SOCRATES: Well, but have we been right in maintaining that the syllables can be known, but not the letters?
THEAETETUS: I think so.
SOCRATES: 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?
THEAETETUS: I should say that we mean all the letters.
SOCRATES: 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?
THEAETETUS: Certainly.
SOCRATES: He knows, that is, the S and O?
THEAETETUS: Yes.
SOCRATES: But can he be ignorant of either singly and yet know both together?
THEAETETUS: Such a supposition, Socrates, is monstrous and unmeaning.