reak down. The first syllable of Socrates' name
is SO. But what is SO? Two letters, S and O, a sibilant and a vowel,
of which no further explanation can be given. And how can any one
be ignorant of either of them, and yet know both of them? There is,
however, another alternative:--We may suppose that the syllable has a
separate form or idea distinct from the letters or parts. The all of the
parts may not be the whole. Theaetetus is very much inclined to adopt
this suggestion, but when interrogated by Socrates he is unable to
draw any distinction between the whole and all the parts. And if the
syllables have no parts, then they are those original elements of which
there is no explanation. But how can the syllable be known if the letter
remains unknown? In learning to read as children, we are first taught
the letters and then the syllables. And in music, the notes, which
are the letters, have a much more distinct meaning to us than the
combination of them.

Once more, then, we must ask the meaning of the statement, that
'Knowledge is right opinion, accompanied by explanation or definition.'
Explanation may mean, (1) the reflection or expression of a man's
thoughts--but every man who is not deaf and dumb is able to express his
thoughts--or (2) the enumeration of the elements of which anything is
composed. A man may have a true opinion about a waggon, but then, and
then only, has he knowledge of a waggon when he is able to enumerate
the hundred planks of Hesiod. Or he may know the syllables of the name
Theaetetus, but not the letters; yet not until he knows both can he be
said to have knowledge as well as opinion. But on the other hand he may
know the syllable 'The' in the name Theaetetus, yet he may be mistaken
about the same syllable in the name Theodorus, and in learning to read
we often make such mistakes. And even if he could write out all the
letters and syllables of your name in order, still he would only have
right opinion. Yet there may be a third meaning of the definition,
besides the image or expression of the mind, and the enumeration of the
elements, viz. (3) perception of difference.

For example, I may see a man who has eyes, nose, and mouth;--that will
not distinguish him from any other man. Or he may have a snub-nose and
prominent eyes;--that will not distinguish him from myself and you and
others who are like me. But when I see a certain kind of snub-nosedness,
then I recognize Theaetetus. And having this