And who are the ministers of the purification? Sophists I may not call them. Yet they bear about the same likeness to Sophists as the dog, who is the gentlest of animals, does to the wolf, who is the fiercest. Comparisons are slippery things; but for the present let us assume the resemblance of the two, which may probably be disallowed hereafter. And so, from division comes purification; and from this, mental purification; and from mental purification, instruction; and from instruction, education; and from education, the nobly-descended art of Sophistry, which is engaged in the detection of conceit. I do not however think that we have yet found the Sophist, or that his will ultimately prove to be the desired art of education; but neither do I think that he can long escape me, for every way is blocked. Before we make the final assault, let us take breath, and reckon up the many forms which he has assumed: (1) he was the paid hunter of wealth and birth; (2) he was the trader in the goods of the soul; (3) he was the retailer of them; (4) he was the manufacturer of his own learned wares; (5) he was the disputant; and (6) he was the purger away of prejudices—although this latter point is admitted to be doubtful.
Now, there must surely be something wrong in the professor of any art having so many names and kinds of knowledge. Does not the very number of them imply that the nature of his art is not understood? And that we may not be involved in the misunderstanding, let us observe which of his characteristics is the most prominent. Above all things he is a disputant. He will dispute and teach others to dispute about things visible and invisible—about man, about the gods, about politics, about law, about wrestling, about all things. But can he know all things? “He cannot.” How then can he dispute satisfactorily with anyone who knows? “Impossible.” Then what is the trick of his art, and why does he receive money from his admirers? “Because he is believed by them to know all things.” You mean to say that he seems to have a knowledge of them? “Yes.”
Suppose a person were to say, not that he would dispute about all things, but that he would make all things, you and me, and all other creatures, the earth and the heavens and the gods, and would sell them all for a few pence—this would be a great jest; but not greater than if he said that he knew all things, and could teach them in a short time, and at a small cost. For all imitation is a jest, and the most graceful form of jest. Now the painter is a man who professes to make all things, and children, who see his pictures at a distance, sometimes take them for realities: and the Sophist pretends to know all things, and he, too, can deceive young men, who are still at a distance from the truth, not through their eyes, but through their ears, by the mummery of words, and induce them to believe him. But as they grow older, and come into contact with realities, they learn by experience the futility of his pretensions. The Sophist, then, has not real knowledge; he is only an imitator, or image-maker.
And now, having got him in a corner of the dialectical net, let us divide and subdivide until we catch him. Of image-making there are two kinds—the art of making likenesses, and the art of making appearances. The latter may be illustrated by sculpture and painting, which often use illusions, and alter the proportions of figures, in order to adapt their works to the eye. And the Sophist also uses illusions, and his imitations are apparent and not real. But how can anything be an appearance only? Here arises a difficulty which has always beset the subject of appearances. For the argument is asserting the existence of not-being. And this is what the great Parmenides was all his life denying in prose and also in verse. “You will never find,” he says, “that not-being is.” And the words prove themselves! Not-being cannot be attributed to any being; for how can any being be wholly abstracted from being? Again, in every predication there is an attribution of singular or plural. But number is the most real of all things, and cannot be attributed to not-being. Therefore not-being cannot be predicated or expressed; for how can we say “is,” “are not,” without number?
And now arises the greatest difficulty of all. If not-being is inconceivable, how can not-being be refuted? And am I not contradicting myself at this moment, in speaking either in the singular or the plural of that to which I deny both plurality and unity? You, Theaetetus, have the might of youth, and I conjure you to exert yourself, and, if you can, to find an expression for not-being which does not imply being and number. “But I cannot.” Then the Sophist must be left in his hole. We may call him an image-maker if we please, but he will only say, “And pray, what is an image?” And we shall reply, “A reflection in the water, or in a mirror”; and he will say, “Let us shut our eyes and open our minds; what is the common notion of all images?” “I should answer, Such another, made in the likeness of the true.” Real or not real? “Not real; at least, not in a true sense.” And the real “is,” and the not-real “is not”? “Yes.” Then a likeness is really unreal, and essentially not. Here is a pretty complication of being and not-being,
