nd 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.

THEAETETUS: True.

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 called.

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