Soc. And you allow and maintain that true opinion, combined with definition or rational explanation, is knowledge ?
Theaet. Exactly.
Soc. Then may we assume, Theaetetus, that to-day, and in this casual manner, we have found a truth which in former times many wise men have grown old and have not found ?
Theaet. At any rate, Socrates, I am satisfied with the present statement.
Soc. Which is probably correct — for how can there be knowledge apart from definition and true opinion ? And yet there is one point in what has been said which does not quite satisfy me.
Theaet. What was it ?
Soc. What might seem to be the most ingenious notion of all : — That the elements or letters are unknown, but the combination or syllables known.
Theaet. And was that wrong ?
Soc. We shall soon know ; for we have as hostages the instances which the author of the argument himself used.
Theaet. What hostages ?
Soc. The letters, which are the clements ; and the syllables, which are the combinations ; — he reasoned, did he not, from the letters of the alphabet ?
Theaet. Yes ; he did.
Soc. Let us take them and put them to the test, or rather, test ourselves : — What was the way in which we learned letters ? and, first of all, are we right in saying that syllables have a definition, but that letters have no definition ?
Theaet. I think so.
Soc. I think so too ; for, suppose that some one asks you to spell the first syllable of my name : — Theaetetus, he says, what is SO ?
Theaet. I should reply S and O.
Soc. That is the definition which you would give of the syllable ?
Theaet. I should.
Soc. I wish that you would give me a similar definition of the S.
Theaet. But how can any one, Socrates, tell the elements of an element ? I can only reply, that S is a consonant, a mere noise, as of the tongue hissing ; B, and most other letters, again, are neither vowel-sounds nor noises. Thus letters may be most truly said to be undefined ; for even the most distinct of them, which are the seven vowels, have a sound only, but no definition at all.
Soc. Then, I suppose, my friend, that we have been so far right in our idea about knowledge ?
Theaet. Yes ; I think that we have.
Soc. Well, but have we been right in maintaining that the syllables can be known, but not the letters ?
Theaet. I think so.
Soc. And do we mean by a syllable two letters, or if there are more, all of them, or a single idea which arises out of the combination of them ?
Theaet. I should say that we mean all the letters.
Soc. Take the case of the two letters S and O, which form the first syllable of my own name ; must not he who knows the syllable, know both of them ?
Theaet. Certainly.
Soc. He knows, that is, the S and O ?
Theaet. Yes.
Soc. But can he be ignorant of either singly and yet know both together ?
Theaet. Such a supposition, Socrates, is monstrous and unmeaning.
Soc. But if he cannot know both without knowing each, then if he is ever to know the syllable, he must know the letters first ; and thus the fine theory has again taken wings and departed.
Theaet. Yes, with wonderful celerity.