ss 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 be re-called?

THEAETETUS: Most true.

SOCRATES: Then right opinion implies the perception of differences?

THEAETETUS: Clearly.

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.

THEAETETUS: True.

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 brin