The first rule of good speaking is to know and speak the truth; as a
Spartan proverb says, 'true art is truth'; whereas rhetoric is an art of
enchantment, which makes things appear good and evil, like and unlike, as
the speaker pleases. Its use is not confined, as people commonly suppose,
to arguments in the law courts and speeches in the assembly; it is rather a
part of the art of disputation, under which are included both the rules of
Gorgias and the eristic of Zeno. But it is not wholly devoid of truth.
Superior knowledge enables us to deceive another by the help of
resemblances, and to escape from such a deception when employed against
ourselves. We see therefore that even in rhetoric an element of truth is
required. For if we do not know the truth, we can neither make the gradual
departures from truth by which men are most easily deceived, nor guard
ourselves against deception.

Socrates then proposes that they shall use the two speeches as
illustrations of the art of rhetoric; first distinguishing between the
debatable and undisputed class of subjects. In the debatable class there
ought to be a definition of all disputed matters. But there was no such
definition in the speech of Lysias; nor is there any order or connection in
his words any more than in a nursery rhyme. With this he compares the
regular divisions of the other speech, which was his own (and yet not his
own, for the local deities must have inspired him). Although only a
playful composition, it will be found to embody two principles: first, that
of synthesis or the comprehension of parts in a whole; secondly, analysis,
or the resolution of the whole into parts. These are the processes of
division and generalization which are so dear to the dialectician, that
king of men. They are effected by dialectic, and not by rhetoric, of which
the remains are but scanty after order and arrangement have been
subtracted. There is nothing left but a heap of 'ologies' and other
technical terms invented by Polus, Theodorus, Evenus, Tisias, Gorgias, and