Theaetetus
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 universal?
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?
THEAETETUS: Yes.
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 future.
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?
THEAETETUS: Yes.
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?
THEAETETUS: Certainly.
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 long experience.
THEAETETUS: Assuredly.
SOCRATES: And can a man attain truth who fails of attaining being?
THEAETETUS: Impossible.
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?
THEAETETUS: Clearly.
SOCRATES: And would you call the two processes by the same name, when
there is so great a difference between them?
THEAETETUS: That would certainly not be right.
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?
THEAETETUS: Certainly.
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?
THEAETETUS: No.
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 perception.
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 find another.
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 present view.
SOCRATES: Is it still worth our while to resume the discussion touching
opinion?
THEAETETUS: To what are you alluding?
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 new way.
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 imperfectly.
THEAETETUS: Certainly.
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 impossible.
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 unlikely, Socrates.
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?
THEAETETUS: Yes.
SOCRATES: But is there any parallel to this?
THEAETETUS: What do you mean?
SOCRATES: Can a man see something and yet see nothing?
THEAETETUS: Impossible.
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?
THEAETETUS: Clearly.
SOCRATES: And he who hears anything, hears some one thing, and hears
that which is?
THEAETETUS: Yes.
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?
THEAETETUS: Certainly.
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?
THEAETETUS: Clearly.
SOCRATES: And he who thinks of nothing, does not think at all?
THEAETETUS: Obviously.
SOCRATES: Then no one can think that which is not, either as a
self-existent substance or as a predicate of something else?
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?
THEAETETUS: What?
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 false opinion.
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?
THEAETETUS: True.
SOCRATES: But must not the mind, or thinking power, which misplaces
them, have a conception either of both objects or of one of them?
THEAETETUS: Certainly.
SOCRATES: Either together or in succession?
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 another?
THEAETETUS: Yes.
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