"Certainly; I must agree to that."

"Then you can distinguish between something you know and something you do not know?"

"Yes."

"Consider a moment, Socrates. Is it possible for you to know the difference between one thing and another unless you know both things?"

"Why, no! I must admit that," said Socrates.

"Then mark where I lead you; for if you know the things you know, you must also know the things you do not know."

Every one was now laughing immoderately; not only at Philip's dialectic, but at his pompous gestures, wherewith he mimicked many well-known sophists; blowing out his cheeks, pursing his lips, tapping his head suspiciously, and rubbing his nose.

"By the dog of Egypt!" cried Socrates; "the man has been with Euthydemus."

"Euthydemus is a child to me," said Philip contemptuously.

"But, Philip, if I confess I know nothing?" said Socrates, when the laughter failed a little.