Against him, who said, Give not thy judgment till both sides are heard, Zeno on the contrary made use of such an argument as this: If he who spake first has plainly proved his cause, the second is not to be heard, for the question is at an end; and if he has not proved it, it is the same case as if being cited he did not appear, or appearing did nothing but wrangle; so that, whether he has proved or not proved his cause, the second is not to be heard. And yet he who made this dilemma has written against Plato’s Commonweal, dissolved sophisms, and exhorted his scholars to learn logic, as enabling them to do the same. Now Plato has either proved or not proved those things which he writ in his Commonweal; but in neither case was it necessary to write against him, but wholly superfluous and vain. The same may be said concerning sophisms.