore,
the only alternative is to believe that there is not only an idea of
beauty in your mind, but that there is such a thing as the one beauty
itself, of which your idea is a copy. This beauty exists outside the
mind, and it is something distinct from all beautiful objects.
What has been said of beauty may equally be said of justice, or of
goodness, or of whiteness, or of heaviness. There are many just acts,
but only one justice, since we use one word for it. This justice must
be a real thing, distinct from all particular just acts. Our ideas of
justice {186} are copies of it. So also there are many white objects,
but also the one whiteness.
Of the above examples, several are very exalted moral ideas, such as
beauty, justice, and goodness. But the case of whiteness will serve to
show that the theory attributes reality not only to exalted ideas, but
to others also. In fact, we might quite well substitute evil for
goodness, and all the same arguments would apply. Or we might take a
corporeal object such as the horse, and ask what "horse" means. It
does not mean the many individual horses, for since one word is used
it must mean one thing, which is related to individual horses, just as
whiteness is related to individual white things. It means the
universal horse, the idea of the horse in general, and this, just as
much as goodness or beauty, must be something objectively real.
Now beauty, justice, goodness, whiteness, the horse in general, are
all concepts. The idea of beauty is formed by including what is common
to all beautiful objects, and excluding those points in which they
differ. And this, as we have seen, is just what is meant by a concept.
Plato's theory, therefore, is that concepts are objective realities.
And he gives to these objective concepts the technical name Ideas.
This is his answer to the chief question of philosophy, namely, what,
amid all the appearances and unrealities of things, is that absolute
and ultimate reality, from which all else is to be explained? It
consists, for Plato, in Ideas.
Let us see next what the characteristics of the Ideas are. In the
first place, they are substances. Substance is a technical term in
philosophy, but its philosophical meaning is merely a more consistent
development of its {187} popular meaning. In common talk, we generally
apply the word substance to material things such as iron, brass, wood,
or water. And we say that these substances possess qualities. For
example, hardness and shininess are qualities of the substance iron.
The qualities cannot exist apart from the substances. They do not
exist on their own account, but are dependent on the substance. The
shininess cannot exist by itself. There must be a shiny something.
But, according to popular ideas, though the qualities are not
independent of the substance, the substance is independent of the
qualities. The qualities derive their reality from the substance. But
the substance has reality in itself. The philosophical use of the term
substance is simply a more consistent application of this idea.
Substance means, for the philosopher, that which has its whole being
in itself, whose reality does not flow into it from anything else, but
which is the source of its own reality. It is self-caused, and
self-determined. It is the ground of other things, but itself has no
ground except itself. For example, if we believe the popular Christian
idea that God created the world, but is Himself an ultimate and
uncreated being, then, since the world depends for its existence upon
God, but God's existence depends only upon Himself, God is a substance
and the world is not. In this sense the word is correctly used in the
Creed where it speaks of God as "three persons, but one substance."
Again, if, with the Idealists, we think that mind is a self-existent
reality, and that matter owes its existence to mind, then in that case
matter is not substance, but mind is. In this technical sense the
Ideas are substances. They are absolute and ultimate realities. {188}
Their whole being is in themselves. They depend on nothing, but all
things depend on them. They are the first principles of the universe.
Secondly, the Ideas are universal. An Idea is not any particular
thing. The Idea of the horse is not this or that horse. It is the
general concept of all horses. It is the universal horse. For this
reason the Ideas are, in modern times, often called "universals."
Thirdly, the Ideas are not things, but thoughts. There is no such
thing as the horse-in-general. If there were, we should be able to
find it somewhere, and it would then be a particular thing instead of
a universal. But in saying that the Ideas are thoughts, there are two
mistakes to be carefully avoided. The first is to suppose that they
are the thoughts of a person, that they are your thoughts or my
thoughts. The second is to suppose that they are thoughts in the mind
of God. Both these views are wrong. It would be absurd to suppose that
our thoughts can be the cause of the universe. Our concepts are indeed
copies of the Ideas, but to confuse them with the Ideas themselves is,
for Plato, as absurd as to confuse our idea of a mountain with the
mountain itself. Nor are they the thoughts of God. They are indeed
sometimes spoken of as the "Ideas in the divine mind." But this is
only a figurative expression. We can, if we like, talk of the sum of
all the Ideas as constituting the "divine mind." But this means
nothing in particular, and is only a poetical phrase. Both these
mistakes are due to the fact that we find it difficult to conceive of
thoughts without a thinker. This, however, is just what Plato meant.
They are not subjective ideas, that is, the ideas in a particular and
existent {189} mind. They are objective Ideas, thoughts which have
reality on their own account, independently of any mind.
Fourthly, each Idea is a unity. It is the one amid the many. The Idea
of man is one, although individual men are many. There cannot be more
than one Idea for each class of objects. If there were several Ideas
of justice, we should have to seek for the common element among them,
and this common element would itself constitute the one Idea of
justice.
Fifthly, the Ideas are immutable and imperishable. A concept is the
same as a definition. And the whole point in a definition is that it
should always be the same. The object of a definition is to compare
individual things with it, and to see whether they agree with it or
not. But if the definition of a triangle differed from day to day, it
would be useless, since we could never say whether any particular
figure were a triangle or not, just as the standard yard in the Tower
of London would be useless if it changed in length, and were twice as
long to-day as it was yesterday. A definition is thus something
absolutely permanent, and a definition is only the expression in words
of the nature of an Idea. Consequently the Ideas cannot change. The
many beautiful objects arise and pass away, but the one Beauty neither
begins nor ends. It is eternal, unchangeable, and imperishable. The
many beautiful things are but the fleeting expressions of the one
eternal beauty. The definition of man would remain the same, even if
all men were destroyed. The Idea of man is eternal, and remains
untouched by the birth, old age, decay, and death, of individual men.
Sixthly, the Ideas are the Essences of all things. The definition
gives us what is essential to a thing. If we {190} define man as a
rational animal, this means that reason is of the essence of man. The
fact that this man has a turned-up nose, and that man red hair, are
accidental facts, not essential to their humanity. We do not include
them in the definition of man.
Seventhly, each Idea is, in its own kind, an absolute perfection, and
its perfection is the same as its reality. The perfect man is the one
universal type-man, that is, the Idea of man, and all individual men
deviate more or less from this perfect type. In so far as they fall
short of it, they are imperfect and unreal.
Eighthly, the Ideas are outside space and time. That they are outside
space is obvious. If they were in space, they would have to be in some
particular place. We ought to be able to find them somewhere. A
telescope or microscope might reveal them. And this would mean that
they are individual and particular things, and not universals at all.
They are also outside time. For they are unchangeable and eternal; and
this does not mean that they are the same at all times. If that were
so, their immutability would be a matter of experience, and not of
reason. We should, so to speak, have to look at them from time to time
to see that they had not really changed. But their immutability is not
a matter of experience, but is known to thought. It is not merely that
they are always the same in time, but that time is irrelevant to them.
They are timeless. In the "Timaeus" eternity is distinguished from
infinite time. The latter is described as a mere copy of eternity.
Ninthly, the Ideas are rational, that is to say, they are apprehended
through reason. The finding of the common element in the manifold is
the work of inductive {191} reason, and through this alone is
knowledge of the Ideas possible. This should be noted by those persons
who imagine that Plato was some sort of benevolent mystic. The
imperishable One, the absolute reality, is apprehended, not by
intuition, or in any kind of mystic ecstasy, but only by rational
cognition and laborious thought.
Lastly, towards the end of his life, Plato identified the Ideas with
the Pythagorean numbers. We know this from Aristotle, but it is not
mentioned in the dialogues of Plato himself. It appears to have been a
theory adopted in old age, and set forth in the lectures which
Aristotle attended. It is a retrograde step, and tends to degrade the
great and lucid idealism of Plato into a mathematical mysticism. In
this, as in other respects, the influence of the Pythagoreans upon
Plato was harmful.
It results from this whole theory of Ideas that there are two sources
of human experience, sense-perception and reason. Sense-perception has
for its object the world of sense; reason has for its object the
Ideas. The world of sense has all the opposite characteristics to the
Ideas. The Ideas are absolute reality, absolute Being. Objects of
sense are absolute unreality, not-being, except in so far as the Ideas
are in them. Whatever reality they have they owe to the Ideas. There
is in Plato's system a principle of absolute not-being which we shall
consider when we come to deal with his Physics. Objects of sense
participate both in the Ideas and in this not-being. They are,
therefore, half way between Being and not-being. They are half real.
Ideas, again, are universal; things of sense are always particular and
individual. The Idea is one, the sense-object is always {192} a
multiplicity. Ideas are outside space and time, things of sense are
both temporal and spatial. The Idea is eternal and immutable;
sense-objects are changeable and in perpetual flux.
As regards the last point, Plato adopts the view of Heracleitus that
there is an absolute Becoming, and he identifies it with the world of
sense, which contains nothing stable and permanent, but is a constant
flow. The Idea always is, and never becomes; the thing of sense always
becomes, and never is. It is for this reason that, in the opinion of
Plato, no knowledge of the world of sense is possible, for one can
have no knowledge of that which changes from moment to moment.
Knowledge is only possible if its subject stands fixed before the
mind, is permanent and changeless. The only knowledge, then, is
knowledge of the Ideas.
This may seem, at first sight, a very singular doctrine. That there
can be no knowledge of sense-objects would, it might seem to us
moderns, involve the denial that modern physical science, with all its
exactitude and accumulated knowledge, is knowledge at all. And surely,
though all earthly things arise and pass away, many of them last long
enough to admit of knowledge. Surely the mountains are sufficiently
permanent to allow us to know something of them. They have relative,
though not absolute, permanence. This criticism is partly justified.
Plato did underestimate the value of physical knowledge. But for the
most part, the criticism is a misunderstanding. By the world of sense
Plato means bare sensation with no rational element in it. Now
physical science has not such crude sensation for its object. Its
objects are rationalized sensations. {193} If, in Plato's manner, we
think only of pure sensation, then it is true that it is nothing but a
constant flux without stability; and knowledge of it is impossible.
The mountains are comparatively permanent. But our sensation of the
mountains is perpetually changing. Every change of light, every cloud
that passes over the sun, changes the colours and the shades. Every
time we move from one situation to another, the mountain appears a
different shape. The permanence of the mountain itself is due to the
fact that all these varying sensations are identified as sensations of
one and the same object. The idea of identity is involved here, and it
is, as it were, a thread upon which these fleeting sensations are
strung. But the idea of identity cannot be obtained from the senses.
It is introduced into things by reason. Hence knowledge of this
permanent mountain is only possible through the exercise of reason. In
Plato's language, all we can know of the mountain is the Ideas in
which it participates. To revert to a previous example, even the
knowledge "this paper is white" involves the activity of intellect,
and is impossible through sensation alone. Bare sensation is a flow,
of which no knowledge is possible.
Aristotle observes that Plato's theory of Ideas has three sources, the
teachings of the Eleatics, of Heracleitus, and of Socrates. From
Heracleitus, Plato took the notion of a sphere of Becoming, and it
appears in his system as the world of sense. From the Eleatics he took
the idea of a sphere of absolute Being. From Socrates he took the
doctrine of concepts, and proceeded to identify the Eleatic Being with
the Socratic concepts. This gives him his theory of Ideas.
{194}
Sense objects, so far as they are knowable, that is so far as they are
more than bare sensations, are so only because the Idea resides in
them. And this yields the clue to Plato's teaching regarding the
relation of sense objects to the Ideas. The Ideas are, in the first
place the cause, that is to say, the ground (not the mechanical cause)
of sense-objects. The Ideas are the absolute reality by which
individual things must be explained. The being of things flows into
them from the Ideas. They are "copies," "imitations," of the Ideas. In
so far as they resemble the Idea, they are real; in so far as they
differ from it, they are unreal. In general, sense objects are, in
Plato's opinion, only very dim, poor and imperfect copies of the
Ideas. They are mere shadows, and half-realities. Another expression
frequently used by Plato to express this relationship is that of
"participation." Things participate in the Ideas. White objects
participate in the one whiteness, beautiful objects, in the one
beauty. In this way beauty itself is the cause or explanation of
beautiful objects, and so of all other Ideas. The Ideas are thus both
transcendent and immanent; immanent in so far as they reside in the
things of sense, transcendent inasmuch as they have a reality of their
own apart from the objects of sense which participate in them. The
Idea of man would still be real even if all men were destroyed, and it
was real before any man existed, if there ever was such a time. For
the Ideas, being timeless, cannot be real now and not then.
Of what kinds of things are there Ideas? That there are moral Ideas,
such as Justice, Goodness, and Beauty, Ideas of corporeal things, such
as horse, man, tree, star, river, and Ideas of qualities, such as
whiteness, heaviness, {195} sweetness, we have already seen. But there
are Ideas not only of natural corporeal objects, but likewise of
manufactured articles; there are Ideas of beds, tables, clothes. And
there are Ideas not only of exalted moral entities, such as Beauty and
Justice. There are also the Ideal Ugliness, and the Ideal Injustice.
There are even Ideas of the positively nauseating, such as hair,
filth, and dirt. This is asserted in the "Parmenides." In that
dialogue Plato's teaching is put into the mouth of Parmenides. He
questions the young Socrates whether there are Ideas of hair, filth,
and dirt. Socrates denies that there can be Ideas of such base things.
But Parmenides corrects him, and tells him that, when he has attained
the highest philosophy, he will no longer despise such things.
Moreover, these Ideas of base things are just as much perfection in
their kind as Beauty and Goodness are in theirs. In general, the
principle is that there must be an Idea wherever a concept can be
formed; that is, wherever there is a class of many things called by
one name.
We saw, in treating of the Eleatics, that for them the absolute Being
contained no not-being, and the absolute One no multiplicity. And it
was just because they denied all not-being and multiplicity of the
absolute reality that they were unable to explain the world of
existence, and were forced to deny it altogether. The same problem
arises for Plato. Is Being absolutely excludent of not-being? Is the
Absolute an abstract One, utterly exclusive of the many? Is his
philosophy a pure monism? Is it a pluralism? Or is it a combination of
the two? These questions are discussed in the "Sophist" and the
"Parmenides."
{196}
Plato investigates the relations of the One and the many, Being and
not-being, quite in the abstract. He decides the principles involved,
and leaves it to the reader to apply them to the theory of Ideas.
Whether the Absolute is one or many, Being or not-being, can be
decided independently of any particular theory of the nature of the
Absolute, and therefore independently of Plato's own theory, which was
that the Absolute consists of Ideas. Plato does not accept the Eleatic
abstraction. The One cannot be simply one, for every unity must
necessarily be a multiplicity. The many and the One are correlative
ideas which involve each other. Neither is thinkable without the
other. A One which is not many is as absurd an abstraction as a whole
which has no parts. For the One can only be defined as that which is
not many, and the many can only be defined as the not-one. The One is
unthinkable except as standing out against a background of the many.
The idea of the One therefore involves the idea of the many, and
cannot be thought without it. Moreover, an abstract One is unthinkable
and unknowable, because all thought and knowledge consist in applying
predicates to subjects, and all predication involves the duality of
its subject.
Consider the simplest affirmation that can be made about the One,
namely, "The One is." Here we have two things, "the One," and "is,"
that is to say, being. The proposition means that the One is Being.
Hence the One is two. Firstly, it is itself, "One." Secondly, it is
"Being," and the proposition affirms that these two things are one.
Similarly with any other predicate we apply to the One. Whatever we
say of it involves its duality. Thus we find that all systems of
thought which {197} postulate an abstract unity as ultimate reality,
such as Eleaticism, Hinduism, and the system of Spinoza, attempt to
avoid the difficulty by saying nothing positive about the One. They
apply to it only negative predicates, which tell us not what it is,
but what it is not. Thus the Hindus speak of Brahman as form_less_,
_im_mutable, _im_perishable, _un_moved, _un_created. But this, of course,
is a futile expedient. In the first place, even a negative predicate
involves the duality of the subject. And, in the second place, a
negative predicate is always, by implication, a positive one. You
cannot have a negative without a positive. To deny one thing is to
affirm its opposite. To deny motion of the One, by calling it the
unmoved, is to affirm rest of it. Thus a One which is not also a many
is unthinkable. Similarly, the idea of the many is inconceivable
without the idea of the One. For the many is many ones. Hence the One
and the many cannot be separated in the Eleatic manner. Every unity
must be a unity of the many. And every many is _ipso facto_ a unity,
since we think the many in one idea, and, if we did not, we should not
even know that it is a many. The Absolute must therefore be neither an
abstract One, nor an abstract many. It must be a many in one.
Similarly, Being cannot totally exclude not-being. They are, just as
much as the One and the many, correlatives, which mutually involve
each other. The being of anything is the not-being of its opposite.
The being of light is the not-being of darkness. All being, therefore,
has not-being in it.
Let us apply these principles to the theory of Ideas. The absolute
reality, the world of Ideas, is many, since {198} there are many
Ideas, but it is one, because the Ideas are not isolated units, but
members of a single organized system. There is, in fact, a hierarchy
of Ideas. Just as the one Idea presides over many individual things of
which it is the common element, so one higher Idea presides over many
lower Ideas, and is the common element in them. And over this higher
Idea, together with many others, a still higher Idea will rule. For
example, the Ideas of whiteness, redness, blueness, are all subsumed
under the one Idea of colour. The Ideas of sweetness and bitterness
come under the one Idea of taste. But the Ideas of colour and taste
themselves stand under the still higher Idea of quality. In this way,
the Ideas form, as it were, a pyramid, and to this pyramid there must
be an apex. There must be one highest Idea, which is supreme over all
the others. This Idea will be the one final and absolutely real Being
which is the ultimate ground, of itself, of the other Ideas, and of
the entire universe. This Idea is, Plato tells us, the Idea of the
Good. We have seen that the world of Ideas is many, and we now see
that it is one. For it is one single system culminating in one supreme
Idea, which is the highest expression of its unity. Moreover, each
separate Idea is, in the same way, a many in one. It is one in regard
to itself. That is to say, if we ignore its relations to other Ideas,
it is, in itself, single. But as it has also many relations to other
Ideas, it is, in this way, a multiplicity.
Every Idea is likewise a Being which contains not-being. For each Idea
combines with some Ideas and not with others. Thus the Idea of
corporeal body combines both with the Idea of rest and that of motion.
{199} But the Ideas of rest and motion will not combine with each
other. The Idea of rest, therefore, is Being in regard to itself,
not-being in regard to the Idea of motion, for the being of rest is
the not-being of motion. All Ideas are Being in regard to themselves,
and not-being in regard to all those other Ideas with which they do
not combine.
In this way there arises a science of Ideas which is called dialectic.
This word is sometimes used as identical with the phrase, "theory of
Ideas." But it is also used, in a narrower sense, to mean the science
which has to do with the knowledge of which Ideas will combine and
which not. Dialectic is the correct joining and disjoining of Ideas.
It is the knowledge of the relations of all the Ideas to each other.
The attainment of this knowledge is, in Plato's opinion, the chief
problem of philosophy. To know all the Ideas, each in itself and in
its relations to other Ideas, is the supreme task. This involves two
steps. The first is the formation of concepts. Its object is to know
each Idea separately, and its procedure is by inductive reason to find
the common element in which the many individual objects participate.
The second step consists in the knowledge of the inter-relation of
Ideas, and involves the two processes of classification and division.
Classification and division both have for their object to arrange the
lower Ideas under the proper higher Ideas, but they do this in
opposite ways. One may begin with the lower Ideas, such as redness,
whiteness, etc., and range them under their higher Idea, that of
colour. This is classification. Or one may begin with the higher Idea,
colour, and divide it into the lower Ideas, red, white, {200} etc.
Classification proceeds from below upwards. Division proceeds from
above downwards. Most of the examples of division which Plato gives
are divisions by dichotomy. We may either divide colour straight away
into red, blue, white, etc.; or we may divide each class into two
sub-classes. Thus colour will be divided into red and not-red, not-red
into white and not-white, not-white into blue and not-blue, and so on.
This latter process is division by dichotomy, and Plato prefers it
because, though it is tedious, it is very exhaustive and systematic.
Plato's actual performance of the supreme task of dialectic, the
classification and arrangement of all Ideas, is not great. He has made
no attempt to complete it. All he has done is to give us numerous
examples. And this is, in reality, all that can be expected, for the
number of Ideas is obviously infinite, and therefore the task of
arranging them cannot be completed. There is, however, one important
defect in the dialectic, which Plato ought certainly to have remedied.
The supreme Idea, he tells us, is the Good. This, as being the
ultimate reality, is the ground of all other Ideas. Plato ought
therefore to have derived all other Ideas from it, but this he has not
done. He merely asserts, in a more or less dogmatic way, that the Idea
of the Good is the highest, but does nothing to connect it with the
other Ideas. It is easy to see, however, why he made this assertion.
It is, in fact, a necessary logical outcome of his system. For every
Idea is perfection in its kind. All the Ideas have perfection in
common. And just as the one beauty is the Idea which presides over all
beautiful things, so the one perfection must be the supreme Idea which
presides {201} over all the perfect Ideas. The supreme Idea,
therefore, must be perfection itself, that is to say, the Idea of the
Good. On the other hand it might, with equal force, be argued that
since all the Ideas are substances, therefore the highest Idea is the
Idea of substance. All that can be said is that Plato has left these
matters in obscurity, and has merely asserted that the highest Idea is
the Good.
Consideration of the Idea of the Good leads us naturally to enquire
how far Plato's system is teleological in character. A little
consideration will show that it is out and out teleological. We can
see this both by studying the many lower Ideas, and the one supreme
Idea. Each Idea is perfection of its kind. And each Idea is the ground
of the existence of the individual objects which come under it. Thus
the explanation of white objects is the perfect whiteness, of
beautiful objects the perfect beauty. Or we may take as our example
the Idea of the State which Plato describes in the "Republic." The
ordinary view is that Plato was describing a State which was the
invention of his own fancy, and is therefore to be regarded as
entirely unreal. This is completely to misunderstand Plato. So far was
he from thinking the ideal State unreal, that he regarded it, on the
contrary, as the only real State. All existent States, such as the
Athenian or the Spartan, are unreal in so far as they differ from the
ideal State. And moreover, this one reality, the ideal State, is the
ground of the existence of all actual States. They owe their existence
to its reality. Their existence can only be explained by it. Now since
the ideal State is not yet reached in fact, but is the perfect State
towards which all actual States tend, it is clear that we have here
{202} a teleological principle. The real explanation of the State is
not to be found in its beginnings in history, in an original contract,
or in biological necessities, but in its end, the final or perfect
State. Or, if we prefer to put it so; the true beginning is the end.
The end must be in the beginning, potentially and ideally, otherwise
it could never begin: It is the same with all other things. Man is
explained by the ideal man, the perfect man; white things by the
perfect whiteness, and so on. Everything is explained by its end, and
not by its beginning. Things are not explained by mechanical causes,
but by reasons.
And the teleology of Plato culminates in the Idea of the Good. That
Idea is the final explanation of all other Ideas, and of the entire
universe. And to place the final ground of all things in perfection
itself means that the universe arises out of that perfect end towards
which all things move.
Another matter which requires elucidation here is the place which the
conception of God holds in Plato's system. He frequently uses the word
God both in the singular and the plural, and seems to slip with
remarkable ease from the monotheistic to the polytheistic manner of
speaking. In addition to the many gods, we have frequent reference to
the one supreme Creator, controller, and ruler of the world, who is
further conceived as a Being providentially watching over the lives of
men. But in what relation does this supreme God stand to the Ideas,
and especially to the Idea of the Good? If God is separate from the
highest Idea, then, as Zeller points out, [Footnote 13] only three
relations are possible, all of which are {203} equally objectionable.
Firstly, God may be the cause or ground of the Idea of the Good. But
this destroys the substantiality of the Idea, and indeed, destroys
Plato's whole system. The very essence of his philosophy is that the
Idea is the ultimate reality, which is self-existent, and owes its
being to nothing else. But this theory makes it a mere creature of
God, dependent on Him for its existence. Secondly, God may owe His
being to the Idea. The Idea may be the ground of God's existence as it
is the ground of all else in the universe. But this theory does
violence to the idea of God, turning Him into a mere derivative
existence, and, in fact, into an appearance. Thirdly, God and the Idea
may be co-ordinate in the system as equally primordial independent
ultimate realities. But this means that Plato has given two mutually
inconsistent accounts of the ultimate reality, or, if not, that his
system is a hopeless dualism. As none of these theories can be
maintained, it must be supposed that God is identical with the Idea of
the Good, and we find certain expressions in the "Philebus" which seem
clearly to assert this. But in that case God is not a personal God at
all, since the Idea is not a person. The word God, if used in this
way, is merely a figurative term for the Idea. And this is the most
probable theory, if we reflect that there is in fact no room for a
personal God in a system which places all reality in the Idea, and
that to introduce such a conception threatens to break up the whole
system. Plato probably found it useful to take the popular conceptions
about the personality of God or the gods and use them, in mythical
fashion, to express his Ideas. Those parts of Plato which speak of
God, and the governance of God, {204} are to be interpreted on the
same principles as the other Platonic myths.
[Footnote 13: _Plato and the Older Academy_, chap. vi.]
Before closing our discussion of dialectic, it may be well to consider
what place it occupies in the life of man, and what importance is
attached to it. Here Plato's answer is emphatic. Dialectic is the
crown of knowledge, and knowledge is the crown of life. All other
spiritual activities have value only in so far as they lead up to the
knowledge of the Idea. All other subjects of intellectual study are
merely preparatory to the study of philosophy. The special sciences
have no value in themselves, but they have value inasmuch as their
definitions and classifications form a preparation for the knowledge
of Ideas. Mathematics is important because it is a stepping-stone from
the world of sense to the Ideas. Its objects, namely, numbers and
geometrical figures, resemble the Ideas in so far as they are
immutable, and they resemble sense-objects in so far as they are in
space or time. In the educational curriculum of Plato, philosophy
comes last. Not everyone may study it. And none may study it till he
has been through all the preparatory stages of education, which form a
rigorous discipline of the mind before it finally enters upon
dialectic. Thus all knowledge ends in dialectic, and that life has not
attained its end which falls short of philosophy.
Perhaps the most striking illustration of the subordination of all
spiritual activities to philosophy is to be found in the doctrine of
Eros, or Love. The phrase "platonic love" is on the lips of many, but,
as a rule, something very different from Plato's own doctrine is
meant. According to him, love is always concerned with beauty, and his
teaching on the subject is expounded {205} chiefly in the "Symposium,"
He believed that before birth the soul dwelt disembodied in the pure
contemplation of the world of Ideas. Sinking down into a body,
becoming immersed in the world of sense, it forgets the Ideas. The
sight of a beautiful object reminds it of that one Idea of beauty of
which the object is a copy. This accounts for the mystic rapture, the
emotion, the joy, with which we greet the sight of the beautiful.
Since Plato had expressly declared that there are Ideas of the ugly as
well as of the beautiful, that there are Ideas, for example, of hair,
filth, and dirt, and since these Ideas are just as divine and perfect
as the Idea of the beautiful, we ought, on this theory, to greet the
ugly, the filthy, and the nauseating, with a ravishment of joy similar
to that which we experience in the presence of beauty. Why this is not
the case Plato omitted to explain. However, having learned to love the
one beautiful object, the soul passes on to the love of others. Then
it perceives that it is the same beauty which reveals itself in all
these. It passes from the love of beautiful forms to the love of
beautiful souls, and from that to the love of beautiful sciences. It
ceases to be attached to the many objects, as such, that is to say, to
the sensuous envelopes of the Idea of beauty. Love passes into the
knowledge of the Idea of beauty itself, and from this to the knowledge
of the world of Ideas in general. It passes in fact into philosophy.