one of the two alternatives is necessary, it will then be necessary either that Hermachus should be alive to-morrow, or not. But there is no such necessity in the nature of things. Let the dialecticians then, that is to say, Antiochus and the Stoics, contend with him, for he upsets the whole science of dialectics.
For if a disjunctive proposition made up of contraries, (I call those propositions contraries when one affirms and the other denies,) if, I say, such a disjunctive can be false, then no one is ever true. But what quarrel have they with me who am following their system? When anything of that kind happened, Carneades used to joke in this way:—“If I have drawn my conclusion correctly, I gain the cause: if incorrectly, Diogenes shall pay back a mina;” for he had learnt dialectics of that Stoic, and a mina was the pay of the dialecticians.
I, therefore, follow that system which I learnt from Antiochus; and I find no reason why I should judge “If it does shine, it does shine” to be true, because I have learnt that everything which is connected with itself is true; and yet not judge “If you lie, you lie,” to be connected with itself in the same manner. Either, therefore, I must judge both this and that to be true, or, if I may not judge this to be true, then I cannot judge that to be.
XXXI. However, to pass over all those prickles, and all that tortuous kind of discussion, and to show what we are:—after having explained the whole theory of Carneades, all the quibbles of Antiochus will necessarily fall to pieces. Nor will I say anything in such a way as to lead any one to suspect that anything is invented by me. I will take what I say from Clitomachus, who was with Carneades till his old age, a man of great shrewdness, (indeed, he was a Carthaginian,) and very studious and diligent. And he has written four books on the subject of withholding assent; but what I am going to say is taken out of the first.
Carneades asserts that there are two kinds of appearances; and that the first kind may be divided into those which can be perceived and those which cannot; and the other into those which are probable and those which are not. Therefore, those which are pronounced to be contrary to the senses and contrary to evidentness belong to the former division;
