nd yet surely you and Theodorus had
better reflect whether probability is a safe guide. Theodorus would be
a bad geometrician if he had nothing better to offer.'...Theaetetus is
affected by the appeal to geometry, and Socrates is induced by him to
put the question in a new form. He proceeds as follows:--'Should we say
that we know what we see and hear,--e.g. the sound of words or the sight
of letters in a foreign tongue?'

'We should say that the figures of the letters, and the pitch of the
voice in uttering them, were known to us, but not the meaning of them.'

'Excellent; I want you to grow, and therefore I will leave that answer
and ask another question: Is not seeing perceiving?' 'Very true.' 'And
he who sees knows?' 'Yes.' 'And he who remembers, remembers that which
he sees and knows?' 'Very true.' 'But if he closes his eyes, does he not
remember?' 'He does.' 'Then he may remember and not see; and if seeing
is knowing, he may remember and not know. Is not this a "reductio ad
absurdum" of the hypothesis that knowledge is sensible perception? Yet
perhaps we are crowing too soon; and if Protagoras, "the father of the
myth," had been alive, the result might have been very different. But he
is dead, and Theodorus, whom he left guardian of his "orphan," has not
been very zealous in defending him.'

Theodorus objects that Callias is the true guardian, but he hopes that
Socrates will come to the rescue. Socrates prefaces his defence by
resuming the attack. He asks whether a man can know and not know at the
same time? 'Impossible.' Quite possible, if you maintain that seeing is
knowing. The confident adversary, suiting the action to the word, shuts
one of your eyes; and now, says he, you see and do not see, but do
you know and not know? And a fresh opponent darts from his ambush, and
transfers to knowledge the terms which are commonly applied to sight.
He asks whether you can know near and not at a distance; whether you can
have a sharp and also a dull knowledge. While you are wondering at his
incomparable wisdom, he gets you into his power, and you will not escape
until you have come to an understanding with him about the money which
is to be paid for your release.

But Protagoras has not yet made his defence; and already he may be heard
contemptuously replying that he is not responsible for the admissions
which were made by a boy, who could not foresee the coming move, and
therefore had answered in a manner which enabl