Out of your own mouth, Socrates, you are convicted, he said.

Well, but, Euthydemus, I said, has that never happened to you? for if I am
only in the same case with you and our beloved Dionysodorus, I cannot
complain. Tell me, then, you two, do you not know some things, and not
know others?

Certainly not, Socrates, said Dionysodorus.

What do you mean, I said; do you know nothing?

Nay, he replied, we do know something.

Then, I said, you know all things, if you know anything?

Yes, all things, he said; and that is as true of you as of us.

O, indeed, I said, what a wonderful thing, and what a great blessing! And
do all other men know all things or nothing?

Certainly, he replied; they cannot know some things, and not know others,
and be at the same time knowing and not knowing.

Then what is the inference? I said.

They all know all things, he replied, if they know one thing.

O heavens, Dionysodorus, I said, I see now that you are in earnest; hardly
have I got you to that point. And do you really and truly know all things,
including carpentering and leather-cutting?