there are other arts which persuade, such as arithmetic, which is an art of persuasion about odd and even numbers. Gorgias is made to see the necessity of a further limitation, and he now defines rhetoric as the art of persuading in the law courts, and in the assembly, about the just and unjust. But still there are two sorts of persuasion: one which gives knowledge, and another which gives belief without knowledge; and knowledge is always true, but belief may be either true or false,—there is therefore a further question: which of the two sorts of persuasion does rhetoric effect in courts of law and assemblies? Plainly that which gives belief and not that which gives knowledge; for no one can impart a real knowledge of such matters to a crowd of persons in a few minutes. And there is another point to be considered:—when the assembly meets to advise about walls or docks or military expeditions, the rhetorician is not taken into counsel, but the architect, or the general. How would Gorgias explain this phenomenon? All who intend to become disciples, of whom there are several in the company, and not Socrates only, are eagerly asking:—About what then will rhetoric teach us to persuade or advise the state? Gorgias illustrates the nature of rhetoric by adducing the example of Themistocles, who persuaded the Athenians to build their docks and walls, and of Pericles, whom Socrates himself has heard speaking about the middle wall of the Piraeus. He adds that he has exercised a similar power over the patients of his brother Herodicus. He could be chosen a physician by the assembly if he pleased, for no physician could compete with a rhetorician in popularity and influence. He could persuade the multitude of anything by the power of his rhetoric; not that the rhetorician ought to abuse this power any more than a boxer should abuse the art of self-defence. Rhetoric is a good thing, but, like all good things, may be unlawfully used. Neither is the teacher of the art to be deemed unjust because his pupils are unjust and make a bad use of the lessons which they have learned from him.