Theaetetus | Page 5

wonder, and is
almost too modest to speak, but, encouraged by Socrates, he rises to the
occasion, and grows full of interest and enthusiasm about the great
question. Like a youth, he has not finally made up his mind, and is very
ready to follow the lead of Socrates, and to enter into each successive
phase of the discussion which turns up. His great dialectical talent is
shown in his power of drawing distinctions, and of foreseeing the
consequences of his own answers. The enquiry about the nature of
knowledge is not new to him; long ago he has felt the 'pang of
philosophy,' and has experienced the youthful intoxication which is
depicted in the Philebus. But he has hitherto been unable to make the
transition from mathematics to metaphysics. He can form a general
conception of square and oblong numbers, but he is unable to attain a
similar expression of knowledge in the abstract. Yet at length he begins
to recognize that there are universal conceptions of being, likeness,
sameness, number, which the mind contemplates in herself, and with
the help of Socrates is conducted from a theory of sense to a theory of
ideas.
There is no reason to doubt that Theaetetus was a real person, whose
name survived in the next generation. But neither can any importance
be attached to the notices of him in Suidas and Proclus, which are
probably based on the mention of him in Plato. According to a
confused statement in Suidas, who mentions him twice over, first, as a
pupil of Socrates, and then of Plato, he is said to have written the first

work on the Five Solids. But no early authority cites the work, the
invention of which may have been easily suggested by the division of
roots, which Plato attributes to him, and the allusion to the backward
state of solid geometry in the Republic. At any rate, there is no
occasion to recall him to life again after the battle of Corinth, in order
that we may allow time for the completion of such a work (Muller). We
may also remark that such a supposition entirely destroys the pathetic
interest of the introduction.
Theodorus, the geometrician, had once been the friend and disciple of
Protagoras, but he is very reluctant to leave his retirement and defend
his old master. He is too old to learn Socrates' game of question and
answer, and prefers the digressions to the main argument, because he
finds them easier to follow. The mathematician, as Socrates says in the
Republic, is not capable of giving a reason in the same manner as the
dialectician, and Theodorus could not therefore have been appropriately
introduced as the chief respondent. But he may be fairly appealed to,
when the honour of his master is at stake. He is the 'guardian of his
orphans,' although this is a responsibility which he wishes to throw
upon Callias, the friend and patron of all Sophists, declaring that he
himself had early 'run away' from philosophy, and was absorbed in
mathematics. His extreme dislike to the Heraclitean fanatics, which
may be compared with the dislike of Theaetetus to the materialists, and
his ready acceptance of the noble words of Socrates, are noticeable
traits of character.
The Socrates of the Theaetetus is the same as the Socrates of the earlier
dialogues. He is the invincible disputant, now advanced in years, of the
Protagoras and Symposium; he is still pursuing his divine mission, his
'Herculean labours,' of which he has described the origin in the
Apology; and he still hears the voice of his oracle, bidding him receive
or not receive the truant souls. There he is supposed to have a mission
to convict men of self-conceit; in the Theaetetus he has assigned to him
by God the functions of a man-midwife, who delivers men of their
thoughts, and under this character he is present throughout the dialogue.
He is the true prophet who has an insight into the natures of men, and
can divine their future; and he knows that sympathy is the secret power
which unlocks their thoughts. The hit at Aristides, the son of
Lysimachus, who was specially committed to his charge in the Laches,

may be remarked by the way. The attempt to discover the definition of
knowledge is in accordance with the character of Socrates as he is
described in the Memorabilia, asking What is justice? what is
temperance? and the like. But there is no reason to suppose that he
would have analyzed the nature of perception, or traced the connexion
of Protagoras and Heracleitus, or have raised the difficulty respecting
false opinion. The humorous illustrations, as well as the serious
thoughts, run through the dialogue. The snubnosedness of Theaetetus, a
characteristic which he shares with Socrates, and the