Certainly there is, he replied; there can be no question of that. Do you, Dionysodorus, maintain that there is not?
You will never prove to me, he said, that you have heard any one contradicting any one else.
Indeed, said Ctesippus; then now you may hear me contradicting Dionysodorus.
Are you prepared to make that good?
Certainly, he said.
Well, have not all things words expressive of them?
Yes.
Of their existence or of their non-existence?
Of their existence.
Yes, Ctesippus, and we just now proved, as you may remember, that no man could affirm a negative; for no one could affirm that which is not.