Theaetetus
as in the Gorgias or Sophist; but in other dialogues truth is divided,
as in the Laches and Protagoras, and the interest of the piece consists
in the contrast of opinions. The confusion caused by the irony of
Socrates, who, if he is true to his character, cannot say anything
of his own knowledge, is increased by the circumstance that in the
Theaetetus and some other dialogues he is occasionally playing both
parts himself, and even charging his own arguments with unfairness. In
the Theaetetus he is designedly held back from arriving at a conclusion.
For we cannot suppose that Plato conceived a definition of knowledge to
be impossible. But this is his manner of approaching and surrounding a
question. The lights which he throws on his subject are indirect, but
they are not the less real for that. He has no intention of proving a
thesis by a cut-and-dried argument; nor does he imagine that a great
philosophical problem can be tied up within the limits of a definition.
If he has analyzed a proposition or notion, even with the severity of
an impossible logic, if half-truths have been compared by him with
other half-truths, if he has cleared up or advanced popular ideas, or
illustrated a new method, his aim has been sufficiently accomplished.
The writings of Plato belong to an age in which the power of analysis
had outrun the means of knowledge; and through a spurious use of
dialectic, the distinctions which had been already 'won from the void
and formless infinite,' seemed to be rapidly returning to their original
chaos. The two great speculative philosophies, which a century earlier
had so deeply impressed the mind of Hellas, were now degenerating into
Eristic. The contemporaries of Plato and Socrates were vainly trying to
find new combinations of them, or to transfer them from the object to
the subject. The Megarians, in their first attempts to attain a severer
logic, were making knowledge impossible (compare Theaet.). They were
asserting 'the one good under many names,' and, like the Cynics, seem
to have denied predication, while the Cynics themselves were depriving
virtue of all which made virtue desirable in the eyes of Socrates and
Plato. And besides these, we find mention in the later writings of
Plato, especially in the Theaetetus, Sophist, and Laws, of certain
impenetrable godless persons, who will not believe what they 'cannot
hold in their hands'; and cannot be approached in argument, because they
cannot argue (Theat; Soph.). No school of Greek philosophers exactly
answers to these persons, in whom Plato may perhaps have blended some
features of the Atomists with the vulgar materialistic tendencies of
mankind in general (compare Introduction to the Sophist).
And not only was there a conflict of opinions, but the stage which the
mind had reached presented other difficulties hardly intelligible to
us, who live in a different cycle of human thought. All times of mental
progress are times of confusion; we only see, or rather seem to see
things clearly, when they have been long fixed and defined. In the
age of Plato, the limits of the world of imagination and of pure
abstraction, of the old world and the new, were not yet fixed. The
Greeks, in the fourth century before Christ, had no words for 'subject'
and 'object,' and no distinct conception of them; yet they were always
hovering about the question involved in them. The analysis of sense, and
the analysis of thought, were equally difficult to them; and hopelessly
confused by the attempt to solve them, not through an appeal to facts,
but by the help of general theories respecting the nature of the
universe.
Plato, in his Theaetetus, gathers up the sceptical tendencies of his
age, and compares them. But he does not seek to reconstruct out of them
a theory of knowledge. The time at which such a theory could be framed
had not yet arrived. For there was no measure of experience with which
the ideas swarming in men's minds could be compared; the meaning of
the word 'science' could scarcely be explained to them, except from the
mathematical sciences, which alone offered the type of universality and
certainty. Philosophy was becoming more and more vacant and abstract,
and not only the Platonic Ideas and the Eleatic Being, but all
abstractions seemed to be at variance with sense and at war with one
another.
The want of the Greek mind in the fourth century before Christ was
not another theory of rest or motion, or Being or atoms, but rather a
philosophy which could free the mind from the power of abstractions
and alternatives, and show how far rest and how far motion, how far the
universal principle of Being and the multitudinous principle of atoms,
entered into the composition of the world; which could distinguish
between the true and false analogy, and allow the negative as well as
the positive a place in human thought. To such a philosophy Plato, in
the Theaetetus, offers many contributions. He has followed philosophy
into the region of mythology, and pointed out the similarities of
opposing phases of thought. He has also shown that extreme abstractions
are self-destructive, and, indeed, hardly distinguishable from one
another. But his intention is not to unravel the whole subject of
knowledge, if this had been possible; and several times in the course
of the dialogue he rejects explanations of knowledge which have germs of
truth in them; as, for example, 'the resolution of the compound into the
simple;' or 'right opinion with a mark of difference.'
...
Terpsion, who has come to Megara from the country, is described as
having looked in vain for Euclides in the Agora; the latter explains
that he has been down to the harbour, and on his way thither had met
Theaetetus, who was being carried up from the army to Athens. He was
scarcely alive, for he had been badly wounded at the battle of Corinth,
and had taken the dysentery which prevailed in the camp. The mention of
his condition suggests the reflection, 'What a loss he will be!' 'Yes,
indeed,' replies Euclid; 'only just now I was hearing of his noble
conduct in the battle.' 'That I should expect; but why did he not remain
at Megara?' 'I wanted him to remain, but he would not; so I went with
him as far as Erineum; and as I parted from him, I remembered that
Socrates had seen him when he was a youth, and had a remarkable
conversation with him, not long before his own death; and he then
prophesied of him that he would be a great man if he lived.' 'How true
that has been; how like all that Socrates said! And could you repeat the
conversation?' 'Not from memory; but I took notes when I returned home,
which I afterwards filled up at leisure, and got Socrates to correct
them from time to time, when I came to Athens'...Terpsion had long
intended to ask for a sight of this writing, of which he had already
heard. They are both tired, and agree to rest and have the conversation
read to them by a servant...'Here is the roll, Terpsion; I need
only observe that I have omitted, for the sake of convenience, the
interlocutory words, "said I," "said he"; and that Theaetetus, and
Theodorus, the geometrician of Cyrene, are the persons with whom
Socrates is conversing.'
Socrates begins by asking Theodorus whether, in his visit to Athens, he
has found any Athenian youth likely to attain distinction in science.
'Yes, Socrates, there is one very remarkable youth, with whom I have
become acquainted. He is no beauty, and therefore you need not imagine
that I am in love with him; and, to say the truth, he is very like you,
for he has a snub nose, and projecting eyes, although these features are
not so marked in him as in you. He combines the most various qualities,
quickness, patience, courage; and he is gentle as well as wise, always
silently flowing on, like a river of oil. Look! he is the middle one of
those who are entering the palaestra.'
Socrates, who does not know his name, recognizes him as the son of
Euphronius, who was himself a good man and a rich. He is informed by
Theodorus that the youth is named Theaetetus, but the property of his
father has disappeared in the hands of trustees; this does not, however,
prevent him from adding liberality to his other virtues. At the desire
of Socrates he invites Theaetetus to sit by them.
'Yes,' says Socrates, 'that I may see in you, Theaetetus, the image
of my ugly self, as Theodorus declares. Not that his remark is of any
importance; for though he is a philosopher, he is not a painter, and
therefore he is no judge of our faces; but, as he is a man of science,
he may be a judge of our intellects. And if he were to praise the mental
endowments of either of us, in that case the hearer of the eulogy ought
to examine into what he says, and the subject should not refuse to be
examined.' Theaetetus consents, and is caught in a trap (compare the
similar trap which is laid for Theodorus). 'Then, Theaetetus, you will
have to be examined, for Theodorus has been praising you in a style of
which I never heard the like.' 'He was only jesting.' 'Nay, that is not
his way; and I cannot allow you, on that pretence, to retract the assent
which you have already given, or I shall make Theodorus repeat your
praises, and swear to them.' Theaetetus, in reply, professes that he is
willing to be examined, and Socrates begins by asking him what he learns
of Theodorus. He is himself anxious to learn anything of anybody; and
now he has a little question to which he wants Theaetetus or Theodorus
(or whichever of the company would not be 'donkey' to the rest) to find
an answer. Without further preface, but at the same time apologizing
for his eagerness, he asks, 'What is knowledge?' Theodorus is too old
to answer questions, and begs him to interrogate Theaetetus, who has the
advantage of youth.
Theaetetus replies, that knowledge is what he learns of Theodorus,
i.e. geometry and arithmetic; and that there are other kinds of
knowledge--shoemaking, carpentering, and the like. But Socrates rejoins,
that this answer contains too much and also too little. For although
Theaetetus has enumerated several kinds of knowledge, he has not
explained the common nature of them; as if he had been asked, 'What is
clay?' and instead of saying 'Clay is moistened earth,' he had answered,
'There is one clay of image-makers, another of potters, another of
oven-makers.' Theaetetus at once divines that Socrates means him to
extend to all kinds of knowledge the same process of generalization
which he has already learned to apply to arithmetic. For he has
discovered a division of numbers into square numbers, 4, 9, 16, etc.,
which are composed of equal factors, and represent figures which have
equal sides, and oblong numbers, 3, 5, 6, 7, etc., which are composed of
unequal factors, and represent figures which have unequal sides. But
he has never succeeded in attaining a similar conception of knowledge,
though he has often tried; and, when this and similar questions were
brought to him from Socrates, has been sorely distressed by them.
Socrates explains to him that he is in labour. For men as well as
women have pangs of labour; and both at times require the assistance of
midwives. And he, Socrates, is a midwife, although this is a secret; he
has inherited the art from his mother bold and bluff, and he ushers into
light, not children, but the thoughts of men. Like the midwives, who are
'past bearing children,' he too can have no offspring--the God will not
allow him to bring anything into the world of his own. He also reminds
Theaetetus that the midwives are or ought to be the only matchmakers
(this is the preparation for a biting jest); for those who reap the
fruit are most likely to know on what soil the plants will grow. But
respectable midwives avoid this department of practice--they do not want