Plato does not really mean to say that the Sophist or the Statesman can be caught in this way.
The seller of the arts may be called an art-seller; the seller of virtue, a Sophist.
And now, leaving him, we will return to our pursuit of the Sophist.
The Sophist, then, has not real knowledge; he is only an imitator, or image-maker.
And this is Plato's reply, both in the Cratylus ...