Knowledge

"When you know a thing, to hold that you know it; and when you do not know a thing, to allow that you do not know it - this is knowledge."
-Confucius (551 BC - 479 BC), The Confucian Analects

"There is only one good, knowledge, and one evil, ignorance."
-Socrates (469 BC - 399 BC), from Diogenes Laertius, Lives of Eminent Philosophers

"Knowledge is of two kinds. We know a subject ourselves, or we know where we can find information on it."
-Samuel Johnson (1709 - 1784), quoted in Boswell's Life of Johnson

"Only knowledge that is used sticks in your mind."
-Dale Carnegie