sophist   

but you must try and tell me the name of the other.
Theaet. He must be the Sophist, whom we are seeking; no other name
can possibly be right.
Str. No other; and so this trader in virtue again turns out to be
our friend the Sophist, whose art may now be traced from the art of
acquisition through exchange, trade, merchandise, to a merchandise
of the soul which is concerned with speech and the knowledge of
virtue.
Theaet. Quite true.
Str. And there may be a third reappearance of him;-for he may have
settled down in a city, and may fabricate as well as buy these same
wares, intending to live by selling them, and he would still
be called
a Sophist?
Theaet. Certainly.
Str. Then that part of acquisitive art which exchanges, and of
exchange which either sells a man's own productions or retails those
of others; as the case may be, and in either way sells the knowledge
of virtue, you would again term Sophistry?
Theaet. I must, if I am to keep pace with the argument.
Str. Let us consider once more whether there may not be yet
another aspect of sophistry.
Theaet. What is it?
Str. In the acquisitive there was a subdivision of the combative
or fighting art.
Theaet. There was.
Str. Perhaps we had better divide it.
Theaet. What shall be the divisions?
Str. There shall be one division of the competitive, and another
of the pugnacious.
Theaet. Very good.
Str. That part of the pugnacious which is contest of
bodily strength
may be properly called by some such name as violent.
Theaet. True.
Str. And when the war is one of words, it may be termed
controversy?
Theaet. Yes.
Str. And controversy may be of two kinds.
Theaet. What are they?
Str. When long speeches are answered by long speeches, and there
is public discussion about the just and unjust, that is forensic
controversy.
Theaet. Yes.
Str. And there is a private sort of controversy, which is cut up
into questions and answers, and this is commonly called disputation?
Theaet. Yes, that is the name.
Str. And of disputation, that sort which is only a discussion
about contracts, and is carried on at random, and without rules-art,
is recognized by the reasoning faculty to be a distinct
class, but has
hitherto had no distinctive name, and does not deserve to receive
one from us.
Theaet. No; for the different sorts of it are too minute and
heterogeneous.
Str. But that which proceeds by rules of art to dispute about
justice and injustice in their own nature, and about things in
general, we have been accustomed to call argumentation (Eristic)?
Theaet. Certainly.
Str. And of argumentation, one sort wastes money, and the other
makes money.
Theaet. Very true.
Str. Suppose we try and give to each of these two classes a name.
Theaet. Let us do so.