PERSONS OF THE DIALOGUE: Socrates,
Euclid and Terpsion meet in front of
Euclid's house in Megara; they enter the house, and the dialogue is
read to them by a servant.
EUCLID: Have you only just arrived
from the country, Terpsion?
TERPSION: No, I came some time ago:
and I have been in the Agora looking for you, and wondering that I
could not find you.
EUCLID: But I was not in the city.
TERPSION: Where then?
EUCLID: As I was going down to the
harbour, I met Theaetetus—he was being carried up to Athens from the
army at Corinth.
TERPSION: Was he alive or dead?
EUCLID: He was scarcely alive, for
he has been badly wounded; but he was suffering even more from the
sickness which has broken out in the army.
TERPSION: The dysentery, you mean?
TERPSION: Alas! what a loss he will
EUCLID: Yes, Terpsion, he is a noble
fellow; only to-day I heard some people highly praising his behaviour
in this very battle.
TERPSION: No wonder; I should rather
be surprised at hearing anything else of him. But why did he go on,
instead of stopping at Megara?
EUCLID: He wanted to get home:
although I entreated and advised him to remain, he would not listen to
me; so I set him on his way, and turned back, and then I remembered
what Socrates had said of him, and thought how remarkably this, like
all his predictions, had been fulfilled. I believe that he had seen him
a little before his own death, when Theaetetus was a youth, and he had
a memorable conversation with him, which he repeated to me when I came
to Athens; he was full of admiration of his genius, and said that he
would most certainly be a great man, if he lived.
TERPSION: The prophecy has certainly
been fulfilled; but what was the conversation? can you tell me?
EUCLID: No, indeed, not offhand; but
I took notes of it as soon as I got home; these I filled up from
memory, writing them out at leisure; and whenever I went to Athens, I
asked Socrates about any point which I had forgotten, and on my return
I made corrections; thus I have nearly the whole conversation written
TERPSION: I remember—you told me;
and I have always been intending to ask you to show me the writing, but
have put off doing so; and now, why should we not read it
through?—having just come from the country, I should greatly like to
EUCLID: I too shall be very glad of
a rest, for I went with Theaetetus as far as Erineum. Let us go in,
then, and, while we are reposing, the servant shall read to us.
TERPSION: Very good.
EUCLID: Here is the roll, Terpsion;
I may observe that I have introduced Socrates, not as narrating to me,
but as actually conversing with the persons whom he mentioned—these
were, Theodorus the geometrician (of Cyrene), and Theaetetus. I have
omitted, for the sake of convenience, the interlocutory words 'I said,'
'I remarked,' which he used when he spoke of himself, and again, 'he
agreed,' or 'disagreed,' in the answer, lest the repetition of them
should be troublesome.
TERPSION: Quite right, Euclid.
EUCLID: And now, boy, you may take
the roll and read.
EUCLID'S SERVANT READS.
SOCRATES: If I cared enough about
the Cyrenians, Theodorus, I would ask you whether there are any rising
geometricians or philosophers in that part of the world. But I am more
interested in our own Athenian youth, and I would rather know who among
them are likely to do well. I observe them as far as I can myself, and
I enquire of any one whom they follow, and I see that a great many of
them follow you, in which they are quite right, considering your
eminence in geometry and in other ways. Tell me then, if you have met
with any one who is good for anything.
THEODORUS: Yes, Socrates, I have
become acquainted with one very remarkable Athenian youth, whom I
commend to you as well worthy of your attention. If he had been a
beauty I should have been afraid to praise him, lest you should suppose
that I was in love with him; but he is no beauty, and you must not be
offended if I say that he is very like you; for he has a snub nose and
projecting eyes, although these features are less marked in him than in
you. Seeing, then, that he has no personal attractions, I may freely
say, that in all my acquaintance, which is very large, I never knew any
one who was his equal in natural gifts: for he has a quickness of
apprehension which is almost unrivalled, and he is exceedingly gentle,
and also the most courageous of men; there is a union of qualities in
him such as I have never seen in any other, and should scarcely have
thought possible; for those who, like him, have quick and ready and
retentive wits, have generally also quick tempers; they are ships
without ballast, and go darting about, and are mad rather than
courageous; and the steadier sort, when they have to face study, prove
stupid and cannot remember. Whereas he moves surely and smoothly and
successfully in the path of knowledge and enquiry; and he is full of
gentleness, flowing on silently like a river of oil; at his age, it is
SOCRATES: That is good news; whose
son is he?
THEODORUS: The name of his father I
have forgotten, but the youth himself is the middle one of those who
are approaching us; he and his companions have been anointing
themselves in the outer court, and now they seem to have finished, and
are coming towards us. Look and see whether you know him.
SOCRATES: I know the youth, but I do
not know his name; he is the son of Euphronius the Sunian, who was
himself an eminent man, and such another as his son is, according to
your account of him; I believe that he left a considerable fortune.
THEODORUS: Theaetetus, Socrates, is
his name; but I rather think that the property disappeared in the hands
of trustees; notwithstanding which he is wonderfully liberal.
SOCRATES: He must be a fine fellow;
tell him to come and sit by me.
THEODORUS: I will. Come hither,
Theaetetus, and sit by Socrates.
SOCRATES: By all means, Theaetetus,
in order that I may see the reflection of myself in your face, for
Theodorus says that we are alike; and yet if each of us held in his
hands a lyre, and he said that they were tuned alike, should we at once
take his word, or should we ask whether he who said so was or was not a
THEAETETUS: We should ask.
SOCRATES: And if we found that he
was, we should take his word; and if not, not?
SOCRATES: And if this supposed
likeness of our faces is a matter of any interest to us, we should
enquire whether he who says that we are alike is a painter or not?
THEAETETUS: Certainly we should.
SOCRATES: And is Theodorus a
THEAETETUS: I never heard that he
SOCRATES: Is he a geometrician?
THEAETETUS: Of course he is,
SOCRATES: And is he an astronomer
and calculator and musician, and in general an educated man?
THEAETETUS: I think so.
SOCRATES: If, then, he remarks on a
similarity in our persons, either by way of praise or blame, there is
no particular reason why we should attend to him.
THEAETETUS: I should say not.
SOCRATES: But if he praises the
virtue or wisdom which are the mental endowments of either of us, then
he who hears the praises will naturally desire to examine him who is
praised: and he again should be willing to exhibit himself.
THEAETETUS: Very true, Socrates.
SOCRATES: Then now is the time, my
dear Theaetetus, for me to examine, and for you to exhibit; since
although Theodorus has praised many a citizen and stranger in my
hearing, never did I hear him praise any one as he has been praising
THEAETETUS: I am glad to hear it,
Socrates; but what if he was only in jest?
SOCRATES: Nay, Theodorus is not
given to jesting; and I cannot allow you to retract your consent on any
such pretence as that. If you do, he will have to swear to his words;
and we are perfectly sure that no one will be found to impugn him. Do
not be shy then, but stand to your word.
THEAETETUS: I suppose I must, if you
SOCRATES: In the first place, I
should like to ask what you learn of Theodorus: something of geometry,
SOCRATES: And astronomy and harmony
THEAETETUS: I do my best.
SOCRATES: Yes, my boy, and so do I;
and my desire is to learn of him, or of anybody who seems to understand
these things. And I get on pretty well in general; but there is a
little difficulty which I want you and the company to aid me in
investigating. Will you answer me a question: 'Is not learning growing
wiser about that which you learn?'
THEAETETUS: Of course.
SOCRATES: And by wisdom the wise are
SOCRATES: And is that different in
any way from knowledge?
SOCRATES: Wisdom; are not men wise
in that which they know?
THEAETETUS: Certainly they are.
SOCRATES: Then wisdom and knowledge
are the same?
SOCRATES: Herein lies the difficulty
which I can never solve to my satisfaction—What is knowledge? Can we
answer that question? What say you? which of us will speak first?
whoever misses shall sit down, as at a game of ball, and shall be
donkey, as the boys say; he who lasts out his competitors in the game
without missing, shall be our king, and shall have the right of putting
to us any questions which he pleases...Why is there no reply? I hope,
Theodorus, that I am not betrayed into rudeness by my love of
conversation? I only want to make us talk and be friendly and sociable.
THEODORUS: The reverse of rudeness,
Socrates: but I would rather that you would ask one of the young
fellows; for the truth is, that I am unused to your game of question
and answer, and I am too old to learn; the young will be more suitable,
and they will improve more than I shall, for youth is always able to
improve. And so having made a beginning with Theaetetus, I would advise
you to go on with him and not let him off.
SOCRATES: Do you hear, Theaetetus,
what Theodorus says? The philosopher, whom you would not like to
disobey, and whose word ought to be a command to a young man, bids me
interrogate you. Take courage, then, and nobly say what you think that
THEAETETUS: Well, Socrates, I will
answer as you and he bid me; and if I make a mistake, you will
doubtless correct me.
SOCRATES: We will, if we can.
THEAETETUS: Then, I think that the
sciences which I learn from Theodorus—geometry, and those which you
just now mentioned—are knowledge; and I would include the art of the
cobbler and other craftsmen; these, each and all of, them, are
SOCRATES: Too much, Theaetetus, too
much; the nobility and liberality of your nature make you give many and
diverse things, when I am asking for one simple thing.
THEAETETUS: What do you mean,
SOCRATES: Perhaps nothing. I will
endeavour, however, to explain what I believe to be my meaning: When
you speak of cobbling, you mean the art or science of making shoes?
THEAETETUS: Just so.
SOCRATES: And when you speak of
carpentering, you mean the art of making wooden implements?
THEAETETUS: I do.
SOCRATES: In both cases you define
the subject matter of each of the two arts?
SOCRATES: But that, Theaetetus, was
not the point of my question: we wanted to know not the subjects, nor
yet the number of the arts or sciences, for we were not going to count
them, but we wanted to know the nature of knowledge in the abstract. Am
I not right?
THEAETETUS: Perfectly right.
SOCRATES: Let me offer an
illustration: Suppose that a person were to ask about some very trivial
and obvious thing—for example, What is clay? and we were to reply, that
there is a clay of potters, there is a clay of oven-makers, there is a
clay of brick-makers; would not the answer be ridiculous?
SOCRATES: In the first place, there
would be an absurdity in assuming that he who asked the question would
understand from our answer the nature of 'clay,' merely because we
added 'of the image-makers,' or of any other workers. How can a man
understand the name of anything, when he does not know the nature of
THEAETETUS: He cannot.
SOCRATES: Then he who does not know
what science or knowledge is, has no knowledge of the art or science of
SOCRATES: Nor of any other science?
SOCRATES: And when a man is asked
what science or knowledge is, to give in answer the name of some art or
science is ridiculous; for the question is, 'What is knowledge?' and he
replies, 'A knowledge of this or that.'
SOCRATES: Moreover, he might answer
shortly and simply, but he makes an enormous circuit. For example, when
asked about the clay, he might have said simply, that clay is moistened
earth—what sort of clay is not to the point.
THEAETETUS: Yes, Socrates, there is
no difficulty as you put the question. You mean, if I am not mistaken,
something like what occurred to me and to my friend here, your namesake
Socrates, in a recent discussion.
SOCRATES: What was that, Theaetetus?
THEAETETUS: Theodorus was writing
out for us something about roots, such as the roots of three or five,
showing that they are incommensurable by the unit: he selected other
examples up to seventeen—there he stopped. Now as there are innumerable
roots, the notion occurred to us of attempting to include them all
under one name or class.
SOCRATES: And did you find such a
THEAETETUS: I think that we did; but
I should like to have your opinion.
SOCRATES: Let me hear.
THEAETETUS: We divided all numbers
into two classes: those which are made up of equal factors multiplying
into one another, which we compared to square figures and called square
or equilateral numbers;—that was one class.
SOCRATES: Very good.
THEAETETUS: The intermediate
numbers, such as three and five, and every other number which is made
up of unequal factors, either of a greater multiplied by a less, or of
a less multiplied by a greater, and when regarded as a figure, is
contained in unequal sides;—all these we compared to oblong figures,
and called them oblong numbers.
SOCRATES: Capital; and what
THEAETETUS: The lines, or sides,
which have for their squares the equilateral plane numbers, were called
by us lengths or magnitudes; and the lines which are the roots of (or
whose squares are equal to) the oblong numbers, were called powers or
roots; the reason of this latter name being, that they are
commensurable with the former [i.e., with the so-called lengths or
magnitudes] not in linear measurement, but in the value of the
superficial content of their squares; and the same about solids.
SOCRATES: Excellent, my boys; I
think that you fully justify the praises of Theodorus, and that he will
not be found guilty of false witness.
THEAETETUS: But I am unable,
Socrates, to give you a similar answer about knowledge, which is what
you appear to want; and therefore Theodorus is a deceiver after all.
SOCRATES: Well, but if some one were
to praise you for running, and to say that he never met your equal
among boys, and afterwards you were beaten in a race by a grown-up man,
who was a great runner—would the praise be any the less true?
THEAETETUS: Certainly not.
SOCRATES: And is the discovery of
the nature of knowledge so small a matter, as just now said? Is it not
one which would task the powers of men perfect in every way?
THEAETETUS: By heaven, they should
be the top of all perfection!
SOCRATES: Well, then, be of good
cheer; do not say that Theodorus was mistaken about you, but do your
best to ascertain the true nature of knowledge, as well as of other
THEAETETUS: I am eager enough,
Socrates, if that would bring to light the truth.
SOCRATES: Come, you made a good
beginning just now; let your own answer about roots be your model, and
as you comprehended them all in one class, try and bring the many sorts
of knowledge under one definition.
THEAETETUS: I can assure you,
Socrates, that I have tried very often, when the report of questions
asked by you was brought to me; but I can neither persuade myself that
I have a satisfactory answer to give, nor hear of any one who answers
as you would have him; and I cannot shake off a feeling of anxiety.
SOCRATES: These are the pangs of
labour, my dear Theaetetus; you have something within you which you are
bringing to the birth.
THEAETETUS: I do not know, Socrates;
I only say what I feel.
SOCRATES: And have you never heard,
simpleton, that I am the son of a midwife, brave and burly, whose name
THEAETETUS: Yes, I have.
SOCRATES: And that I myself practise
THEAETETUS: No, never.
SOCRATES: Let me tell you that I do
though, my friend: but you must not reveal the secret, as the world in
general have not found me out; and therefore they only say of me, that
I am the strangest of mortals and drive men to their wits' end. Did you
ever hear that too?
SOCRATES: Shall I tell you the
THEAETETUS: By all means.
SOCRATES: Bear in mind the whole
business of the midwives, and then you will see my meaning better:—No
woman, as you are probably aware, who is still able to conceive and
bear, attends other women, but only those who are past bearing.
THEAETETUS: Yes, I know.
SOCRATES: The reason of this is said
to be that Artemis—the goddess of childbirth—is not a mother, and she
honours those who are like herself; but she could not allow the barren
to be midwives, because human nature cannot know the mystery of an art
without experience; and therefore she assigned this office to those who
are too old to bear.
THEAETETUS: I dare say.
SOCRATES: And I dare say too, or
rather I am absolutely certain, that the midwives know better than
others who is pregnant and who is not?
THEAETETUS: Very true.
SOCRATES: And by the use of potions
and incantations they are able to arouse the pangs and to soothe them
at will; they can make those bear who have a difficulty in bearing, and
if they think fit they can smother the embryo in the womb.
THEAETETUS: They can.
SOCRATES: Did you ever remark that
they are also most cunning matchmakers, and have a thorough knowledge
of what unions are likely to produce a brave brood?
THEAETETUS: No, never.
SOCRATES: Then let me tell you that
this is their greatest pride, more than cutting the umbilical cord. And
if you reflect, you will see that the same art which cultivates and
gathers in the fruits of the earth, will be most likely to know in what
soils the several plants or seeds should be deposited.
THEAETETUS: Yes, the same art.
SOCRATES: And do you suppose that
with women the case is otherwise?
THEAETETUS: I should think not.
SOCRATES: Certainly not; but
midwives are respectable women who have a character to lose, and they
avoid this department of their profession, because they are afraid of
being called procuresses, which is a name given to those who join
together man and woman in an unlawful and unscientific way; and yet the
true midwife is also the true and only matchmaker.
SOCRATES: Such are the midwives,
whose task is a very important one, but not so important as mine; for
women do not bring into the world at one time real children, and at
another time counterfeits which are with difficulty distinguished from
them; if they did, then the discernment of the true and false birth
would be the crowning achievement of the art of midwifery—you would
THEAETETUS: Indeed I should.
SOCRATES: Well, my art of midwifery
is in most respects like theirs; but differs, in that I attend men and
not women; and look after their souls when they are in labour, and not
after their bodies: and the triumph of my art is in thoroughly
examining whether the thought which the mind of the young man brings
forth is a false idol or a noble and true birth. And like the midwives,
I am barren, and the reproach which is often made against me, that I
ask questions of others and have not the wit to answer them myself, is
very just—the reason is, that the god compels me to be a midwife, but
does not allow me to bring forth. And therefore I am not myself at all
wise, nor have I anything to show which is the invention or birth of my
own soul, but those who converse with me profit. Some of them appear
dull enough at first, but afterwards, as our acquaintance ripens, if
the god is gracious to them, they all make astonishing progress; and
this in the opinion of others as well as in their own. It is quite dear
that they never learned anything from me; the many fine discoveries to
which they cling are of their own making. But to me and the god they
owe their delivery. And the proof of my words is, that many of them in
their ignorance, either in their self-conceit despising me, or falling
under the influence of others, have gone away too soon; and have not
only lost the children of whom I had previously delivered them by an
ill bringing up, but have stifled whatever else they had in them by
evil communications, being fonder of lies and shams than of the truth;
and they have at last ended by seeing themselves, as others see them,
to be great fools. Aristeides, the son of Lysimachus, is one of them,
and there are many others. The truants often return to me, and beg that
I would consort with them again—they are ready to go to me on their
knees—and then, if my familiar allows, which is not always the case, I
receive them, and they begin to grow again. Dire are the pangs which my
art is able to arouse and to allay in those who consort with me, just
like the pangs of women in childbirth; night and day they are full of
perplexity and travail which is even worse than that of the women. So
much for them. And there are others, Theaetetus, who come to me
apparently having nothing in them; and as I know that they have no need
of my art, I coax them into marrying some one, and by the grace of God
I can generally tell who is likely to do them good. Many of them I have
given away to Prodicus, and many to other inspired sages. I tell you
this long story, friend Theaetetus, because I suspect, as indeed you
seem to think yourself, that you are in labour—great with some
conception. Come then to me, who am a midwife's son and myself a
midwife, and do your best to answer the questions which I will ask you.
And if I abstract and expose your first-born, because I discover upon
inspection that the conception which you have formed is a vain shadow,
do not quarrel with me on that account, as the manner of women is when
their first children are taken from them. For I have actually known
some who were ready to bite me when I deprived them of a darling folly;
they did not perceive that I acted from goodwill, not knowing that no
god is the enemy of man—that was not within the range of their ideas;
neither am I their enemy in all this, but it would be wrong for me to
admit falsehood, or to stifle the truth. Once more, then, Theaetetus, I
repeat my old question, 'What is knowledge?'—and do not say that you
cannot tell; but quit yourself like a man, and by the help of God you
will be able to tell.
THEAETETUS: At any rate, Socrates,
after such an exhortation I should be ashamed of not trying to do my
best. Now he who knows perceives what he knows, and, as far as I can
see at present, knowledge is perception.
SOCRATES: Bravely said, boy; that is
the way in which you should express your opinion. And now, let us
examine together this conception of yours, and see whether it is a true
birth or a mere wind-egg:—You say that knowledge is perception?
SOCRATES: Well, you have delivered
yourself of a very important doctrine about knowledge; it is indeed the
opinion of Protagoras, who has another way of expressing it. Man, he
says, is the measure of all things, of the existence of things that
are, and of the non-existence of things that are not:—You have read
THEAETETUS: O yes, again and again.
SOCRATES: Does he not say that
things are to you such as they appear to you, and to me such as they
appear to me, and that you and I are men?
THEAETETUS: Yes, he says so.
SOCRATES: A wise man is not likely
to talk nonsense. Let us try to understand him: the same wind is
blowing, and yet one of us may be cold and the other not, or one may be
slightly and the other very cold?
THEAETETUS: Quite true.
SOCRATES: Now is the wind, regarded
not in relation to us but absolutely, cold or not; or are we to say,
with Protagoras, that the wind is cold to him who is cold, and not to
him who is not?
THEAETETUS: I suppose the last.
SOCRATES: Then it must appear so to
each of them?
SOCRATES: And 'appears to him' means
the same as 'he perceives.'
SOCRATES: Then appearing and
perceiving coincide in the case of hot and cold, and in similar
instances; for things appear, or may be supposed to be, to each one
such as he perceives them?
SOCRATES: Then perception is always
of existence, and being the same as knowledge is unerring?
SOCRATES: In the name of the Graces,
what an almighty wise man Protagoras must have been! He spoke these
things in a parable to the common herd, like you and me, but told the
truth, 'his Truth,' (In allusion to a book of Protagoras' which bore
this title.) in secret to his own disciples.
THEAETETUS: What do you mean,
SOCRATES: I am about to speak of a
high argument, in which all things are said to be relative; you cannot
rightly call anything by any name, such as great or small, heavy or
light, for the great will be small and the heavy light—there is no
single thing or quality, but out of motion and change and admixture all
things are becoming relatively to one another, which 'becoming' is by
us incorrectly called being, but is really becoming, for nothing ever
is, but all things are becoming. Summon all philosophers—Protagoras,
Heracleitus, Empedocles, and the rest of them, one after another, and
with the exception of Parmenides they will agree with you in this.
Summon the great masters of either kind of poetry—Epicharmus, the
prince of Comedy, and Homer of Tragedy; when the latter sings of
'Ocean whence sprang the gods, and
does he not mean that all things are
the offspring, of flux and motion?
THEAETETUS: I think so.
SOCRATES: And who could take up arms
against such a great army having Homer for its general, and not appear
ridiculous? (Compare Cratylus.)
THEAETETUS: Who indeed, Socrates?
SOCRATES: Yes, Theaetetus; and there
are plenty of other proofs which will show that motion is the source of
what is called being and becoming, and inactivity of not-being and
destruction; for fire and warmth, which are supposed to be the parent
and guardian of all other things, are born of movement and of friction,
which is a kind of motion;—is not this the origin of fire?
THEAETETUS: It is.
SOCRATES: And the race of animals is
generated in the same way?
SOCRATES: And is not the bodily
habit spoiled by rest and idleness, but preserved for a long time by
motion and exercise?
SOCRATES: And what of the mental
habit? Is not the soul informed, and improved, and preserved by study
and attention, which are motions; but when at rest, which in the soul
only means want of attention and study, is uninformed, and speedily
forgets whatever she has learned?
SOCRATES: Then motion is a good, and
rest an evil, to the soul as well as to the body?
SOCRATES: I may add, that breathless
calm, stillness and the like waste and impair, while wind and storm
preserve; and the palmary argument of all, which I strongly urge, is
the golden chain in Homer, by which he means the sun, thereby
indicating that so long as the sun and the heavens go round in their
orbits, all things human and divine are and are preserved, but if they
were chained up and their motions ceased, then all things would be
destroyed, and, as the saying is, turned upside down.
THEAETETUS: I believe, Socrates,
that you have truly explained his meaning.
SOCRATES: Then now apply his
doctrine to perception, my good friend, and first of all to vision;
that which you call white colour is not in your eyes, and is not a
distinct thing which exists out of them. And you must not assign any
place to it: for if it had position it would be, and be at rest, and
there would be no process of becoming.
THEAETETUS: Then what is colour?
SOCRATES: Let us carry the principle
which has just been affirmed, that nothing is self-existent, and then
we shall see that white, black, and every other colour, arises out of
the eye meeting the appropriate motion, and that what we call a colour
is in each case neither the active nor the passive element, but
something which passes between them, and is peculiar to each
percipient; are you quite certain that the several colours appear to a
dog or to any animal whatever as they appear to you?
THEAETETUS: Far from it.
SOCRATES: Or that anything appears
the same to you as to another man? Are you so profoundly convinced of
this? Rather would it not be true that it never appears exactly the
same to you, because you are never exactly the same?
THEAETETUS: The latter.
SOCRATES: And if that with which I
compare myself in size, or which I apprehend by touch, were great or
white or hot, it could not become different by mere contact with
another unless it actually changed; nor again, if the comparing or
apprehending subject were great or white or hot, could this, when
unchanged from within, become changed by any approximation or affection
of any other thing. The fact is that in our ordinary way of speaking we
allow ourselves to be driven into most ridiculous and wonderful
contradictions, as Protagoras and all who take his line of argument
THEAETETUS: How? and of what sort do
SOCRATES: A little instance will
sufficiently explain my meaning: Here are six dice, which are more by a
half when compared with four, and fewer by a half than twelve—they are
more and also fewer. How can you or any one maintain the contrary?
THEAETETUS: Very true.
SOCRATES: Well, then, suppose that
Protagoras or some one asks whether anything can become greater or more
if not by increasing, how would you answer him, Theaetetus?
THEAETETUS: I should say 'No,'
Socrates, if I were to speak my mind in reference to this last
question, and if I were not afraid of contradicting my former answer.
SOCRATES: Capital! excellent! spoken
like an oracle, my boy! And if you reply 'Yes,' there will be a case
for Euripides; for our tongue will be unconvinced, but not our mind.
(In allusion to the well-known line of Euripides, Hippol.: e gloss
omomoch e de thren anomotos.)
THEAETETUS: Very true.
SOCRATES: The thoroughbred Sophists,
who know all that can be known about the mind, and argue only out of
the superfluity of their wits, would have had a regular sparring-match
over this, and would have knocked their arguments together finely. But
you and I, who have no professional aims, only desire to see what is
the mutual relation of these principles,—whether they are consistent
with each or not.
THEAETETUS: Yes, that would be my
SOCRATES: And mine too. But since
this is our feeling, and there is plenty of time, why should we not
calmly and patiently review our own thoughts, and thoroughly examine
and see what these appearances in us really are? If I am not mistaken,
they will be described by us as follows:—first, that nothing can become
greater or less, either in number or magnitude, while remaining equal
to itself—you would agree?
SOCRATES: Secondly, that without
addition or subtraction there is no increase or diminution of anything,
but only equality.
THEAETETUS: Quite true.
SOCRATES: Thirdly, that what was not
before cannot be afterwards, without becoming and having become.
THEAETETUS: Yes, truly.
SOCRATES: These three axioms, if I
am not mistaken, are fighting with one another in our minds in the case
of the dice, or, again, in such a case as this—if I were to say that I,
who am of a certain height and taller than you, may within a year,
without gaining or losing in height, be not so tall—not that I should
have lost, but that you would have increased. In such a case, I am
afterwards what I once was not, and yet I have not become; for I could
not have become without becoming, neither could I have become less
without losing somewhat of my height; and I could give you ten thousand
examples of similar contradictions, if we admit them at all. I believe
that you follow me, Theaetetus; for I suspect that you have thought of
these questions before now.
THEAETETUS: Yes, Socrates, and I am
amazed when I think of them; by the Gods I am! and I want to know what
on earth they mean; and there are times when my head quite swims with
the contemplation of them.
SOCRATES: I see, my dear Theaetetus,
that Theodorus had a true insight into your nature when he said that
you were a philosopher, for wonder is the feeling of a philosopher, and
philosophy begins in wonder. He was not a bad genealogist who said that
Iris (the messenger of heaven) is the child of Thaumas (wonder). But do
you begin to see what is the explanation of this perplexity on the
hypothesis which we attribute to Protagoras?
THEAETETUS: Not as yet.
SOCRATES: Then you will be obliged
to me if I help you to unearth the hidden 'truth' of a famous man or
THEAETETUS: To be sure, I shall be
very much obliged.
SOCRATES: Take a look round, then,
and see that none of the uninitiated are listening. Now by the
uninitiated I mean the people who believe in nothing but what they can
grasp in their hands, and who will not allow that action or generation
or anything invisible can have real existence.
THEAETETUS: Yes, indeed, Socrates,
they are very hard and impenetrable mortals.
SOCRATES: Yes, my boy, outer
barbarians. Far more ingenious are the brethren whose mysteries I am
about to reveal to you. Their first principle is, that all is motion,
and upon this all the affections of which we were just now speaking are
supposed to depend: there is nothing but motion, which has two forms,
one active and the other passive, both in endless number; and out of
the union and friction of them there is generated a progeny endless in
number, having two forms, sense and the object of sense, which are ever
breaking forth and coming to the birth at the same moment. The senses
are variously named hearing, seeing, smelling; there is the sense of
heat, cold, pleasure, pain, desire, fear, and many more which have
names, as well as innumerable others which are without them; each has
its kindred object,—each variety of colour has a corresponding variety
of sight, and so with sound and hearing, and with the rest of the
senses and the objects akin to them. Do you see, Theaetetus, the
bearings of this tale on the preceding argument?
THEAETETUS: Indeed I do not.
SOCRATES: Then attend, and I will
try to finish the story. The purport is that all these things are in
motion, as I was saying, and that this motion is of two kinds, a slower
and a quicker; and the slower elements have their motions in the same
place and with reference to things near them, and so they beget; but
what is begotten is swifter, for it is carried to fro, and moves from
place to place. Apply this to sense:—When the eye and the appropriate
object meet together and give birth to whiteness and the sensation
connatural with it, which could not have been given by either of them
going elsewhere, then, while the sight is flowing from the eye,
whiteness proceeds from the object which combines in producing the
colour; and so the eye is fulfilled with sight, and really sees, and
becomes, not sight, but a seeing eye; and the object which combined to
form the colour is fulfilled with whiteness, and becomes not whiteness
but a white thing, whether wood or stone or whatever the object may be
which happens to be coloured white. And this is true of all sensible
objects, hard, warm, and the like, which are similarly to be regarded,
as I was saying before, not as having any absolute existence, but as
being all of them of whatever kind generated by motion in their
intercourse with one another; for of the agent and patient, as existing
in separation, no trustworthy conception, as they say, can be formed,
for the agent has no existence until united with the patient, and the
patient has no existence until united with the agent; and that which by
uniting with something becomes an agent, by meeting with some other
thing is converted into a patient. And from all these considerations,
as I said at first, there arises a general reflection, that there is no
one self-existent thing, but everything is becoming and in relation;
and being must be altogether abolished, although from habit and
ignorance we are compelled even in this discussion to retain the use of
the term. But great philosophers tell us that we are not to allow
either the word 'something,' or 'belonging to something,' or 'to me,'
or 'this,' or 'that,' or any other detaining name to be used, in the
language of nature all things are being created and destroyed, coming
into being and passing into new forms; nor can any name fix or detain
them; he who attempts to fix them is easily refuted. And this should be
the way of speaking, not only of particulars but of aggregates; such
aggregates as are expressed in the word 'man,' or 'stone,' or any name
of an animal or of a class. O Theaetetus, are not these speculations
sweet as honey? And do you not like the taste of them in the mouth?
THEAETETUS: I do not know what to
say, Socrates; for, indeed, I cannot make out whether you are giving
your own opinion or only wanting to draw me out.
SOCRATES: You forget, my friend,
that I neither know, nor profess to know, anything of these matters;
you are the person who is in labour, I am the barren midwife; and this
is why I soothe you, and offer you one good thing after another, that
you may taste them. And I hope that I may at last help to bring your
own opinion into the light of day: when this has been accomplished,
then we will determine whether what you have brought forth is only a
wind-egg or a real and genuine birth. Therefore, keep up your spirits,
and answer like a man what you think.
THEAETETUS: Ask me.
SOCRATES: Then once more: Is it your
opinion that nothing is but what becomes?—the good and the noble, as
well as all the other things which we were just now mentioning?
THEAETETUS: When I hear you
discoursing in this style, I think that there is a great deal in what
you say, and I am very ready to assent.
SOCRATES: Let us not leave the
argument unfinished, then; for there still remains to be considered an
objection which may be raised about dreams and diseases, in particular
about madness, and the various illusions of hearing and sight, or of
other senses. For you know that in all these cases the esse-percipi
theory appears to be unmistakably refuted, since in dreams and
illusions we certainly have false perceptions; and far from saying that
everything is which appears, we should rather say that nothing is which
THEAETETUS: Very true, Socrates.
SOCRATES: But then, my boy, how can
any one contend that knowledge is perception, or that to every man what
THEAETETUS: I am afraid to say,
Socrates, that I have nothing to answer, because you rebuked me just
now for making this excuse; but I certainly cannot undertake to argue
that madmen or dreamers think truly, when they imagine, some of them
that they are gods, and others that they can fly, and are flying in
SOCRATES: Do you see another
question which can be raised about these phenomena, notably about
dreaming and waking?
THEAETETUS: What question?
SOCRATES: A question which I think
that you must often have heard persons ask:—How can you determine
whether at this moment we are sleeping, and all our thoughts are a
dream; or whether we are awake, and talking to one another in the
THEAETETUS: Indeed, Socrates, I do
not know how to prove the one any more than the other, for in both
cases the facts precisely correspond;—and there is no difficulty in
supposing that during all this discussion we have been talking to one
another in a dream; and when in a dream we seem to be narrating dreams,
the resemblance of the two states is quite astonishing.
SOCRATES: You see, then, that a
doubt about the reality of sense is easily raised, since there may even
be a doubt whether we are awake or in a dream. And as our time is
equally divided between sleeping and waking, in either sphere of
existence the soul contends that the thoughts which are present to our
minds at the time are true; and during one half of our lives we affirm
the truth of the one, and, during the other half, of the other; and are
equally confident of both.
THEAETETUS: Most true.
SOCRATES: And may not the same be
said of madness and other disorders? the difference is only that the
times are not equal.
SOCRATES: And is truth or falsehood
to be determined by duration of time?
THEAETETUS: That would be in many
SOCRATES: But can you certainly
determine by any other means which of these opinions is true?
THEAETETUS: I do not think that I
SOCRATES: Listen, then, to a
statement of the other side of the argument, which is made by the
champions of appearance. They would say, as I imagine—Can that which is
wholly other than something, have the same quality as that from which
it differs? and observe, Theaetetus, that the word 'other' means not
'partially,' but 'wholly other.'
THEAETETUS: Certainly, putting the
question as you do, that which is wholly other cannot either
potentially or in any other way be the same.
SOCRATES: And must therefore be
admitted to be unlike?
SOCRATES: If, then, anything happens
to become like or unlike itself or another, when it becomes like we
call it the same—when unlike, other?
SOCRATES: Were we not saying that
there are agents many and infinite, and patients many and infinite?
SOCRATES: And also that different
combinations will produce results which are not the same, but
SOCRATES: Let us take you and me, or
anything as an example:—There is Socrates in health, and Socrates
sick—Are they like or unlike?
THEAETETUS: You mean to compare
Socrates in health as a whole, and Socrates in sickness as a whole?
SOCRATES: Exactly; that is my
THEAETETUS: I answer, they are
SOCRATES: And if unlike, they are
SOCRATES: And would you not say the
same of Socrates sleeping and waking, or in any of the states which we
THEAETETUS: I should.
SOCRATES: All agents have a
different patient in Socrates, accordingly as he is well or ill.
THEAETETUS: Of course.
SOCRATES: And I who am the patient,
and that which is the agent, will produce something different in each
of the two cases?
SOCRATES: The wine which I drink
when I am in health, appears sweet and pleasant to me?
SOCRATES: For, as has been already
acknowledged, the patient and agent meet together and produce sweetness
and a perception of sweetness, which are in simultaneous motion, and
the perception which comes from the patient makes the tongue
percipient, and the quality of sweetness which arises out of and is
moving about the wine, makes the wine both to be and to appear sweet to
the healthy tongue.
THEAETETUS: Certainly; that has been
SOCRATES: But when I am sick, the
wine really acts upon another and a different person?
SOCRATES: The combination of the
draught of wine, and the Socrates who is sick, produces quite another
result; which is the sensation of bitterness in the tongue, and the
motion and creation of bitterness in and about the wine, which becomes
not bitterness but something bitter; as I myself become not perception
SOCRATES: There is no other object
of which I shall ever have the same perception, for another object
would give another perception, and would make the percipient other and
different; nor can that object which affects me, meeting another
subject, produce the same, or become similar, for that too would
produce another result from another subject, and become different.
SOCRATES: Neither can I by myself,
have this sensation, nor the object by itself, this quality.
THEAETETUS: Certainly not.
SOCRATES: When I perceive I must
become percipient of something—there can be no such thing as perceiving
and perceiving nothing; the object, whether it become sweet, bitter, or
of any other quality, must have relation to a percipient; nothing can
become sweet which is sweet to no one.
THEAETETUS: Certainly not.
SOCRATES: Then the inference is,
that we (the agent and patient) are or become in relation to one
another; there is a law which binds us one to the other, but not to any
other existence, nor each of us to himself; and therefore we can only
be bound to one another; so that whether a person says that a thing is
or becomes, he must say that it is or becomes to or of or in relation
to something else; but he must not say or allow any one else to say
that anything is or becomes absolutely:—such is our conclusion.
THEAETETUS: Very true, Socrates.
SOCRATES: Then, if that which acts
upon me has relation to me and to no other, I and no other am the
percipient of it?
THEAETETUS: Of course.
SOCRATES: Then my perception is true
to me, being inseparable from my own being; and, as Protagoras says, to
myself I am judge of what is and what is not to me.
THEAETETUS: I suppose so.
SOCRATES: How then, if I never err,
and if my mind never trips in the conception of being or becoming, can
I fail of knowing that which I perceive?
THEAETETUS: You cannot.
SOCRATES: Then you were quite right
in affirming that knowledge is only perception; and the meaning turns
out to be the same, whether with Homer and Heracleitus, and all that
company, you say that all is motion and flux, or with the great sage
Protagoras, that man is the measure of all things; or with Theaetetus,
that, given these premises, perception is knowledge. Am I not right,
Theaetetus, and is not this your new-born child, of which I have
delivered you? What say you?
THEAETETUS: I cannot but agree,
SOCRATES: Then this is the child,
however he may turn out, which you and I have with difficulty brought
into the world. And now that he is born, we must run round the hearth
with him, and see whether he is worth rearing, or is only a wind-egg
and a sham. Is he to be reared in any case, and not exposed? or will
you bear to see him rejected, and not get into a passion if I take away
THEODORUS: Theaetetus will not be
angry, for he is very good-natured. But tell me, Socrates, in heaven's
name, is this, after all, not the truth?
SOCRATES: You, Theodorus, are a
lover of theories, and now you innocently fancy that I am a bag full of
them, and can easily pull one out which will overthrow its predecessor.
But you do not see that in reality none of these theories come from me;
they all come from him who talks with me. I only know just enough to
extract them from the wisdom of another, and to receive them in a
spirit of fairness. And now I shall say nothing myself, but shall
endeavour to elicit something from our young friend.
THEODORUS: Do as you say, Socrates;
you are quite right.
SOCRATES: Shall I tell you,
Theodorus, what amazes me in your acquaintance Protagoras?
THEODORUS: What is it?
SOCRATES: I am charmed with his
doctrine, that what appears is to each one, but I wonder that he did
not begin his book on Truth with a declaration that a pig or a
dog-faced baboon, or some other yet stranger monster which has
sensation, is the measure of all things; then he might have shown a
magnificent contempt for our opinion of him by informing us at the
outset that while we were reverencing him like a God for his wisdom he
was no better than a tadpole, not to speak of his fellow-men—would not
this have produced an overpowering effect? For if truth is only
sensation, and no man can discern another's feelings better than he, or
has any superior right to determine whether his opinion is true or
false, but each, as we have several times repeated, is to himself the
sole judge, and everything that he judges is true and right, why, my
friend, should Protagoras be preferred to the place of wisdom and
instruction, and deserve to be well paid, and we poor ignoramuses have
to go to him, if each one is the measure of his own wisdom? Must he not
be talking 'ad captandum' in all this? I say nothing of the ridiculous
predicament in which my own midwifery and the whole art of dialectic is
placed; for the attempt to supervise or refute the notions or opinions
of others would be a tedious and enormous piece of folly, if to each
man his own are right; and this must be the case if Protagoras' Truth
is the real truth, and the philosopher is not merely amusing himself by
giving oracles out of the shrine of his book.
THEODORUS: He was a friend of mine,
Socrates, as you were saying, and therefore I cannot have him refuted
by my lips, nor can I oppose you when I agree with you; please, then,
to take Theaetetus again; he seemed to answer very nicely.
SOCRATES: If you were to go into a
Lacedaemonian palestra, Theodorus, would you have a right to look on at
the naked wrestlers, some of them making a poor figure, if you did not
strip and give them an opportunity of judging of your own person?
THEODORUS: Why not, Socrates, if
they would allow me, as I think you will, in consideration of my age
and stiffness; let some more supple youth try a fall with you, and do
not drag me into the gymnasium.
SOCRATES: Your will is my will,
Theodorus, as the proverbial philosophers say, and therefore I will
return to the sage Theaetetus: Tell me, Theaetetus, in reference to
what I was saying, are you not lost in wonder, like myself, when you
find that all of a sudden you are raised to the level of the wisest of
men, or indeed of the gods?—for you would assume the measure of
Protagoras to apply to the gods as well as men?
THEAETETUS: Certainly I should, and
I confess to you that I am lost in wonder. At first hearing, I was
quite satisfied with the doctrine, that whatever appears is to each
one, but now the face of things has changed.
SOCRATES: Why, my dear boy, you are
young, and therefore your ear is quickly caught and your mind
influenced by popular arguments. Protagoras, or some one speaking on
his behalf, will doubtless say in reply,—Good people, young and old,
you meet and harangue, and bring in the gods, whose existence or
non-existence I banish from writing and speech, or you talk about the
reason of man being degraded to the level of the brutes, which is a
telling argument with the multitude, but not one word of proof or
demonstration do you offer. All is probability with you, and yet surely
you and Theodorus had better reflect whether you are disposed to admit
of probability and figures of speech in matters of such importance. He
or any other mathematician who argued from probabilities and
likelihoods in geometry, would not be worth an ace.
THEAETETUS: But neither you nor we,
Socrates, would be satisfied with such arguments.
SOCRATES: Then you and Theodorus
mean to say that we must look at the matter in some other way?
THEAETETUS: Yes, in quite another
SOCRATES: And the way will be to ask
whether perception is or is not the same as knowledge; for this was the
real point of our argument, and with a view to this we raised (did we
not?) those many strange questions.
SOCRATES: Shall we say that we know
every thing which we see and hear? for example, shall we say that not
having learned, we do not hear the language of foreigners when they
speak to us? or shall we say that we not only hear, but know what they
are saying? Or again, if we see letters which we do not understand,
shall we say that we do not see them? or shall we aver that, seeing
them, we must know them?
THEAETETUS: We shall say, Socrates,
that we know what we actually see and hear of them—that is to say, we
see and know the figure and colour of the letters, and we hear and know
the elevation or depression of the sound of them; but we do not
perceive by sight and hearing, or know, that which grammarians and
interpreters teach about them.
SOCRATES: Capital, Theaetetus; and
about this there shall be no dispute, because I want you to grow; but
there is another difficulty coming, which you will also have to
THEAETETUS: What is it?
SOCRATES: Some one will say, Can a
man who has ever known anything, and still has and preserves a memory
of that which he knows, not know that which he remembers at the time
when he remembers? I have, I fear, a tedious way of putting a simple
question, which is only, whether a man who has learned, and remembers,
can fail to know?
THEAETETUS: Impossible, Socrates;
the supposition is monstrous.
SOCRATES: Am I talking nonsense,
then? Think: is not seeing perceiving, and is not sight perception?
SOCRATES: And if our recent
definition holds, every man knows that which he has seen?
SOCRATES: And you would admit that
there is such a thing as memory?
SOCRATES: And is memory of something
or of nothing?
THEAETETUS: Of something, surely.
SOCRATES: Of things learned and
perceived, that is?
SOCRATES: Often a man remembers that
which he has seen?
SOCRATES: And if he closed his eyes,
would he forget?
THEAETETUS: Who, Socrates, would
dare to say so?
SOCRATES: But we must say so, if the
previous argument is to be maintained.
THEAETETUS: What do you mean? I am
not quite sure that I understand you, though I have a strong suspicion
that you are right.
SOCRATES: As thus: he who sees
knows, as we say, that which he sees; for perception and sight and
knowledge are admitted to be the same.
SOCRATES: But he who saw, and has
knowledge of that which he saw, remembers, when he closes his eyes,
that which he no longer sees.
SOCRATES: And seeing is knowing, and
therefore not-seeing is not-knowing?
THEAETETUS: Very true.
SOCRATES: Then the inference is,
that a man may have attained the knowledge of something, which he may
remember and yet not know, because he does not see; and this has been
affirmed by us to be a monstrous supposition.
THEAETETUS: Most true.
SOCRATES: Thus, then, the assertion
that knowledge and perception are one, involves a manifest
SOCRATES: Then they must be
THEAETETUS: I suppose that they
SOCRATES: Once more we shall have to
begin, and ask 'What is knowledge?' and yet, Theaetetus, what are we
going to do?
THEAETETUS: About what?
SOCRATES: Like a good-for-nothing
cock, without having won the victory, we walk away from the argument
THEAETETUS: How do you mean?
SOCRATES: After the manner of
disputers (Lys.; Phaedo; Republic), we were satisfied with mere verbal
consistency, and were well pleased if in this way we could gain an
advantage. Although professing not to be mere Eristics, but
philosophers, I suspect that we have unconsciously fallen into the
error of that ingenious class of persons.
THEAETETUS: I do not as yet
SOCRATES: Then I will try to explain
myself: just now we asked the question, whether a man who had learned
and remembered could fail to know, and we showed that a person who had
seen might remember when he had his eyes shut and could not see, and
then he would at the same time remember and not know. But this was an
impossibility. And so the Protagorean fable came to nought, and yours
also, who maintained that knowledge is the same as perception.
SOCRATES: And yet, my friend, I
rather suspect that the result would have been different if Protagoras,
who was the father of the first of the two brats, had been alive; he
would have had a great deal to say on their behalf. But he is dead, and
we insult over his orphan child; and even the guardians whom he left,
and of whom our friend Theodorus is one, are unwilling to give any
help, and therefore I suppose that I must take up his cause myself, and
see justice done?
THEODORUS: Not I, Socrates, but
rather Callias, the son of Hipponicus, is guardian of his orphans. I
was too soon diverted from the abstractions of dialectic to geometry.
Nevertheless, I shall be grateful to you if you assist him.
SOCRATES: Very good, Theodorus; you
shall see how I will come to the rescue. If a person does not attend to
the meaning of terms as they are commonly used in argument, he may be
involved even in greater paradoxes than these. Shall I explain this
matter to you or to Theaetetus?
THEODORUS: To both of us, and let
the younger answer; he will incur less disgrace if he is discomfited.
SOCRATES: Then now let me ask the
awful question, which is this:—Can a man know and also not know that
which he knows?
THEODORUS: How shall we answer,
THEAETETUS: He cannot, I should say.
SOCRATES: He can, if you maintain
that seeing is knowing. When you are imprisoned in a well, as the
saying is, and the self-assured adversary closes one of your eyes with
his hand, and asks whether you can see his cloak with the eye which he
has closed, how will you answer the inevitable man?
THEAETETUS: I should answer, 'Not
with that eye but with the other.'
SOCRATES: Then you see and do not
see the same thing at the same time.
THEAETETUS: Yes, in a certain sense.
SOCRATES: None of that, he will
reply; I do not ask or bid you answer in what sense you know, but only
whether you know that which you do not know. You have been proved to
see that which you do not see; and you have already admitted that
seeing is knowing, and that not-seeing is not-knowing: I leave you to
draw the inference.
THEAETETUS: Yes; the inference is
the contradictory of my assertion.
SOCRATES: Yes, my marvel, and there
might have been yet worse things in store for you, if an opponent had
gone on to ask whether you can have a sharp and also a dull knowledge,
and whether you can know near, but not at a distance, or know the same
thing with more or less intensity, and so on without end. Such
questions might have been put to you by a light-armed mercenary, who
argued for pay. He would have lain in wait for you, and when you took
up the position, that sense is knowledge, he would have made an assault
upon hearing, smelling, and the other senses;—he would have shown you
no mercy; and while you were lost in envy and admiration of his wisdom,
he would have got you into his net, out of which you would not have
escaped until you had come to an understanding about the sum to be paid
for your release. Well, you ask, and how will Protagoras reinforce his
position? Shall I answer for him?
THEAETETUS: By all means.
SOCRATES: He will repeat all those
things which we have been urging on his behalf, and then he will close
with us in disdain, and say:—The worthy Socrates asked a little boy,
whether the same man could remember and not know the same thing, and
the boy said No, because he was frightened, and could not see what was
coming, and then Socrates made fun of poor me. The truth is, O
slatternly Socrates, that when you ask questions about any assertion of
mine, and the person asked is found tripping, if he has answered as I
should have answered, then I am refuted, but if he answers something
else, then he is refuted and not I. For do you really suppose that any
one would admit the memory which a man has of an impression which has
passed away to be the same with that which he experienced at the time?
Assuredly not. Or would he hesitate to acknowledge that the same man
may know and not know the same thing? Or, if he is afraid of making
this admission, would he ever grant that one who has become unlike is
the same as before he became unlike? Or would he admit that a man is
one at all, and not rather many and infinite as the changes which take
place in him? I speak by the card in order to avoid entanglements of
words. But, O my good sir, he will say, come to the argument in a more
generous spirit; and either show, if you can, that our sensations are
not relative and individual, or, if you admit them to be so, prove that
this does not involve the consequence that the appearance becomes, or,
if you will have the word, is, to the individual only. As to your talk
about pigs and baboons, you are yourself behaving like a pig, and you
teach your hearers to make sport of my writings in the same ignorant
manner; but this is not to your credit. For I declare that the truth is
as I have written, and that each of us is a measure of existence and of
non-existence. Yet one man may be a thousand times better than another
in proportion as different things are and appear to him. And I am far
from saying that wisdom and the wise man have no existence; but I say
that the wise man is he who makes the evils which appear and are to a
man, into goods which are and appear to him. And I would beg you not to
press my words in the letter, but to take the meaning of them as I will
explain them. Remember what has been already said,—that to the sick man
his food appears to be and is bitter, and to the man in health the
opposite of bitter. Now I cannot conceive that one of these men can be
or ought to be made wiser than the other: nor can you assert that the
sick man because he has one impression is foolish, and the healthy man
because he has another is wise; but the one state requires to be
changed into the other, the worse into the better. As in education, a
change of state has to be effected, and the sophist accomplishes by
words the change which the physician works by the aid of drugs. Not
that any one ever made another think truly, who previously thought
falsely. For no one can think what is not, or, think anything different
from that which he feels; and this is always true. But as the inferior
habit of mind has thoughts of kindred nature, so I conceive that a good
mind causes men to have good thoughts; and these which the
inexperienced call true, I maintain to be only better, and not truer
than others. And, O my dear Socrates, I do not call wise men tadpoles:
far from it; I say that they are the physicians of the human body, and
the husbandmen of plants—for the husbandmen also take away the evil and
disordered sensations of plants, and infuse into them good and healthy
sensations—aye and true ones; and the wise and good rhetoricians make
the good instead of the evil to seem just to states; for whatever
appears to a state to be just and fair, so long as it is regarded as
such, is just and fair to it; but the teacher of wisdom causes the good
to take the place of the evil, both in appearance and in reality. And
in like manner the Sophist who is able to train his pupils in this
spirit is a wise man, and deserves to be well paid by them. And so one
man is wiser than another; and no one thinks falsely, and you, whether
you will or not, must endure to be a measure. On these foundations the
argument stands firm, which you, Socrates, may, if you please,
overthrow by an opposite argument, or if you like you may put questions
to me—a method to which no intelligent person will object, quite the
reverse. But I must beg you to put fair questions: for there is great
inconsistency in saying that you have a zeal for virtue, and then
always behaving unfairly in argument. The unfairness of which I
complain is that you do not distinguish between mere disputation and
dialectic: the disputer may trip up his opponent as often as he likes,
and make fun; but the dialectician will be in earnest, and only correct
his adversary when necessary, telling him the errors into which he has
fallen through his own fault, or that of the company which he has
previously kept. If you do so, your adversary will lay the blame of his
own confusion and perplexity on himself, and not on you. He will follow
and love you, and will hate himself, and escape from himself into
philosophy, in order that he may become different from what he was. But
the other mode of arguing, which is practised by the many, will have
just the opposite effect upon him; and as he grows older, instead of
turning philosopher, he will come to hate philosophy. I would recommend
you, therefore, as I said before, not to encourage yourself in this
polemical and controversial temper, but to find out, in a friendly and
congenial spirit, what we really mean when we say that all things are
in motion, and that to every individual and state what appears, is. In
this manner you will consider whether knowledge and sensation are the
same or different, but you will not argue, as you were just now doing,
from the customary use of names and words, which the vulgar pervert in
all sorts of ways, causing infinite perplexity to one another. Such,
Theodorus, is the very slight help which I am able to offer to your old
friend; had he been living, he would have helped himself in a far more
THEODORUS: You are jesting,
Socrates; indeed, your defence of him has been most valorous.
SOCRATES: Thank you, friend; and I
hope that you observed Protagoras bidding us be serious, as the text,
'Man is the measure of all things,' was a solemn one; and he reproached
us with making a boy the medium of discourse, and said that the boy's
timidity was made to tell against his argument; he also declared that
we made a joke of him.
THEODORUS: How could I fail to
observe all that, Socrates?
SOCRATES: Well, and shall we do as
THEODORUS: By all means.
SOCRATES: But if his wishes are to
be regarded, you and I must take up the argument, and in all
seriousness, and ask and answer one another, for you see that the rest
of us are nothing but boys. In no other way can we escape the
imputation, that in our fresh analysis of his thesis we are making fun
THEODORUS: Well, but is not
Theaetetus better able to follow a philosophical enquiry than a great
many men who have long beards?
SOCRATES: Yes, Theodorus, but not
better than you; and therefore please not to imagine that I am to
defend by every means in my power your departed friend; and that you
are to defend nothing and nobody. At any rate, my good man, do not
sheer off until we know whether you are a true measure of diagrams, or
whether all men are equally measures and sufficient for themselves in
astronomy and geometry, and the other branches of knowledge in which
you are supposed to excel them.
THEODORUS: He who is sitting by you,
Socrates, will not easily avoid being drawn into an argument; and when
I said just now that you would excuse me, and not, like the
Lacedaemonians, compel me to strip and fight, I was talking nonsense—I
should rather compare you to Scirrhon, who threw travellers from the
rocks; for the Lacedaemonian rule is 'strip or depart,' but you seem to
go about your work more after the fashion of Antaeus: you will not
allow any one who approaches you to depart until you have stripped him,
and he has been compelled to try a fall with you in argument.
SOCRATES: There, Theodorus, you have
hit off precisely the nature of my complaint; but I am even more
pugnacious than the giants of old, for I have met with no end of
heroes; many a Heracles, many a Theseus, mighty in words, has broken my
head; nevertheless I am always at this rough exercise, which inspires
me like a passion. Please, then, to try a fall with me, whereby you
will do yourself good as well as me.
THEODORUS: I consent; lead me
whither you will, for I know that you are like destiny; no man can
escape from any argument which you may weave for him. But I am not
disposed to go further than you suggest.
SOCRATES: Once will be enough; and
now take particular care that we do not again unwittingly expose
ourselves to the reproach of talking childishly.
THEODORUS: I will do my best to
avoid that error.
SOCRATES: In the first place, let us
return to our old objection, and see whether we were right in blaming
and taking offence at Protagoras on the ground that he assumed all to
be equal and sufficient in wisdom; although he admitted that there was
a better and worse, and that in respect of this, some who as he said
were the wise excelled others.
THEODORUS: Very true.
SOCRATES: Had Protagoras been living
and answered for himself, instead of our answering for him, there would
have been no need of our reviewing or reinforcing the argument. But as
he is not here, and some one may accuse us of speaking without
authority on his behalf, had we not better come to a clearer agreement
about his meaning, for a great deal may be at stake?
SOCRATES: Then let us obtain, not
through any third person, but from his own statement and in the fewest
words possible, the basis of agreement.
THEODORUS: In what way?
SOCRATES: In this way:—His words
are, 'What seems to a man, is to him.'
THEODORUS: Yes, so he says.
SOCRATES: And are not we,
Protagoras, uttering the opinion of man, or rather of all mankind, when
we say that every one thinks himself wiser than other men in some
things, and their inferior in others? In the hour of danger, when they
are in perils of war, or of the sea, or of sickness, do they not look
up to their commanders as if they were gods, and expect salvation from
them, only because they excel them in knowledge? Is not the world full
of men in their several employments, who are looking for teachers and
rulers of themselves and of the animals? and there are plenty who think
that they are able to teach and able to rule. Now, in all this is
implied that ignorance and wisdom exist among them, at least in their
SOCRATES: And wisdom is assumed by
them to be true thought, and ignorance to be false opinion.
SOCRATES: How then, Protagoras,
would you have us treat the argument? Shall we say that the opinions of
men are always true, or sometimes true and sometimes false? In either
case, the result is the same, and their opinions are not always true,
but sometimes true and sometimes false. For tell me, Theodorus, do you
suppose that you yourself, or any other follower of Protagoras, would
contend that no one deems another ignorant or mistaken in his opinion?
THEODORUS: The thing is incredible,
SOCRATES: And yet that absurdity is
necessarily involved in the thesis which declares man to be the measure
of all things.
THEODORUS: How so?
SOCRATES: Why, suppose that you
determine in your own mind something to be true, and declare your
opinion to me; let us assume, as he argues, that this is true to you.
Now, if so, you must either say that the rest of us are not the judges
of this opinion or judgment of yours, or that we judge you always to
have a true opinion? But are there not thousands upon thousands who,
whenever you form a judgment, take up arms against you and are of an
opposite judgment and opinion, deeming that you judge falsely?
THEODORUS: Yes, indeed, Socrates,
thousands and tens of thousands, as Homer says, who give me a world of
SOCRATES: Well, but are we to assert
that what you think is true to you and false to the ten thousand
THEODORUS: No other inference seems
to be possible.
SOCRATES: And how about Protagoras
himself? If neither he nor the multitude thought, as indeed they do not
think, that man is the measure of all things, must it not follow that
the truth of which Protagoras wrote would be true to no one? But if you
suppose that he himself thought this, and that the multitude does not
agree with him, you must begin by allowing that in whatever proportion
the many are more than one, in that proportion his truth is more untrue
THEODORUS: That would follow if the
truth is supposed to vary with individual opinion.
SOCRATES: And the best of the joke
is, that he acknowledges the truth of their opinion who believe his own
opinion to be false; for he admits that the opinions of all men are
SOCRATES: And does he not allow that
his own opinion is false, if he admits that the opinion of those who
think him false is true?
THEODORUS: Of course.
SOCRATES: Whereas the other side do
not admit that they speak falsely?
THEODORUS: They do not.
SOCRATES: And he, as may be inferred
from his writings, agrees that this opinion is also true.
SOCRATES: Then all mankind,
beginning with Protagoras, will contend, or rather, I should say that
he will allow, when he concedes that his adversary has a true
opinion—Protagoras, I say, will himself allow that neither a dog nor
any ordinary man is the measure of anything which he has not learned—am
I not right?
SOCRATES: And the truth of
Protagoras being doubted by all, will be true neither to himself to any
THEODORUS: I think, Socrates, that
we are running my old friend too hard.
SOCRATES: But I do not know that we
are going beyond the truth. Doubtless, as he is older, he may be
expected to be wiser than we are. And if he could only just get his
head out of the world below, he would have overthrown both of us again
and again, me for talking nonsense and you for assenting to me, and
have been off and underground in a trice. But as he is not within call,
we must make the best use of our own faculties, such as they are, and
speak out what appears to us to be true. And one thing which no one
will deny is, that there are great differences in the understandings of
THEODORUS: In that opinion I quite
SOCRATES: And is there not most
likely to be firm ground in the distinction which we were indicating on
behalf of Protagoras, viz. that most things, and all immediate
sensations, such as hot, dry, sweet, are only such as they appear; if
however difference of opinion is to be allowed at all, surely we must
allow it in respect of health or disease? for every woman, child, or
living creature has not such a knowledge of what conduces to health as
to enable them to cure themselves.
THEODORUS: I quite agree.
SOCRATES: Or again, in politics,
while affirming that just and unjust, honourable and disgraceful, holy
and unholy, are in reality to each state such as the state thinks and
makes lawful, and that in determining these matters no individual or
state is wiser than another, still the followers of Protagoras will not
deny that in determining what is or is not expedient for the community
one state is wiser and one counsellor better than another—they will
scarcely venture to maintain, that what a city enacts in the belief
that it is expedient will always be really expedient. But in the other
case, I mean when they speak of justice and injustice, piety and
impiety, they are confident that in nature these have no existence or
essence of their own—the truth is that which is agreed on at the time
of the agreement, and as long as the agreement lasts; and this is the
philosophy of many who do not altogether go along with Protagoras. Here
arises a new question, Theodorus, which threatens to be more serious
than the last.
THEODORUS: Well, Socrates, we have
plenty of leisure.
SOCRATES: That is true, and your
remark recalls to my mind an observation which I have often made, that
those who have passed their days in the pursuit of philosophy are
ridiculously at fault when they have to appear and speak in court. How
natural is this!
THEODORUS: What do you mean?
SOCRATES: I mean to say, that those
who have been trained in philosophy and liberal pursuits are as unlike
those who from their youth upwards have been knocking about in the
courts and such places, as a freeman is in breeding unlike a slave.
THEODORUS: In what is the difference
SOCRATES: In the leisure spoken of
by you, which a freeman can always command: he has his talk out in
peace, and, like ourselves, he wanders at will from one subject to
another, and from a second to a third,—if the fancy takes him, he
begins again, as we are doing now, caring not whether his words are
many or few; his only aim is to attain the truth. But the lawyer is
always in a hurry; there is the water of the clepsydra driving him on,
and not allowing him to expatiate at will: and there is his adversary
standing over him, enforcing his rights; the indictment, which in their
phraseology is termed the affidavit, is recited at the time: and from
this he must not deviate. He is a servant, and is continually disputing
about a fellow-servant before his master, who is seated, and has the
cause in his hands; the trial is never about some indifferent matter,
but always concerns himself; and often the race is for his life. The
consequence has been, that he has become keen and shrewd; he has
learned how to flatter his master in word and indulge him in deed; but
his soul is small and unrighteous. His condition, which has been that
of a slave from his youth upwards, has deprived him of growth and
uprightness and independence; dangers and fears, which were too much
for his truth and honesty, came upon him in early years, when the
tenderness of youth was unequal to them, and he has been driven into
crooked ways; from the first he has practised deception and
retaliation, and has become stunted and warped. And so he has passed
out of youth into manhood, having no soundness in him; and is now, as
he thinks, a master in wisdom. Such is the lawyer, Theodorus. Will you
have the companion picture of the philosopher, who is of our
brotherhood; or shall we return to the argument? Do not let us abuse
the freedom of digression which we claim.
THEODORUS: Nay, Socrates, not until
we have finished what we are about; for you truly said that we belong
to a brotherhood which is free, and are not the servants of the
argument; but the argument is our servant, and must wait our leisure.
Who is our judge? Or where is the spectator having any right to censure
or control us, as he might the poets?
SOCRATES: Then, as this is your
wish, I will describe the leaders; for there is no use in talking about
the inferior sort. In the first place, the lords of philosophy have
never, from their youth upwards, known their way to the Agora, or the
dicastery, or the council, or any other political assembly; they
neither see nor hear the laws or decrees, as they are called, of the
state written or recited; the eagerness of political societies in the
attainment of offices—clubs, and banquets, and revels, and
singing-maidens,—do not enter even into their dreams. Whether any event
has turned out well or ill in the city, what disgrace may have
descended to any one from his ancestors, male or female, are matters of
which the philosopher no more knows than he can tell, as they say, how
many pints are contained in the ocean. Neither is he conscious of his
ignorance. For he does not hold aloof in order that he may gain a
reputation; but the truth is, that the outer form of him only is in the
city: his mind, disdaining the littlenesses and nothingnesses of human
things, is 'flying all abroad' as Pindar says, measuring earth and
heaven and the things which are under and on the earth and above the
heaven, interrogating the whole nature of each and all in their
entirety, but not condescending to anything which is within reach.
THEODORUS: What do you mean,
SOCRATES: I will illustrate my
meaning, Theodorus, by the jest which the clever witty Thracian
handmaid is said to have made about Thales, when he fell into a well as
he was looking up at the stars. She said, that he was so eager to know
what was going on in heaven, that he could not see what was before his
feet. This is a jest which is equally applicable to all philosophers.
For the philosopher is wholly unacquainted with his next-door
neighbour; he is ignorant, not only of what he is doing, but he hardly
knows whether he is a man or an animal; he is searching into the
essence of man, and busy in enquiring what belongs to such a nature to
do or suffer different from any other;—I think that you understand me,
THEODORUS: I do, and what you say is
SOCRATES: And thus, my friend, on
every occasion, private as well as public, as I said at first, when he
appears in a law-court, or in any place in which he has to speak of
things which are at his feet and before his eyes, he is the jest, not
only of Thracian handmaids but of the general herd, tumbling into wells
and every sort of disaster through his inexperience. His awkwardness is
fearful, and gives the impression of imbecility. When he is reviled, he
has nothing personal to say in answer to the civilities of his
adversaries, for he knows no scandals of any one, and they do not
interest him; and therefore he is laughed at for his sheepishness; and
when others are being praised and glorified, in the simplicity of his
heart he cannot help going into fits of laughter, so that he seems to
be a downright idiot. When he hears a tyrant or king eulogized, he
fancies that he is listening to the praises of some keeper of cattle—a
swineherd, or shepherd, or perhaps a cowherd, who is congratulated on
the quantity of milk which he squeezes from them; and he remarks that
the creature whom they tend, and out of whom they squeeze the wealth,
is of a less tractable and more insidious nature. Then, again, he
observes that the great man is of necessity as ill-mannered and
uneducated as any shepherd—for he has no leisure, and he is surrounded
by a wall, which is his mountain-pen. Hearing of enormous landed
proprietors of ten thousand acres and more, our philosopher deems this
to be a trifle, because he has been accustomed to think of the whole
earth; and when they sing the praises of family, and say that some one
is a gentleman because he can show seven generations of wealthy
ancestors, he thinks that their sentiments only betray a dull and
narrow vision in those who utter them, and who are not educated enough
to look at the whole, nor to consider that every man has had thousands
and ten thousands of progenitors, and among them have been rich and
poor, kings and slaves, Hellenes and barbarians, innumerable. And when
people pride themselves on having a pedigree of twenty-five ancestors,
which goes back to Heracles, the son of Amphitryon, he cannot
understand their poverty of ideas. Why are they unable to calculate
that Amphitryon had a twenty-fifth ancestor, who might have been
anybody, and was such as fortune made him, and he had a fiftieth, and
so on? He amuses himself with the notion that they cannot count, and
thinks that a little arithmetic would have got rid of their senseless
vanity. Now, in all these cases our philosopher is derided by the
vulgar, partly because he is thought to despise them, and also because
he is ignorant of what is before him, and always at a loss.
THEODORUS: That is very true,
SOCRATES: But, O my friend, when he
draws the other into upper air, and gets him out of his pleas and
rejoinders into the contemplation of justice and injustice in their own
nature and in their difference from one another and from all other
things; or from the commonplaces about the happiness of a king or of a
rich man to the consideration of government, and of human happiness and
misery in general—what they are, and how a man is to attain the one and
avoid the other—when that narrow, keen, little legal mind is called to
account about all this, he gives the philosopher his revenge; for
dizzied by the height at which he is hanging, whence he looks down into
space, which is a strange experience to him, he being dismayed, and
lost, and stammering broken words, is laughed at, not by Thracian
handmaidens or any other uneducated persons, for they have no eye for
the situation, but by every man who has not been brought up a slave.
Such are the two characters, Theodorus: the one of the freeman, who has
been trained in liberty and leisure, whom you call the philosopher,—him
we cannot blame because he appears simple and of no account when he has
to perform some menial task, such as packing up bed-clothes, or
flavouring a sauce or fawning speech; the other character is that of
the man who is able to do all this kind of service smartly and neatly,
but knows not how to wear his cloak like a gentleman; still less with
the music of discourse can he hymn the true life aright which is lived
by immortals or men blessed of heaven.
THEODORUS: If you could only
persuade everybody, Socrates, as you do me, of the truth of your words,
there would be more peace and fewer evils among men.
SOCRATES: Evils, Theodorus, can
never pass away; for there must always remain something which is
antagonistic to good. Having no place among the gods in heaven, of
necessity they hover around the mortal nature, and this earthly sphere.
Wherefore we ought to fly away from earth to heaven as quickly as we
can; and to fly away is to become like God, as far as this is possible;
and to become like him, is to become holy, just, and wise. But, O my
friend, you cannot easily convince mankind that they should pursue
virtue or avoid vice, not merely in order that a man may seem to be
good, which is the reason given by the world, and in my judgment is
only a repetition of an old wives' fable. Whereas, the truth is that
God is never in any way unrighteous—he is perfect righteousness; and he
of us who is the most righteous is most like him. Herein is seen the
true cleverness of a man, and also his nothingness and want of manhood.
For to know this is true wisdom and virtue, and ignorance of this is
manifest folly and vice. All other kinds of wisdom or cleverness, which
seem only, such as the wisdom of politicians, or the wisdom of the
arts, are coarse and vulgar. The unrighteous man, or the sayer and doer
of unholy things, had far better not be encouraged in the illusion that
his roguery is clever; for men glory in their shame—they fancy that
they hear others saying of them, 'These are not mere good-for-nothing
persons, mere burdens of the earth, but such as men should be who mean
to dwell safely in a state.' Let us tell them that they are all the
more truly what they do not think they are because they do not know it;
for they do not know the penalty of injustice, which above all things
they ought to know—not stripes and death, as they suppose, which
evil-doers often escape, but a penalty which cannot be escaped.
THEODORUS: What is that?
SOCRATES: There are two patterns
eternally set before them; the one blessed and divine, the other
godless and wretched: but they do not see them, or perceive that in
their utter folly and infatuation they are growing like the one and
unlike the other, by reason of their evil deeds; and the penalty is,
that they lead a life answering to the pattern which they are growing
like. And if we tell them, that unless they depart from their cunning,
the place of innocence will not receive them after death; and that here
on earth, they will live ever in the likeness of their own evil selves,
and with evil friends—when they hear this they in their superior
cunning will seem to be listening to the talk of idiots.
THEODORUS: Very true, Socrates.
SOCRATES: Too true, my friend, as I
well know; there is, however, one peculiarity in their case: when they
begin to reason in private about their dislike of philosophy, if they
have the courage to hear the argument out, and do not run away, they
grow at last strangely discontented with themselves; their rhetoric
fades away, and they become helpless as children. These however are
digressions from which we must now desist, or they will overflow, and
drown the original argument; to which, if you please, we will now
THEODORUS: For my part, Socrates, I
would rather have the digressions, for at my age I find them easier to
follow; but if you wish, let us go back to the argument.
SOCRATES: Had we not reached the
point at which the partisans of the perpetual flux, who say that things
are as they seem to each one, were confidently maintaining that the
ordinances which the state commanded and thought just, were just to the
state which imposed them, while they were in force; this was especially
asserted of justice; but as to the good, no one had any longer the
hardihood to contend of any ordinances which the state thought and
enacted to be good that these, while they were in force, were really
good;—he who said so would be playing with the name 'good,' and would
not touch the real question—it would be a mockery, would it not?
THEODORUS: Certainly it would.
SOCRATES: He ought not to speak of
the name, but of the thing which is contemplated under the name.
SOCRATES: Whatever be the term used,
the good or expedient is the aim of legislation, and as far as she has
an opinion, the state imposes all laws with a view to the greatest
expediency; can legislation have any other aim?
THEODORUS: Certainly not.
SOCRATES: But is the aim attained
always? do not mistakes often happen?
THEODORUS: Yes, I think that there
SOCRATES: The possibility of error
will be more distinctly recognised, if we put the question in reference
to the whole class under which the good or expedient falls. That whole
class has to do with the future, and laws are passed under the idea
that they will be useful in after-time; which, in other words, is the
THEODORUS: Very true.
SOCRATES: Suppose now, that we ask
Protagoras, or one of his disciples, a question:—O, Protagoras, we will
say to him, Man is, as you declare, the measure of all things—white,
heavy, light: of all such things he is the judge; for he has the
criterion of them in himself, and when he thinks that things are such
as he experiences them to be, he thinks what is and is true to himself.
Is it not so?
SOCRATES: And do you extend your
doctrine, Protagoras (as we shall further say), to the future as well
as to the present; and has he the criterion not only of what in his
opinion is but of what will be, and do things always happen to him as
he expected? For example, take the case of heat:—When an ordinary man
thinks that he is going to have a fever, and that this kind of heat is
coming on, and another person, who is a physician, thinks the contrary,
whose opinion is likely to prove right? Or are they both right?—he will
have a heat and fever in his own judgment, and not have a fever in the
THEODORUS: How ludicrous!
SOCRATES: And the vinegrower, if I
am not mistaken, is a better judge of the sweetness or dryness of the
vintage which is not yet gathered than the harp-player?
SOCRATES: And in musical composition
the musician will know better than the training master what the
training master himself will hereafter think harmonious or the reverse?
THEODORUS: Of course.
SOCRATES: And the cook will be a
better judge than the guest, who is not a cook, of the pleasure to be
derived from the dinner which is in preparation; for of present or past
pleasure we are not as yet arguing; but can we say that every one will
be to himself the best judge of the pleasure which will seem to be and
will be to him in the future?—nay, would not you, Protagoras, better
guess which arguments in a court would convince any one of us than the
THEODORUS: Certainly, Socrates, he
used to profess in the strongest manner that he was the superior of all
men in this respect.
SOCRATES: To be sure, friend: who
would have paid a large sum for the privilege of talking to him, if he
had really persuaded his visitors that neither a prophet nor any other
man was better able to judge what will be and seem to be in the future
than every one could for himself?
THEODORUS: Who indeed?
SOCRATES: And legislation and
expediency are all concerned with the future; and every one will admit
that states, in passing laws, must often fail of their highest
THEODORUS: Quite true.
SOCRATES: Then we may fairly argue
against your master, that he must admit one man to be wiser than
another, and that the wiser is a measure: but I, who know nothing, am
not at all obliged to accept the honour which the advocate of
Protagoras was just now forcing upon me, whether I would or not, of
being a measure of anything.
THEODORUS: That is the best
refutation of him, Socrates; although he is also caught when he
ascribes truth to the opinions of others, who give the lie direct to
his own opinion.
SOCRATES: There are many ways,
Theodorus, in which the doctrine that every opinion of every man is
true may be refuted; but there is more difficulty in proving that
states of feeling, which are present to a man, and out of which arise
sensations and opinions in accordance with them, are also untrue. And
very likely I have been talking nonsense about them; for they may be
unassailable, and those who say that there is clear evidence of them,
and that they are matters of knowledge, may probably be right; in which
case our friend Theaetetus was not so far from the mark when he
identified perception and knowledge. And therefore let us draw nearer,
as the advocate of Protagoras desires; and give the truth of the
universal flux a ring: is the theory sound or not? at any rate, no
small war is raging about it, and there are combination not a few.
THEODORUS: No small, war, indeed,
for in Ionia the sect makes rapid strides; the disciples of Heracleitus
are most energetic upholders of the doctrine.
SOCRATES: Then we are the more
bound, my dear Theodorus, to examine the question from the foundation
as it is set forth by themselves.
THEODORUS: Certainly we are. About
these speculations of Heracleitus, which, as you say, are as old as
Homer, or even older still, the Ephesians themselves, who profess to
know them, are downright mad, and you cannot talk with them on the
subject. For, in accordance with their text-books, they are always in
motion; but as for dwelling upon an argument or a question, and quietly
asking and answering in turn, they can no more do so than they can fly;
or rather, the determination of these fellows not to have a particle of
rest in them is more than the utmost powers of negation can express. If
you ask any of them a question, he will produce, as from a quiver,
sayings brief and dark, and shoot them at you; and if you inquire the
reason of what he has said, you will be hit by some other new-fangled
word, and will make no way with any of them, nor they with one another;
their great care is, not to allow of any settled principle either in
their arguments or in their minds, conceiving, as I imagine, that any
such principle would be stationary; for they are at war with the
stationary, and do what they can to drive it out everywhere.
SOCRATES: I suppose, Theodorus, that
you have only seen them when they were fighting, and have never stayed
with them in time of peace, for they are no friends of yours; and their
peace doctrines are only communicated by them at leisure, as I imagine,
to those disciples of theirs whom they want to make like themselves.
THEODORUS: Disciples! my good sir,
they have none; men of their sort are not one another's disciples, but
they grow up at their own sweet will, and get their inspiration
anywhere, each of them saying of his neighbour that he knows nothing.
From these men, then, as I was going to remark, you will never get a
reason, whether with their will or without their will; we must take the
question out of their hands, and make the analysis ourselves, as if we
were doing geometrical problem.
SOCRATES: Quite right too; but as
touching the aforesaid problem, have we not heard from the ancients,
who concealed their wisdom from the many in poetical figures, that
Oceanus and Tethys, the origin of all things, are streams, and that
nothing is at rest? And now the moderns, in their superior wisdom, have
declared the same openly, that the cobbler too may hear and learn of
them, and no longer foolishly imagine that some things are at rest and
others in motion—having learned that all is motion, he will duly honour
his teachers. I had almost forgotten the opposite doctrine, Theodorus,
'Alone Being remains unmoved, which is the name for the all.'
This is the language of Parmenides,
Melissus, and their followers, who stoutly maintain that all being is
one and self-contained, and has no place in which to move. What shall
we do, friend, with all these people; for, advancing step by step, we
have imperceptibly got between the combatants, and, unless we can
protect our retreat, we shall pay the penalty of our rashness—like the
players in the palaestra who are caught upon the line, and are dragged
different ways by the two parties. Therefore I think that we had better
begin by considering those whom we first accosted, 'the river-gods,'
and, if we find any truth in them, we will help them to pull us over,
and try to get away from the others. But if the partisans of 'the
whole' appear to speak more truly, we will fly off from the party which
would move the immovable, to them. And if I find that neither of them
have anything reasonable to say, we shall be in a ridiculous position,
having so great a conceit of our own poor opinion and rejecting that of
ancient and famous men. O Theodorus, do you think that there is any use
in proceeding when the danger is so great?
THEODORUS: Nay, Socrates, not to
examine thoroughly what the two parties have to say would be quite
SOCRATES: Then examine we must,
since you, who were so reluctant to begin, are so eager to proceed. The
nature of motion appears to be the question with which we begin. What
do they mean when they say that all things are in motion? Is there only
one kind of motion, or, as I rather incline to think, two? I should
like to have your opinion upon this point in addition to my own, that I
may err, if I must err, in your company; tell me, then, when a thing
changes from one place to another, or goes round in the same place, is
not that what is called motion?
SOCRATES: Here then we have one kind
of motion. But when a thing, remaining on the same spot, grows old, or
becomes black from being white, or hard from being soft, or undergoes
any other change, may not this be properly called motion of another
THEODORUS: I think so.
SOCRATES: Say rather that it must be
so. Of motion then there are these two kinds, 'change,' and 'motion in
THEODORUS: You are right.
SOCRATES: And now, having made this
distinction, let us address ourselves to those who say that all is
motion, and ask them whether all things according to them have the two
kinds of motion, and are changed as well as move in place, or is one
thing moved in both ways, and another in one only?
THEODORUS: Indeed, I do not know
what to answer; but I think they would say that all things are moved in
SOCRATES: Yes, comrade; for, if not,
they would have to say that the same things are in motion and at rest,
and there would be no more truth in saying that all things are in
motion, than that all things are at rest.
THEODORUS: To be sure.
SOCRATES: And if they are to be in
motion, and nothing is to be devoid of motion, all things must always
have every sort of motion?
THEODORUS: Most true.
SOCRATES: Consider a further point:
did we not understand them to explain the generation of heat,
whiteness, or anything else, in some such manner as the following:—were
they not saying that each of them is moving between the agent and the
patient, together with a perception, and that the patient ceases to be
a perceiving power and becomes a percipient, and the agent a quale
instead of a quality? I suspect that quality may appear a strange and
uncouth term to you, and that you do not understand the abstract
expression. Then I will take concrete instances: I mean to say that the
producing power or agent becomes neither heat nor whiteness but hot and
white, and the like of other things. For I must repeat what I said
before, that neither the agent nor patient have any absolute existence,
but when they come together and generate sensations and their objects,
the one becomes a thing of a certain quality, and the other a
percipient. You remember?
THEODORUS: Of course.
SOCRATES: We may leave the details
of their theory unexamined, but we must not forget to ask them the only
question with which we are concerned: Are all things in motion and
THEODORUS: Yes, they will reply.
SOCRATES: And they are moved in both
those ways which we distinguished, that is to say, they move in place
and are also changed?
THEODORUS: Of course, if the motion
is to be perfect.
SOCRATES: If they only moved in
place and were not changed, we should be able to say what is the nature
of the things which are in motion and flux?
SOCRATES: But now, since not even
white continues to flow white, and whiteness itself is a flux or change
which is passing into another colour, and is never to be caught
standing still, can the name of any colour be rightly used at all?
THEODORUS: How is that possible,
Socrates, either in the case of this or of any other quality—if while
we are using the word the object is escaping in the flux?
SOCRATES: And what would you say of
perceptions, such as sight and hearing, or any other kind of
perception? Is there any stopping in the act of seeing and hearing?
THEODORUS: Certainly not, if all
things are in motion.
SOCRATES: Then we must not speak of
seeing any more than of not-seeing, nor of any other perception more
than of any non-perception, if all things partake of every kind of
THEODORUS: Certainly not.
SOCRATES: Yet perception is
knowledge: so at least Theaetetus and I were saying.
THEODORUS: Very true.
SOCRATES: Then when we were asked
what is knowledge, we no more answered what is knowledge than what is
THEODORUS: I suppose not.
SOCRATES: Here, then, is a fine
result: we corrected our first answer in our eagerness to prove that
nothing is at rest. But if nothing is at rest, every answer upon
whatever subject is equally right: you may say that a thing is or is
not thus; or, if you prefer, 'becomes' thus; and if we say 'becomes,'
we shall not then hamper them with words expressive of rest.
THEODORUS: Quite true.
SOCRATES: Yes, Theodorus, except in
saying 'thus' and 'not thus.' But you ought not to use the word 'thus,'
for there is no motion in 'thus' or in 'not thus.' The maintainers of
the doctrine have as yet no words in which to express themselves, and
must get a new language. I know of no word that will suit them, except
perhaps 'no how,' which is perfectly indefinite.
THEODORUS: Yes, that is a manner of
speaking in which they will be quite at home.
SOCRATES: And so, Theodorus, we have
got rid of your friend without assenting to his doctrine, that every
man is the measure of all things—a wise man only is a measure; neither
can we allow that knowledge is perception, certainly not on the
hypothesis of a perpetual flux, unless perchance our friend Theaetetus
is able to convince us that it is.
THEODORUS: Very good, Socrates; and
now that the argument about the doctrine of Protagoras has been
completed, I am absolved from answering; for this was the agreement.
THEAETETUS: Not, Theodorus, until
you and Socrates have discussed the doctrine of those who say that all
things are at rest, as you were proposing.
THEODORUS: You, Theaetetus, who are
a young rogue, must not instigate your elders to a breach of faith, but
should prepare to answer Socrates in the remainder of the argument.
THEAETETUS: Yes, if he wishes; but I
would rather have heard about the doctrine of rest.
THEODORUS: Invite Socrates to an
argument—invite horsemen to the open plain; do but ask him, and he will
SOCRATES: Nevertheless, Theodorus, I
am afraid that I shall not be able to comply with the request of
THEODORUS: Not comply! for what
SOCRATES: My reason is that I have a
kind of reverence; not so much for Melissus and the others, who say
that 'All is one and at rest,' as for the great leader himself,
Parmenides, venerable and awful, as in Homeric language he may be
called;—him I should be ashamed to approach in a spirit unworthy of
him. I met him when he was an old man, and I was a mere youth, and he
appeared to me to have a glorious depth of mind. And I am afraid that
we may not understand his words, and may be still further from
understanding his meaning; above all I fear that the nature of
knowledge, which is the main subject of our discussion, may be thrust
out of sight by the unbidden guests who will come pouring in upon our
feast of discourse, if we let them in—besides, the question which is
now stirring is of immense extent, and will be treated unfairly if only
considered by the way; or if treated adequately and at length, will put
into the shade the other question of knowledge. Neither the one nor the
other can be allowed; but I must try by my art of midwifery to deliver
Theaetetus of his conceptions about knowledge.
THEAETETUS: Very well; do so if you
SOCRATES: Then now, Theaetetus, take
another view of the subject: you answered that knowledge is perception?
THEAETETUS: I did.
SOCRATES: And if any one were to ask
you: With what does a man see black and white colours? and with what
does he hear high and low sounds?—you would say, if I am not mistaken,
'With the eyes and with the ears.'
THEAETETUS: I should.
SOCRATES: The free use of words and
phrases, rather than minute precision, is generally characteristic of a
liberal education, and the opposite is pedantic; but sometimes
precision is necessary, and I believe that the answer which you have
just given is open to the charge of incorrectness; for which is more
correct, to say that we see or hear with the eyes and with the ears, or
through the eyes and through the ears.
THEAETETUS: I should say 'through,'
Socrates, rather than 'with.'
SOCRATES: Yes, my boy, for no one
can suppose that in each of us, as in a sort of Trojan horse, there are
perched a number of unconnected senses, which do not all meet in some
one nature, the mind, or whatever we please to call it, of which they
are the instruments, and with which through them we perceive objects of
THEAETETUS: I agree with you in that
SOCRATES: The reason why I am thus
precise is, because I want to know whether, when we perceive black and
white through the eyes, and again, other qualities through other
organs, we do not perceive them with one and the same part of
ourselves, and, if you were asked, you might refer all such perceptions
to the body. Perhaps, however, I had better allow you to answer for
yourself and not interfere. Tell me, then, are not the organs through
which you perceive warm and hard and light and sweet, organs of the
THEAETETUS: Of the body, certainly.
SOCRATES: And you would admit that
what you perceive through one faculty you cannot perceive through
another; the objects of hearing, for example, cannot be perceived
through sight, or the objects of sight through hearing?
THEAETETUS: Of course not.
SOCRATES: If you have any thought
about both of them, this common perception cannot come to you, either
through the one or the other organ?
THEAETETUS: It cannot.
SOCRATES: How about sounds and
colours: in the first place you would admit that they both exist?
SOCRATES: And that either of them is
different from the other, and the same with itself?
SOCRATES: And that both are two and
each of them one?
SOCRATES: You can further observe
whether they are like or unlike one another?
THEAETETUS: I dare say.
SOCRATES: But through what do you
perceive all this about them? for neither through hearing nor yet
through seeing can you apprehend that which they have in common. Let me
give you an illustration of the point at issue:—If there were any
meaning in asking whether sounds and colours are saline or not, you
would be able to tell me what faculty would consider the question. It
would not be sight or hearing, but some other.
THEAETETUS: Certainly; the faculty
SOCRATES: Very good; and now tell me
what is the power which discerns, not only in sensible objects, but in
all things, universal notions, such as those which are called being and
not-being, and those others about which we were just asking—what organs
will you assign for the perception of these notions?
THEAETETUS: You are thinking of
being and not being, likeness and unlikeness, sameness and difference,
and also of unity and other numbers which are applied to objects of
sense; and you mean to ask, through what bodily organ the soul
perceives odd and even numbers and other arithmetical conceptions.
SOCRATES: You follow me excellently,
Theaetetus; that is precisely what I am asking.
THEAETETUS: Indeed, Socrates, I
cannot answer; my only notion is, that these, unlike objects of sense,
have no separate organ, but that the mind, by a power of her own,
contemplates the universals in all things.
SOCRATES: You are a beauty,
Theaetetus, and not ugly, as Theodorus was saying; for he who utters
the beautiful is himself beautiful and good. And besides being
beautiful, you have done me a kindness in releasing me from a very long
discussion, if you are clear that the soul views some things by herself
and others through the bodily organs. For that was my own opinion, and
I wanted you to agree with me.
THEAETETUS: I am quite clear.
SOCRATES: And to which class would
you refer being or essence; for this, of all our notions, is the most
THEAETETUS: I should say, to that
class which the soul aspires to know of herself.
SOCRATES: And would you say this
also of like and unlike, same and other?
SOCRATES: And would you say the same
of the noble and base, and of good and evil?
THEAETETUS: These I conceive to be
notions which are essentially relative, and which the soul also
perceives by comparing in herself things past and present with the
SOCRATES: And does she not perceive
the hardness of that which is hard by the touch, and the softness of
that which is soft equally by the touch?
SOCRATES: But their essence and what
they are, and their opposition to one another, and the essential nature
of this opposition, the soul herself endeavours to decide for us by the
review and comparison of them?
SOCRATES: The simple sensations
which reach the soul through the body are given at birth to men and
animals by nature, but their reflections on the being and use of them
are slowly and hardly gained, if they are ever gained, by education and
SOCRATES: And can a man attain truth
who fails of attaining being?
SOCRATES: And can he who misses the
truth of anything, have a knowledge of that thing?
THEAETETUS: He cannot.
SOCRATES: Then knowledge does not
consist in impressions of sense, but in reasoning about them; in that
only, and not in the mere impression, truth and being can be attained?
SOCRATES: And would you call the two
processes by the same name, when there is so great a difference between
THEAETETUS: That would certainly not
SOCRATES: And what name would you
give to seeing, hearing, smelling, being cold and being hot?
THEAETETUS: I should call all of
them perceiving—what other name could be given to them?
SOCRATES: Perception would be the
collective name of them?
SOCRATES: Which, as we say, has no
part in the attainment of truth any more than of being?
THEAETETUS: Certainly not.
SOCRATES: And therefore not in
science or knowledge?
SOCRATES: Then perception,
Theaetetus, can never be the same as knowledge or science?
THEAETETUS: Clearly not, Socrates;
and knowledge has now been most distinctly proved to be different from
SOCRATES: But the original aim of
our discussion was to find out rather what knowledge is than what it is
not; at the same time we have made some progress, for we no longer seek
for knowledge in perception at all, but in that other process, however
called, in which the mind is alone and engaged with being.
THEAETETUS: You mean, Socrates, if I
am not mistaken, what is called thinking or opining.
SOCRATES: You conceive truly. And
now, my friend, please to begin again at this point; and having wiped
out of your memory all that has preceded, see if you have arrived at
any clearer view, and once more say what is knowledge.
THEAETETUS: I cannot say, Socrates,
that all opinion is knowledge, because there may be a false opinion;
but I will venture to assert, that knowledge is true opinion: let this
then be my reply; and if this is hereafter disproved, I must try to
SOCRATES: That is the way in which
you ought to answer, Theaetetus, and not in your former hesitating
strain, for if we are bold we shall gain one of two advantages; either
we shall find what we seek, or we shall be less likely to think that we
know what we do not know—in either case we shall be richly rewarded.
And now, what are you saying?—Are there two sorts of opinion, one true
and the other false; and do you define knowledge to be the true?
THEAETETUS: Yes, according to my
SOCRATES: Is it still worth our
while to resume the discussion touching opinion?
THEAETETUS: To what are you
SOCRATES: There is a point which
often troubles me, and is a great perplexity to me, both in regard to
myself and others. I cannot make out the nature or origin of the mental
experience to which I refer.
THEAETETUS: Pray what is it?
SOCRATES: How there can be false
opinion—that difficulty still troubles the eye of my mind; and I am
uncertain whether I shall leave the question, or begin over again in a
THEAETETUS: Begin again,
Socrates,—at least if you think that there is the slightest necessity
for doing so. Were not you and Theodorus just now remarking very truly,
that in discussions of this kind we may take our own time?
SOCRATES: You are quite right, and
perhaps there will be no harm in retracing our steps and beginning
again. Better a little which is well done, than a great deal
SOCRATES: Well, and what is the
difficulty? Do we not speak of false opinion, and say that one man
holds a false and another a true opinion, as though there were some
natural distinction between them?
THEAETETUS: We certainly say so.
SOCRATES: All things and everything
are either known or not known. I leave out of view the intermediate
conceptions of learning and forgetting, because they have nothing to do
with our present question.
THEAETETUS: There can be no doubt,
Socrates, if you exclude these, that there is no other alternative but
knowing or not knowing a thing.
SOCRATES: That point being now
determined, must we not say that he who has an opinion, must have an
opinion about something which he knows or does not know?
THEAETETUS: He must.
SOCRATES: He who knows, cannot but
know; and he who does not know, cannot know?
THEAETETUS: Of course.
SOCRATES: What shall we say then?
When a man has a false opinion does he think that which he knows to be
some other thing which he knows, and knowing both, is he at the same
time ignorant of both?
THEAETETUS: That, Socrates, is
SOCRATES: But perhaps he thinks of
something which he does not know as some other thing which he does not
know; for example, he knows neither Theaetetus nor Socrates, and yet he
fancies that Theaetetus is Socrates, or Socrates Theaetetus?
THEAETETUS: How can he?
SOCRATES: But surely he cannot
suppose what he knows to be what he does not know, or what he does not
know to be what he knows?
THEAETETUS: That would be monstrous.
SOCRATES: Where, then, is false
opinion? For if all things are either known or unknown, there can be no
opinion which is not comprehended under this alternative, and so false
opinion is excluded.
THEAETETUS: Most true.
SOCRATES: Suppose that we remove the
question out of the sphere of knowing or not knowing, into that of
being and not-being.
THEAETETUS: What do you mean?
SOCRATES: May we not suspect the
simple truth to be that he who thinks about anything, that which is
not, will necessarily think what is false, whatever in other respects
may be the state of his mind?
THEAETETUS: That, again, is not
SOCRATES: Then suppose some one to
say to us, Theaetetus:—Is it possible for any man to think that which
is not, either as a self-existent substance or as a predicate of
something else? And suppose that we answer, 'Yes, he can, when he
thinks what is not true.'—That will be our answer?
SOCRATES: But is there any parallel
THEAETETUS: What do you mean?
SOCRATES: Can a man see something
and yet see nothing?
SOCRATES: But if he sees any one
thing, he sees something that exists. Do you suppose that what is one
is ever to be found among non-existing things?
THEAETETUS: I do not.
SOCRATES: He then who sees some one
thing, sees something which is?
SOCRATES: And he who hears anything,
hears some one thing, and hears that which is?
SOCRATES: And he who touches
anything, touches something which is one and therefore is?
THEAETETUS: That again is true.
SOCRATES: And does not he who
thinks, think some one thing?
SOCRATES: And does not he who thinks
some one thing, think something which is?
THEAETETUS: I agree.
SOCRATES: Then he who thinks of that
which is not, thinks of nothing?
SOCRATES: And he who thinks of
nothing, does not think at all?
SOCRATES: Then no one can think that
which is not, either as a self-existent substance or as a predicate of
THEAETETUS: Clearly not.
SOCRATES: Then to think falsely is
different from thinking that which is not?
THEAETETUS: It would seem so.
SOCRATES: Then false opinion has no
existence in us, either in the sphere of being or of knowledge?
THEAETETUS: Certainly not.
SOCRATES: But may not the following
be the description of what we express by this name?
SOCRATES: May we not suppose that
false opinion or thought is a sort of heterodoxy; a person may make an
exchange in his mind, and say that one real object is another real
object. For thus he always thinks that which is, but he puts one thing
in place of another; and missing the aim of his thoughts, he may be
truly said to have false opinion.
THEAETETUS: Now you appear to me to
have spoken the exact truth: when a man puts the base in the place of
the noble, or the noble in the place of the base, then he has truly
SOCRATES: I see, Theaetetus, that
your fear has disappeared, and that you are beginning to despise me.
THEAETETUS: What makes you say so?
SOCRATES: You think, if I am not
mistaken, that your 'truly false' is safe from censure, and that I
shall never ask whether there can be a swift which is slow, or a heavy
which is light, or any other self-contradictory thing, which works, not
according to its own nature, but according to that of its opposite. But
I will not insist upon this, for I do not wish needlessly to discourage
you. And so you are satisfied that false opinion is heterodoxy, or the
thought of something else?
THEAETETUS: I am.
SOCRATES: It is possible then upon
your view for the mind to conceive of one thing as another?
SOCRATES: But must not the mind, or
thinking power, which misplaces them, have a conception either of both
objects or of one of them?
SOCRATES: Either together or in
THEAETETUS: Very good.
SOCRATES: And do you mean by
conceiving, the same which I mean?
THEAETETUS: What is that?
SOCRATES: I mean the conversation
which the soul holds with herself in considering of anything. I speak
of what I scarcely understand; but the soul when thinking appears to me
to be just talking—asking questions of herself and answering them,
affirming and denying. And when she has arrived at a decision, either
gradually or by a sudden impulse, and has at last agreed, and does not
doubt, this is called her opinion. I say, then, that to form an opinion
is to speak, and opinion is a word spoken,—I mean, to oneself and in
silence, not aloud or to another: What think you?
THEAETETUS: I agree.
SOCRATES: Then when any one thinks
of one thing as another, he is saying to himself that one thing is
SOCRATES: But do you ever remember
saying to yourself that the noble is certainly base, or the unjust
just; or, best of all—have you ever attempted to convince yourself that
one thing is another? Nay, not even in sleep, did you ever venture to
say to yourself that odd is even, or anything of the kind?
SOCRATES: And do you suppose that
any other man, either in his senses or out of them, ever seriously
tried to persuade himself that an ox is a horse, or that two are one?
THEAETETUS: Certainly not.
SOCRATES: But if thinking is talking
to oneself, no one speaking and thinking of two objects, and
apprehending them both in his soul, will say and think that the one is
the other of them, and I must add, that even you, lover of dispute as
you are, had better let the word 'other' alone (i.e. not insist that
'one' and 'other' are the same (Both words in Greek are called eteron:
compare Parmen.; Euthyd.)). I mean to say, that no one thinks the noble
to be base, or anything of the kind.
THEAETETUS: I will give up the word
'other,' Socrates; and I agree to what you say.
SOCRATES: If a man has both of them
in his thoughts, he cannot think that the one of them is the other?
SOCRATES: Neither, if he has one of
them only in his mind and not the other, can he think that one is the
THEAETETUS: True; for we should have
to suppose that he apprehends that which is not in his thoughts at all.
SOCRATES: Then no one who has either
both or only one of the two objects in his mind can think that the one
is the other. And therefore, he who maintains that false opinion is
heterodoxy is talking nonsense; for neither in this, any more than in
the previous way, can false opinion exist in us.
SOCRATES: But if, Theaetetus, this
is not admitted, we shall be driven into many absurdities.
THEAETETUS: What are they?
SOCRATES: I will not tell you until
I have endeavoured to consider the matter from every point of view. For
I should be ashamed of us if we were driven in our perplexity to admit
the absurd consequences of which I speak. But if we find the solution,
and get away from them, we may regard them only as the difficulties of
others, and the ridicule will not attach to us. On the other hand, if
we utterly fail, I suppose that we must be humble, and allow the
argument to trample us under foot, as the sea-sick passenger is
trampled upon by the sailor, and to do anything to us. Listen, then,
while I tell you how I hope to find a way out of our difficulty.
THEAETETUS: Let me hear.
SOCRATES: I think that we were wrong
in denying that a man could think what he knew to be what he did not
know; and that there is a way in which such a deception is possible.
THEAETETUS: You mean to say, as I
suspected at the time, that I may know Socrates, and at a distance see
some one who is unknown to me, and whom I mistake for him—then the
deception will occur?
SOCRATES: But has not that position
been relinquished by us, because involving the absurdity that we should
know and not know the things which we know?
SOCRATES: Let us make the assertion
in another form, which may or may not have a favourable issue; but as
we are in a great strait, every argument should be turned over and
tested. Tell me, then, whether I am right in saying that you may learn
a thing which at one time you did not know?
THEAETETUS: Certainly you may.
SOCRATES: And another and another?
SOCRATES: I would have you imagine,
then, that there exists in the mind of man a block of wax, which is of
different sizes in different men; harder, moister, and having more or
less of purity in one than another, and in some of an intermediate
THEAETETUS: I see.
SOCRATES: Let us say that this
tablet is a gift of Memory, the mother of the Muses; and that when we
wish to remember anything which we have seen, or heard, or thought in
our own minds, we hold the wax to the perceptions and thoughts, and in
that material receive the impression of them as from the seal of a
ring; and that we remember and know what is imprinted as long as the
image lasts; but when the image is effaced, or cannot be taken, then we
forget and do not know.
THEAETETUS: Very good.
SOCRATES: Now, when a person has
this knowledge, and is considering something which he sees or hears,
may not false opinion arise in the following manner?
THEAETETUS: In what manner?
SOCRATES: When he thinks what he
knows, sometimes to be what he knows, and sometimes to be what he does
not know. We were wrong before in denying the possibility of this.
THEAETETUS: And how would you amend
the former statement?
SOCRATES: I should begin by making a
list of the impossible cases which must be excluded. (1) No one can
think one thing to be another when he does not perceive either of them,
but has the memorial or seal of both of them in his mind; nor can any
mistaking of one thing for another occur, when he only knows one, and
does not know, and has no impression of the other; nor can he think
that one thing which he does not know is another thing which he does
not know, or that what he does not know is what he knows; nor (2) that
one thing which he perceives is another thing which he perceives, or
that something which he perceives is something which he does not
perceive; or that something which he does not perceive is something
else which he does not perceive; or that something which he does not
perceive is something which he perceives; nor again (3) can he think
that something which he knows and perceives, and of which he has the
impression coinciding with sense, is something else which he knows and
perceives, and of which he has the impression coinciding with
sense;—this last case, if possible, is still more inconceivable than
the others; nor (4) can he think that something which he knows and
perceives, and of which he has the memorial coinciding with sense, is
something else which he knows; nor so long as these agree, can he think
that a thing which he knows and perceives is another thing which he
perceives; or that a thing which he does not know and does not
perceive, is the same as another thing which he does not know and does
not perceive;—nor again, can he suppose that a thing which he does not
know and does not perceive is the same as another thing which he does
not know; or that a thing which he does not know and does not perceive
is another thing which he does not perceive:—All these utterly and
absolutely exclude the possibility of false opinion. The only cases, if
any, which remain, are the following.
THEAETETUS: What are they? If you
tell me, I may perhaps understand you better; but at present I am
unable to follow you.
SOCRATES: A person may think that
some things which he knows, or which he perceives and does not know,
are some other things which he knows and perceives; or that some things
which he knows and perceives, are other things which he knows and
THEAETETUS: I understand you less
than ever now.
SOCRATES: Hear me once more,
then:—I, knowing Theodorus, and remembering in my own mind what sort of
person he is, and also what sort of person Theaetetus is, at one time
see them, and at another time do not see them, and sometimes I touch
them, and at another time not, or at one time I may hear them or
perceive them in some other way, and at another time not perceive them,
but still I remember them, and know them in my own mind.
THEAETETUS: Very true.
SOCRATES: Then, first of all, I want
you to understand that a man may or may not perceive sensibly that
which he knows.
SOCRATES: And that which he does not
know will sometimes not be perceived by him and sometimes will be
perceived and only perceived?
THEAETETUS: That is also true.
SOCRATES: See whether you can follow
me better now: Socrates can recognize Theodorus and Theaetetus, but he
sees neither of them, nor does he perceive them in any other way; he
cannot then by any possibility imagine in his own mind that Theaetetus
is Theodorus. Am I not right?
THEAETETUS: You are quite right.
SOCRATES: Then that was the first
case of which I spoke.
SOCRATES: The second case was, that
I, knowing one of you and not knowing the other, and perceiving
neither, can never think him whom I know to be him whom I do not know.
SOCRATES: In the third case, not
knowing and not perceiving either of you, I cannot think that one of
you whom I do not know is the other whom I do not know. I need not
again go over the catalogue of excluded cases, in which I cannot form a
false opinion about you and Theodorus, either when I know both or when
I am in ignorance of both, or when I know one and not the other. And
the same of perceiving: do you understand me?
THEAETETUS: I do.
SOCRATES: The only possibility of
erroneous opinion is, when knowing you and Theodorus, and having on the
waxen block the impression of both of you given as by a seal, but
seeing you imperfectly and at a distance, I try to assign the right
impression of memory to the right visual impression, and to fit this
into its own print: if I succeed, recognition will take place; but if I
fail and transpose them, putting the foot into the wrong shoe—that is
to say, putting the vision of either of you on to the wrong impression,
or if my mind, like the sight in a mirror, which is transferred from
right to left, err by reason of some similar affection, then
'heterodoxy' and false opinion ensues.
THEAETETUS: Yes, Socrates, you have
described the nature of opinion with wonderful exactness.
SOCRATES: Or again, when I know both
of you, and perceive as well as know one of you, but not the other, and
my knowledge of him does not accord with perception—that was the case
put by me just now which you did not understand.
THEAETETUS: No, I did not.
SOCRATES: I meant to say, that when
a person knows and perceives one of you, his knowledge coincides with
his perception, he will never think him to be some other person, whom
he knows and perceives, and the knowledge of whom coincides with his
perception—for that also was a case supposed.
SOCRATES: But there was an omission
of the further case, in which, as we now say, false opinion may arise,
when knowing both, and seeing, or having some other sensible perception
of both, I fail in holding the seal over against the corresponding
sensation; like a bad archer, I miss and fall wide of the mark—and this
is called falsehood.
THEAETETUS: Yes; it is rightly so
SOCRATES: When, therefore,
perception is present to one of the seals or impressions but not to the
other, and the mind fits the seal of the absent perception on the one
which is present, in any case of this sort the mind is deceived; in a
word, if our view is sound, there can be no error or deception about
things which a man does not know and has never perceived, but only in
things which are known and perceived; in these alone opinion turns and
twists about, and becomes alternately true and false;—true when the
seals and impressions of sense meet straight and opposite—false when
they go awry and crooked.
THEAETETUS: And is not that,
Socrates, nobly said?
SOCRATES: Nobly! yes; but wait a
little and hear the explanation, and then you will say so with more
reason; for to think truly is noble and to be deceived is base.
SOCRATES: And the origin of truth
and error is as follows:—When the wax in the soul of any one is deep
and abundant, and smooth and perfectly tempered, then the impressions
which pass through the senses and sink into the heart of the soul, as
Homer says in a parable, meaning to indicate the likeness of the soul
to wax (Kerh Kerhos); these, I say, being pure and clear, and having a
sufficient depth of wax, are also lasting, and minds, such as these,
easily learn and easily retain, and are not liable to confusion, but
have true thoughts, for they have plenty of room, and having clear
impressions of things, as we term them, quickly distribute them into
their proper places on the block. And such men are called wise. Do you
SOCRATES: But when the heart of any
one is shaggy—a quality which the all-wise poet commends, or muddy and
of impure wax, or very soft, or very hard, then there is a
corresponding defect in the mind—the soft are good at learning, but apt
to forget; and the hard are the reverse; the shaggy and rugged and
gritty, or those who have an admixture of earth or dung in their
composition, have the impressions indistinct, as also the hard, for
there is no depth in them; and the soft too are indistinct, for their
impressions are easily confused and effaced. Yet greater is the
indistinctness when they are all jostled together in a little soul,
which has no room. These are the natures which have false opinion; for
when they see or hear or think of anything, they are slow in assigning
the right objects to the right impressions—in their stupidity they
confuse them, and are apt to see and hear and think amiss—and such men
are said to be deceived in their knowledge of objects, and ignorant.
THEAETETUS: No man, Socrates, can
say anything truer than that.
SOCRATES: Then now we may admit the
existence of false opinion in us?
SOCRATES: And of true opinion also?
SOCRATES: We have at length
satisfactorily proven beyond a doubt there are these two sorts of
SOCRATES: Alas, Theaetetus, what a
tiresome creature is a man who is fond of talking!
THEAETETUS: What makes you say so?
SOCRATES: Because I am disheartened
at my own stupidity and tiresome garrulity; for what other term will
describe the habit of a man who is always arguing on all sides of a
question; whose dulness cannot be convinced, and who will never leave
THEAETETUS: But what puts you out of
SOCRATES: I am not only out of
heart, but in positive despair; for I do not know what to answer if any
one were to ask me:—O Socrates, have you indeed discovered that false
opinion arises neither in the comparison of perceptions with one
another nor yet in thought, but in union of thought and perception?
Yes, I shall say, with the complacence of one who thinks that he has
made a noble discovery.
THEAETETUS: I see no reason why we
should be ashamed of our demonstration, Socrates.
SOCRATES: He will say: You mean to
argue that the man whom we only think of and do not see, cannot be
confused with the horse which we do not see or touch, but only think of
and do not perceive? That I believe to be my meaning, I shall reply.
THEAETETUS: Quite right.
SOCRATES: Well, then, he will say,
according to that argument, the number eleven, which is only thought,
can never be mistaken for twelve, which is only thought: How would you
THEAETETUS: I should say that a
mistake may very likely arise between the eleven or twelve which are
seen or handled, but that no similar mistake can arise between the
eleven and twelve which are in the mind.
SOCRATES: Well, but do you think
that no one ever put before his own mind five and seven,—I do not mean
five or seven men or horses, but five or seven in the abstract, which,
as we say, are recorded on the waxen block, and in which false opinion
is held to be impossible; did no man ever ask himself how many these
numbers make when added together, and answer that they are eleven,
while another thinks that they are twelve, or would all agree in
thinking and saying that they are twelve?
THEAETETUS: Certainly not; many
would think that they are eleven, and in the higher numbers the chance
of error is greater still; for I assume you to be speaking of numbers
SOCRATES: Exactly; and I want you to
consider whether this does not imply that the twelve in the waxen block
are supposed to be eleven?
THEAETETUS: Yes, that seems to be
SOCRATES: Then do we not come back
to the old difficulty? For he who makes such a mistake does think one
thing which he knows to be another thing which he knows; but this, as
we said, was impossible, and afforded an irresistible proof of the
non-existence of false opinion, because otherwise the same person would
inevitably know and not know the same thing at the same time.
THEAETETUS: Most true.
SOCRATES: Then false opinion cannot
be explained as a confusion of thought and sense, for in that case we
could not have been mistaken about pure conceptions of thought; and
thus we are obliged to say, either that false opinion does not exist,
or that a man may not know that which he knows;—which alternative do
THEAETETUS: It is hard to determine,
SOCRATES: And yet the argument will
scarcely admit of both. But, as we are at our wits' end, suppose that
we do a shameless thing?
THEAETETUS: What is it?
SOCRATES: Let us attempt to explain
the verb 'to know.'
THEAETETUS: And why should that be
SOCRATES: You seem not to be aware
that the whole of our discussion from the very beginning has been a
search after knowledge, of which we are assumed not to know the nature.
THEAETETUS: Nay, but I am well
SOCRATES: And is it not shameless
when we do not know what knowledge is, to be explaining the verb 'to
know'? The truth is, Theaetetus, that we have long been infected with
logical impurity. Thousands of times have we repeated the words 'we
know,' and 'do not know,' and 'we have or have not science or
knowledge,' as if we could understand what we are saying to one
another, so long as we remain ignorant about knowledge; and at this
moment we are using the words 'we understand,' 'we are ignorant,' as
though we could still employ them when deprived of knowledge or
THEAETETUS: But if you avoid these
expressions, Socrates, how will you ever argue at all?
SOCRATES: I could not, being the man
I am. The case would be different if I were a true hero of dialectic:
and O that such an one were present! for he would have told us to avoid
the use of these terms; at the same time he would not have spared in
you and me the faults which I have noted. But, seeing that we are no
great wits, shall I venture to say what knowing is? for I think that
the attempt may be worth making.
THEAETETUS: Then by all means
venture, and no one shall find fault with you for using the forbidden
SOCRATES: You have heard the common
explanation of the verb 'to know'?
THEAETETUS: I think so, but I do not
remember it at the moment.
SOCRATES: They explain the word 'to
know' as meaning 'to have knowledge.'
SOCRATES: I should like to make a
slight change, and say 'to possess' knowledge.
THEAETETUS: How do the two
SOCRATES: Perhaps there may be no
difference; but still I should like you to hear my view, that you may
help me to test it.
THEAETETUS: I will, if I can.
SOCRATES: I should distinguish
'having' from 'possessing': for example, a man may buy and keep under
his control a garment which he does not wear; and then we should say,
not that he has, but that he possesses the garment.
THEAETETUS: It would be the correct
SOCRATES: Well, may not a man
'possess' and yet not 'have' knowledge in the sense of which I am
speaking? As you may suppose a man to have caught wild birds—doves or
any other birds—and to be keeping them in an aviary which he has
constructed at home; we might say of him in one sense, that he always
has them because he possesses them, might we not?
SOCRATES: And yet, in another sense,
he has none of them; but they are in his power, and he has got them
under his hand in an enclosure of his own, and can take and have them
whenever he likes;—he can catch any which he likes, and let the bird go
again, and he may do so as often as he pleases.
SOCRATES: Once more, then, as in
what preceded we made a sort of waxen figment in the mind, so let us
now suppose that in the mind of each man there is an aviary of all
sorts of birds—some flocking together apart from the rest, others in
small groups, others solitary, flying anywhere and everywhere.
THEAETETUS: Let us imagine such an
aviary—and what is to follow?
SOCRATES: We may suppose that the
birds are kinds of knowledge, and that when we were children, this
receptacle was empty; whenever a man has gotten and detained in the
enclosure a kind of knowledge, he may be said to have learned or
discovered the thing which is the subject of the knowledge: and this is
SOCRATES: And further, when any one
wishes to catch any of these knowledges or sciences, and having taken,
to hold it, and again to let them go, how will he express himself?—will
he describe the 'catching' of them and the original 'possession' in the
same words? I will make my meaning clearer by an example:—You admit
that there is an art of arithmetic?
THEAETETUS: To be sure.
SOCRATES: Conceive this under the
form of a hunt after the science of odd and even in general.
THEAETETUS: I follow.
SOCRATES: Having the use of the art,
the arithmetician, if I am not mistaken, has the conceptions of number
under his hand, and can transmit them to another.
SOCRATES: And when transmitting them
he may be said to teach them, and when receiving to learn them, and
when receiving to learn them, and when having them in possession in the
aforesaid aviary he may be said to know them.
SOCRATES: Attend to what follows:
must not the perfect arithmetician know all numbers, for he has the
science of all numbers in his mind?
SOCRATES: And he can reckon abstract
numbers in his head, or things about him which are numerable?
THEAETETUS: Of course he can.
SOCRATES: And to reckon is simply to
consider how much such and such a number amounts to?
THEAETETUS: Very true.
SOCRATES: And so he appears to be
searching into something which he knows, as if he did not know it, for
we have already admitted that he knows all numbers;—you have heard
these perplexing questions raised?
THEAETETUS: I have.
SOCRATES: May we not pursue the
image of the doves, and say that the chase after knowledge is of two
kinds? one kind is prior to possession and for the sake of possession,
and the other for the sake of taking and holding in the hands that
which is possessed already. And thus, when a man has learned and known
something long ago, he may resume and get hold of the knowledge which
he has long possessed, but has not at hand in his mind.
SOCRATES: That was my reason for
asking how we ought to speak when an arithmetician sets about
numbering, or a grammarian about reading? Shall we say, that although
he knows, he comes back to himself to learn what he already knows?
THEAETETUS: It would be too absurd,
SOCRATES: Shall we say then that he
is going to read or number what he does not know, although we have
admitted that he knows all letters and all numbers?
THEAETETUS: That, again, would be an
SOCRATES: Then shall we say that
about names we care nothing?—any one may twist and turn the words
'knowing' and 'learning' in any way which he likes, but since we have
determined that the possession of knowledge is not the having or using
it, we do assert that a man cannot not possess that which he possesses;
and, therefore, in no case can a man not know that which he knows, but
he may get a false opinion about it; for he may have the knowledge, not
of this particular thing, but of some other;—when the various numbers
and forms of knowledge are flying about in the aviary, and wishing to
capture a certain sort of knowledge out of the general store, he takes
the wrong one by mistake, that is to say, when he thought eleven to be
twelve, he got hold of the ring-dove which he had in his mind, when he
wanted the pigeon.
THEAETETUS: A very rational
SOCRATES: But when he catches the
one which he wants, then he is not deceived, and has an opinion of what
is, and thus false and true opinion may exist, and the difficulties
which were previously raised disappear. I dare say that you agree with
me, do you not?
SOCRATES: And so we are rid of the
difficulty of a man's not knowing what he knows, for we are not driven
to the inference that he does not possess what he possesses, whether he
be or be not deceived. And yet I fear that a greater difficulty is
looking in at the window.
THEAETETUS: What is it?
SOCRATES: How can the exchange of
one knowledge for another ever become false opinion?
THEAETETUS: What do you mean?
SOCRATES: In the first place, how
can a man who has the knowledge of anything be ignorant of that which
he knows, not by reason of ignorance, but by reason of his own
knowledge? And, again, is it not an extreme absurdity that he should
suppose another thing to be this, and this to be another thing;—that,
having knowledge present with him in his mind, he should still know
nothing and be ignorant of all things?—you might as well argue that
ignorance may make a man know, and blindness make him see, as that
knowledge can make him ignorant.
THEAETETUS: Perhaps, Socrates, we
may have been wrong in making only forms of knowledge our birds:
whereas there ought to have been forms of ignorance as well, flying
about together in the mind, and then he who sought to take one of them
might sometimes catch a form of knowledge, and sometimes a form of
ignorance; and thus he would have a false opinion from ignorance, but a
true one from knowledge, about the same thing.
SOCRATES: I cannot help praising
you, Theaetetus, and yet I must beg you to reconsider your words. Let
us grant what you say—then, according to you, he who takes ignorance
will have a false opinion—am I right?
SOCRATES: He will certainly not
think that he has a false opinion?
THEAETETUS: Of course not.
SOCRATES: He will think that his
opinion is true, and he will fancy that he knows the things about which
he has been deceived?
SOCRATES: Then he will think that he
has captured knowledge and not ignorance?
SOCRATES: And thus, after going a
long way round, we are once more face to face with our original
difficulty. The hero of dialectic will retort upon us:—'O my excellent
friends, he will say, laughing, if a man knows the form of ignorance
and the form of knowledge, can he think that one of them which he knows
is the other which he knows? or, if he knows neither of them, can he
think that the one which he knows not is another which he knows not?
or, if he knows one and not the other, can he think the one which he
knows to be the one which he does not know? or the one which he does
not know to be the one which he knows? or will you tell me that there
are other forms of knowledge which distinguish the right and wrong
birds, and which the owner keeps in some other aviaries or graven on
waxen blocks according to your foolish images, and which he may be said
to know while he possesses them, even though he have them not at hand
in his mind? And thus, in a perpetual circle, you will be compelled to
go round and round, and you will make no progress.' What are we to say
in reply, Theaetetus?
THEAETETUS: Indeed, Socrates, I do
not know what we are to say.
SOCRATES: Are not his reproaches
just, and does not the argument truly show that we are wrong in seeking
for false opinion until we know what knowledge is; that must be first
ascertained; then, the nature of false opinion?
THEAETETUS: I cannot but agree with
you, Socrates, so far as we have yet gone.
SOCRATES: Then, once more, what
shall we say that knowledge is?—for we are not going to lose heart as
THEAETETUS: Certainly, I shall not
lose heart, if you do not.
SOCRATES: What definition will be
most consistent with our former views?
THEAETETUS: I cannot think of any
but our old one, Socrates.
SOCRATES: What was it?
THEAETETUS: Knowledge was said by us
to be true opinion; and true opinion is surely unerring, and the
results which follow from it are all noble and good.
SOCRATES: He who led the way into
the river, Theaetetus, said 'The experiment will show;' and perhaps if
we go forward in the search, we may stumble upon the thing which we are
looking for; but if we stay where we are, nothing will come to light.
THEAETETUS: Very true; let us go
forward and try.
SOCRATES: The trail soon comes to an
end, for a whole profession is against us.
THEAETETUS: How is that, and what
profession do you mean?
SOCRATES: The profession of the
great wise ones who are called orators and lawyers; for these persuade
men by their art and make them think whatever they like, but they do
not teach them. Do you imagine that there are any teachers in the world
so clever as to be able to convince others of the truth about acts of
robbery or violence, of which they were not eye-witnesses, while a
little water is flowing in the clepsydra?
THEAETETUS: Certainly not, they can
only persuade them.
SOCRATES: And would you not say that
persuading them is making them have an opinion?
THEAETETUS: To be sure.
SOCRATES: When, therefore, judges
are justly persuaded about matters which you can know only by seeing
them, and not in any other way, and when thus judging of them from
report they attain a true opinion about them, they judge without
knowledge, and yet are rightly persuaded, if they have judged well.
SOCRATES: And yet, O my friend, if
true opinion in law courts and knowledge are the same, the perfect
judge could not have judged rightly without knowledge; and therefore I
must infer that they are not the same.
THEAETETUS: That is a distinction,
Socrates, which I have heard made by some one else, but I had forgotten
it. He said that true opinion, combined with reason, was knowledge, but
that the opinion which had no reason was out of the sphere of
knowledge; and that things of which there is no rational account are
not knowable—such was the singular expression which he used—and that
things which have a reason or explanation are knowable.
SOCRATES: Excellent; but then, how
did he distinguish between things which are and are not 'knowable'? I
wish that you would repeat to me what he said, and then I shall know
whether you and I have heard the same tale.
THEAETETUS: I do not know whether I
can recall it; but if another person would tell me, I think that I
could follow him.
SOCRATES: Let me give you, then, a
dream in return for a dream:—Methought that I too had a dream, and I
heard in my dream that the primeval letters or elements out of which
you and I and all other things are compounded, have no reason or
explanation; you can only name them, but no predicate can be either
affirmed or denied of them, for in the one case existence, in the other
non-existence is already implied, neither of which must be added, if
you mean to speak of this or that thing by itself alone. It should not
be called itself, or that, or each, or alone, or this, or the like; for
these go about everywhere and are applied to all things, but are
distinct from them; whereas, if the first elements could be described,
and had a definition of their own, they would be spoken of apart from
all else. But none of these primeval elements can be defined; they can
only be named, for they have nothing but a name, and the things which
are compounded of them, as they are complex, are expressed by a
combination of names, for the combination of names is the essence of a
definition. Thus, then, the elements or letters are only objects of
perception, and cannot be defined or known; but the syllables or
combinations of them are known and expressed, and are apprehended by
true opinion. When, therefore, any one forms the true opinion of
anything without rational explanation, you may say that his mind is
truly exercised, but has no knowledge; for he who cannot give and
receive a reason for a thing, has no knowledge of that thing; but when
he adds rational explanation, then, he is perfected in knowledge and
may be all that I have been denying of him. Was that the form in which
the dream appeared to you?
SOCRATES: And you allow and maintain
that true opinion, combined with definition or rational explanation, is
SOCRATES: Then may we assume,
Theaetetus, that to-day, and in this casual manner, we have found a
truth which in former times many wise men have grown old and have not
THEAETETUS: At any rate, Socrates, I
am satisfied with the present statement.
SOCRATES: Which is probably
correct—for how can there be knowledge apart from definition and true
opinion? And yet there is one point in what has been said which does
not quite satisfy me.
THEAETETUS: What was it?
SOCRATES: What might seem to be the
most ingenious notion of all:—That the elements or letters are unknown,
but the combination or syllables known.
THEAETETUS: And was that wrong?
SOCRATES: We shall soon know; for we
have as hostages the instances which the author of the argument himself
THEAETETUS: What hostages?
SOCRATES: The letters, which are the
clements; and the syllables, which are the combinations;—he reasoned,
did he not, from the letters of the alphabet?
THEAETETUS: Yes; he did.
SOCRATES: Let us take them and put
them to the test, or rather, test ourselves:—What was the way in which
we learned letters? and, first of all, are we right in saying that
syllables have a definition, but that letters have no definition?
THEAETETUS: I think so.
SOCRATES: I think so too; for,
suppose that some one asks you to spell the first syllable of my
name:—Theaetetus, he says, what is SO?
THEAETETUS: I should reply S and O.
SOCRATES: That is the definition
which you would give of the syllable?
THEAETETUS: I should.
SOCRATES: I wish that you would give
me a similar definition of the S.
THEAETETUS: But how can any one,
Socrates, tell the elements of an element? I can only reply, that S is
a consonant, a mere noise, as of the tongue hissing; B, and most other
letters, again, are neither vowel-sounds nor noises. Thus letters may
be most truly said to be undefined; for even the most distinct of them,
which are the seven vowels, have a sound only, but no definition at
SOCRATES: Then, I suppose, my
friend, that we have been so far right in our idea about knowledge?
THEAETETUS: Yes; I think that we
SOCRATES: Well, but have we been
right in maintaining that the syllables can be known, but not the
THEAETETUS: I think so.
SOCRATES: And do we mean by a
syllable two letters, or if there are more, all of them, or a single
idea which arises out of the combination of them?
THEAETETUS: I should say that we
mean all the letters.
SOCRATES: Take the case of the two
letters S and O, which form the first syllable of my own name; must not
he who knows the syllable, know both of them?
SOCRATES: He knows, that is, the S
SOCRATES: But can he be ignorant of
either singly and yet know both together?
THEAETETUS: Such a supposition,
Socrates, is monstrous and unmeaning.
SOCRATES: But if he cannot know both
without knowing each, then if he is ever to know the syllable, he must
know the letters first; and thus the fine theory has again taken wings
THEAETETUS: Yes, with wonderful
SOCRATES: Yes, we did not keep watch
properly. Perhaps we ought to have maintained that a syllable is not
the letters, but rather one single idea framed out of them, having a
separate form distinct from them.
THEAETETUS: Very true; and a more
likely notion than the other.
SOCRATES: Take care; let us not be
cowards and betray a great and imposing theory.
THEAETETUS: No, indeed.
SOCRATES: Let us assume then, as we
now say, that the syllable is a simple form arising out of the several
combinations of harmonious elements—of letters or of any other
THEAETETUS: Very good.
SOCRATES: And it must have no parts.
SOCRATES: Because that which has
parts must be a whole of all the parts. Or would you say that a whole,
although formed out of the parts, is a single notion different from all
THEAETETUS: I should.
SOCRATES: And would you say that all
and the whole are the same, or different?
THEAETETUS: I am not certain; but,
as you like me to answer at once, I shall hazard the reply, that they
SOCRATES: I approve of your
readiness, Theaetetus, but I must take time to think whether I equally
approve of your answer.
THEAETETUS: Yes; the answer is the
SOCRATES: According to this new
view, the whole is supposed to differ from all?
SOCRATES: Well, but is there any
difference between all (in the plural) and the all (in the singular)?
Take the case of number:—When we say one, two, three, four, five, six;
or when we say twice three, or three times two, or four and two, or
three and two and one, are we speaking of the same or of different
THEAETETUS: Of the same.
SOCRATES: That is of six?
SOCRATES: And in each form of
expression we spoke of all the six?
SOCRATES: Again, in speaking of all
(in the plural) is there not one thing which we express?
THEAETETUS: Of course there is.
SOCRATES: And that is six?
SOCRATES: Then in predicating the
word 'all' of things measured by number, we predicate at the same time
a singular and a plural?
THEAETETUS: Clearly we do.
SOCRATES: Again, the number of the
acre and the acre are the same; are they not?
SOCRATES: And the number of the
stadium in like manner is the stadium?
SOCRATES: And the army is the number
of the army; and in all similar cases, the entire number of anything is
the entire thing?
SOCRATES: And the number of each is
the parts of each?
SOCRATES: Then as many things as
have parts are made up of parts?
SOCRATES: But all the parts are
admitted to be the all, if the entire number is the all?
SOCRATES: Then the whole is not made
up of parts, for it would be the all, if consisting of all the parts?
THEAETETUS: That is the inference.
SOCRATES: But is a part a part of
anything but the whole?
THEAETETUS: Yes, of the all.
SOCRATES: You make a valiant
defence, Theaetetus. And yet is not the all that of which nothing is
SOCRATES: And is not a whole
likewise that from which nothing is absent? but that from which
anything is absent is neither a whole nor all;—if wanting in anything,
both equally lose their entirety of nature.
THEAETETUS: I now think that there
is no difference between a whole and all.
SOCRATES: But were we not saying
that when a thing has parts, all the parts will be a whole and all?
SOCRATES: Then, as I was saying
before, must not the alternative be that either the syllable is not the
letters, and then the letters are not parts of the syllable, or that
the syllable will be the same with the letters, and will therefore be
equally known with them?
THEAETETUS: You are right.
SOCRATES: And, in order to avoid
this, we suppose it to be different from them?
SOCRATES: But if letters are not
parts of syllables, can you tell me of any other parts of syllables,
which are not letters?
THEAETETUS: No, indeed, Socrates;
for if I admit the existence of parts in a syllable, it would be
ridiculous in me to give up letters and seek for other parts.
SOCRATES: Quite true, Theaetetus,
and therefore, according to our present view, a syllable must surely be
some indivisible form?
SOCRATES: But do you remember, my
friend, that only a little while ago we admitted and approved the
statement, that of the first elements out of which all other things are
compounded there could be no definition, because each of them when
taken by itself is uncompounded; nor can one rightly attribute to them
the words 'being' or 'this,' because they are alien and inappropriate
words, and for this reason the letters or elements were indefinable and
THEAETETUS: I remember.
SOCRATES: And is not this also the
reason why they are simple and indivisible? I can see no other.
THEAETETUS: No other reason can be
SOCRATES: Then is not the syllable
in the same case as the elements or letters, if it has no parts and is
THEAETETUS: To be sure.
SOCRATES: If, then, a syllable is a
whole, and has many parts or letters, the letters as well as the
syllable must be intelligible and expressible, since all the parts are
acknowledged to be the same as the whole?
SOCRATES: But if it be one and
indivisible, then the syllables and the letters are alike undefined and
unknown, and for the same reason?
THEAETETUS: I cannot deny that.
SOCRATES: We cannot, therefore,
agree in the opinion of him who says that the syllable can be known and
expressed, but not the letters.
THEAETETUS: Certainly not; if we may
trust the argument.
SOCRATES: Well, but will you not be
equally inclined to disagree with him, when you remember your own
experience in learning to read?
THEAETETUS: What experience?
SOCRATES: Why, that in learning you
were kept trying to distinguish the separate letters both by the eye
and by the ear, in order that, when you heard them spoken or saw them
written, you might not be confused by their position.
THEAETETUS: Very true.
SOCRATES: And is the education of
the harp-player complete unless he can tell what string answers to a
particular note; the notes, as every one would allow, are the elements
or letters of music?
SOCRATES: Then, if we argue from the
letters and syllables which we know to other simples and compounds, we
shall say that the letters or simple elements as a class are much more
certainly known than the syllables, and much more indispensable to a
perfect knowledge of any subject; and if some one says that the
syllable is known and the letter unknown, we shall consider that either
intentionally or unintentionally he is talking nonsense?
SOCRATES: And there might be given
other proofs of this belief, if I am not mistaken. But do not let us in
looking for them lose sight of the question before us, which is the
meaning of the statement, that right opinion with rational definition
or explanation is the most perfect form of knowledge.
THEAETETUS: We must not.
SOCRATES: Well, and what is the
meaning of the term 'explanation'? I think that we have a choice of
THEAETETUS: What are they?
SOCRATES: In the first place, the
meaning may be, manifesting one's thought by the voice with verbs and
nouns, imaging an opinion in the stream which flows from the lips, as
in a mirror or water. Does not explanation appear to be of this nature?
THEAETETUS: Certainly; he who so
manifests his thought, is said to explain himself.
SOCRATES: And every one who is not
born deaf or dumb is able sooner or later to manifest what he thinks of
anything; and if so, all those who have a right opinion about anything
will also have right explanation; nor will right opinion be anywhere
found to exist apart from knowledge.
SOCRATES: Let us not, therefore,
hastily charge him who gave this account of knowledge with uttering an
unmeaning word; for perhaps he only intended to say, that when a person
was asked what was the nature of anything, he should be able to answer
his questioner by giving the elements of the thing.
THEAETETUS: As for example,
SOCRATES: As, for example, when
Hesiod says that a waggon is made up of a hundred planks. Now, neither
you nor I could describe all of them individually; but if any one asked
what is a waggon, we should be content to answer, that a waggon
consists of wheels, axle, body, rims, yoke.
SOCRATES: And our opponent will
probably laugh at us, just as he would if we professed to be
grammarians and to give a grammatical account of the name of
Theaetetus, and yet could only tell the syllables and not the letters
of your name—that would be true opinion, and not knowledge; for
knowledge, as has been already remarked, is not attained until,
combined with true opinion, there is an enumeration of the elements out
of which anything is composed.
SOCRATES: In the same general way,
we might also have true opinion about a waggon; but he who can describe
its essence by an enumeration of the hundred planks, adds rational
explanation to true opinion, and instead of opinion has art and
knowledge of the nature of a waggon, in that he attains to the whole
through the elements.
THEAETETUS: And do you not agree in
that view, Socrates?
SOCRATES: If you do, my friend; but
I want to know first, whether you admit the resolution of all things
into their elements to be a rational explanation of them, and the
consideration of them in syllables or larger combinations of them to be
irrational—is this your view?
SOCRATES: Well, and do you conceive
that a man has knowledge of any element who at one time affirms and at
another time denies that element of something, or thinks that the same
thing is composed of different elements at different times?
THEAETETUS: Assuredly not.
SOCRATES: And do you not remember
that in your case and in that of others this often occurred in the
process of learning to read?
THEAETETUS: You mean that I mistook
the letters and misspelt the syllables?
THEAETETUS: To be sure; I perfectly
remember, and I am very far from supposing that they who are in this
condition have knowledge.
SOCRATES: When a person at the time
of learning writes the name of Theaetetus, and thinks that he ought to
write and does write Th and e; but, again, meaning to write the name of
Theododorus, thinks that he ought to write and does write T and e—can
we suppose that he knows the first syllables of your two names?
THEAETETUS: We have already admitted
that such a one has not yet attained knowledge.
SOCRATES: And in like manner be may
enumerate without knowing them the second and third and fourth
syllables of your name?
THEAETETUS: He may.
SOCRATES: And in that case, when he
knows the order of the letters and can write them out correctly, he has
SOCRATES: But although we admit that
he has right opinion, he will still be without knowledge?
SOCRATES: And yet he will have
explanation, as well as right opinion, for he knew the order of the
letters when he wrote; and this we admit to be explanation.
SOCRATES: Then, my friend, there is
such a thing as right opinion united with definition or explanation,
which does not as yet attain to the exactness of knowledge.
THEAETETUS: It would seem so.
SOCRATES: And what we fancied to be
a perfect definition of knowledge is a dream only. But perhaps we had
better not say so as yet, for were there not three explanations of
knowledge, one of which must, as we said, be adopted by him who
maintains knowledge to be true opinion combined with rational
explanation? And very likely there may be found some one who will not
prefer this but the third.
THEAETETUS: You are quite right;
there is still one remaining. The first was the image or expression of
the mind in speech; the second, which has just been mentioned, is a way
of reaching the whole by an enumeration of the elements. But what is
the third definition?
SOCRATES: There is, further, the
popular notion of telling the mark or sign of difference which
distinguishes the thing in question from all others.
THEAETETUS: Can you give me any
example of such a definition?
SOCRATES: As, for example, in the
case of the sun, I think that you would be contented with the statement
that the sun is the brightest of the heavenly bodies which revolve
about the earth.
SOCRATES: Understand why:—the reason
is, as I was just now saying, that if you get at the difference and
distinguishing characteristic of each thing, then, as many persons
affirm, you will get at the definition or explanation of it; but while
you lay hold only of the common and not of the characteristic notion,
you will only have the definition of those things to which this common
THEAETETUS: I understand you, and
your account of definition is in my judgment correct.
SOCRATES: But he, who having right
opinion about anything, can find out the difference which distinguishes
it from other things will know that of which before he had only an
THEAETETUS: Yes; that is what we are
SOCRATES: Nevertheless, Theaetetus,
on a nearer view, I find myself quite disappointed; the picture, which
at a distance was not so bad, has now become altogether unintelligible.
THEAETETUS: What do you mean?
SOCRATES: I will endeavour to
explain: I will suppose myself to have true opinion of you, and if to
this I add your definition, then I have knowledge, but if not, opinion
SOCRATES: The definition was assumed
to be the interpretation of your difference.
SOCRATES: But when I had only
opinion, I had no conception of your distinguishing characteristics.
THEAETETUS: I suppose not.
SOCRATES: Then I must have conceived
of some general or common nature which no more belonged to you than to
SOCRATES: Tell me, now—How in that
case could I have formed a judgment of you any more than of any one
else? Suppose that I imagine Theaetetus to be a man who has nose, eyes,
and mouth, and every other member complete; how would that enable me to
distinguish Theaetetus from Theodorus, or from some outer barbarian?
THEAETETUS: How could it?
SOCRATES: Or if I had further
conceived of you, not only as having nose and eyes, but as having a
snub nose and prominent eyes, should I have any more notion of you than
of myself and others who resemble me?
THEAETETUS: Certainly not.
SOCRATES: Surely I can have no
conception of Theaetetus until your snub-nosedness has left an
impression on my mind different from the snub-nosedness of all others
whom I have ever seen, and until your other peculiarities have a like
distinctness; and so when I meet you to-morrow the right opinion will
THEAETETUS: Most true.
SOCRATES: Then right opinion implies
the perception of differences?
SOCRATES: What, then, shall we say
of adding reason or explanation to right opinion? If the meaning is,
that we should form an opinion of the way in which something differs
from another thing, the proposal is ridiculous.
THEAETETUS: How so?
SOCRATES: We are supposed to acquire
a right opinion of the differences which distinguish one thing from
another when we have already a right opinion of them, and so we go
round and round:—the revolution of the scytal, or pestle, or any other
rotatory machine, in the same circles, is as nothing compared with such
a requirement; and we may be truly described as the blind directing the
blind; for to add those things which we already have, in order that we
may learn what we already think, is like a soul utterly benighted.
THEAETETUS: Tell me; what were you
going to say just now, when you asked the question?
SOCRATES: If, my boy, the argument,
in speaking of adding the definition, had used the word to 'know,' and
not merely 'have an opinion' of the difference, this which is the most
promising of all the definitions of knowledge would have come to a
pretty end, for to know is surely to acquire knowledge.
SOCRATES: And so, when the question
is asked, What is knowledge? this fair argument will answer 'Right
opinion with knowledge,'—knowledge, that is, of difference, for this,
as the said argument maintains, is adding the definition.
THEAETETUS: That seems to be true.
SOCRATES: But how utterly foolish,
when we are asking what is knowledge, that the reply should only be,
right opinion with knowledge of difference or of anything! And so,
Theaetetus, knowledge is neither sensation nor true opinion, nor yet
definition and explanation accompanying and added to true opinion?
THEAETETUS: I suppose not.
SOCRATES: And are you still in
labour and travail, my dear friend, or have you brought all that you
have to say about knowledge to the birth?
THEAETETUS: I am sure, Socrates,
that you have elicited from me a good deal more than ever was in me.
SOCRATES: And does not my art show
that you have brought forth wind, and that the offspring of your brain
are not worth bringing up?
THEAETETUS: Very true.
SOCRATES: But if, Theaetetus, you
should ever conceive afresh, you will be all the better for the present
investigation, and if not, you will be soberer and humbler and gentler
to other men, and will be too modest to fancy that you know what you do
not know. These are the limits of my art; I can no further go, nor do I
know aught of the things which great and famous men know or have known
in this or former ages. The office of a midwife I, like my mother, have
received from God; she delivered women, I deliver men; but they must be
young and noble and fair.
And now I have to go to the porch of
the King Archon, where I am to meet Meletus and his indictment.
To-morrow morning, Theodorus, I shall hope to see you again at this