eeing you both
imperfectly and at a distance, put the foot in the wrong shoe--that
is to say, put the seal or stamp on the wrong object: or 2ndly, when
knowing both of you I only see one; or when, seeing and knowing you
both, I fail to identify the impression and the object. But there could
be no error when perception and knowledge correspond.

The waxen block in the heart of a man's soul, as I may say in the words
of Homer, who played upon the words ker and keros, may be smooth and
deep, and large enough, and then the signs are clearly marked and
lasting, and do not get confused. But in the 'hairy heart,' as the
all-wise poet sings, when the wax is muddy or hard or moist, there is
a corresponding confusion and want of retentiveness; in the muddy and
impure there is indistinctness, and still more in the hard, for there
the impressions have no depth of wax, and in the moist they are too
soon effaced. Yet greater is the indistinctness when they are all jolted
together in a little soul, which is narrow and has no room. These are
the sort of natures which have false opinion; from stupidity they see
and hear and think amiss; and this is falsehood and ignorance. Error,
then, is a confusion of thought and sense.

Theaetetus is delighted with this explanation. But Socrates has no
sooner found the new solution than he sinks into a fit of despondency.
For an objection occurs to him:--May there not be errors where there is
no confusion of mind and sense? e.g. in numbers. No one can confuse
the man whom he has in his thoughts with the horse which he has in his
thoughts, but he may err in the addition of five and seven. And observe
that these are purely mental conceptions. Thus we are involved once more
in the dilemma of saying, either that there is no such thing as false
opinion, or that a man knows what he does not know.

We are at our wit's end, and may therefore be excused for making a
bold diversion. All this time we have been repeating the words 'know,'
'understand,' yet we do not know what knowledge is. 'Why, Socrates,
how can you argue at all without using them?' Nay, but the true hero
of dialectic would have forbidden me to use them until I had explained
them. And I must explain them now. The verb 'to know' has two senses,
to have and to possess knowledge, and I distinguish 'having' from
'possessing.' A man may possess a garment which he does not wear; or he
may have wild birds in an aviary; these in one sense he possesse