on.

THEAETETUS: How?

STRANGER: If we can discover a line which divides ignorance into two
halves. For a division of ignorance into two parts will certainly
imply that the art of instruction is also twofold, answering to the two
divisions of ignorance.

THEAETETUS: Well, and do you see what you are looking for?

STRANGER: I do seem to myself to see one very large and bad sort of
ignorance which is quite separate, and may be weighed in the scale
against all other sorts of ignorance put together.

THEAETETUS: What is it?

STRANGER: When a person supposes that he knows, and does not know; this
appears to be the great source of all the errors of the intellect.

THEAETETUS: True.

STRANGER: And this, if I am not mistaken, is the kind of ignorance which
specially earns the title of stupidity.

THEAETETUS: True.

STRANGER: What name, then, shall be given to the sort of instruction
which gets rid of this?

THEAETETUS: The instruction which you mean, Stranger, is, I should
imagine, not the teaching of handicraft arts, but what, thanks to us,
has been termed education in this part the world.

STRANGER: Yes, Theaetetus, and by nearly all Hellenes. But we have still
to consider whether education admits of any further division.

THEAETETUS: We have.

STRANGER: I think that there is a point at which such a division is
possible.

THEAETETUS: Where?

STRANGER: Of education, one method appears to be rougher, and another
smoother.

THEAETETUS: How are we to distinguish the two?

STRANGER: There is the time-honoured mode which our fathers commonly
practised towards their sons, and which is still adopted by many--either
of roughly reproving their errors, or of gently advising them;
which varieties may be correctly included under the general term of
admonition.

THEAETETUS: True.

STRANGER: But whereas some appear to have arrived at the conclusion that
all ignorance is involuntary, and that no one who thinks himself wise is
willing to learn any of those things in which he is conscious of his
own cleverness, and that the admonitory sort of instruction gives much
trouble and does little good--

THEAETETUS: There they are quite right.

STRANGER: Accordingly, they set to work to eradicate the spirit of
conceit in another way.

THEAETETUS: In what way?

STRANGER: They cross-examine a man's words, when he thinks that he is
saying something and is really saying nothing, and easily convict him
of inconsistencies