KNOWLEDGE AND HALF-KNOWLEDGE
Four frogs sat upon a log that lay floating on the edge of a river. Suddenly the log was caught by the current and swept slowly down the stream. The frogs were delighted and absorbed, for never before had they sailed.
At length the first frog spoke, and said, "This is indeed a most marvellous log. It moves as if alive. No such log was ever known before."
Then the second frog spoke, and said, "Nay, my friend, the log is like other logs, and does not move. It is the river, that is walking to the sea, and carries us and the log with it."
And the third frog spoke, and said, "It