“You can change only what people know, not what they do.”

Source: His Dark Materials, The Golden Compass (1995), Ch. 18 : Fog and Ice

Source: The Portrait of a Lady (1881), Ch. XXII.

Source: Skulduggery Pleasant

Source: Culture series, Inversions (1998), Chapter 4 (p. 69)

Quoted in Eleanor Harris, The Real Story of Lucille Ball, ch. 1 (1954)

Comments to Prof. David F. Boyd at the Louisiana State Seminary (24 December 1860), as quoted in The Civil War : A Book of Quotations (2004) by Robert Blaisdell. Also quoted in The Civil War: A Narrative (1986) by Shelby Foote, p. 58.
1860s, 1860
Context: You people of the South don't know what you are doing. This country will be drenched in blood, and God only knows how it will end. It is all folly, madness, a crime against civilization! You people speak so lightly of war; you don't know what you're talking about. War is a terrible thing! You mistake, too, the people of the North. They are a peaceable people but an earnest people, and they will fight, too. They are not going to let this country be destroyed without a mighty effort to save it … Besides, where are your men and appliances of war to contend against them? The North can make a steam engine, locomotive, or railway car; hardly a yard of cloth or pair of shoes can you make. You are rushing into war with one of the most powerful, ingeniously mechanical, and determined people on Earth — right at your doors. You are bound to fail. Only in your spirit and determination are you prepared for war. In all else you are totally unprepared, with a bad cause to start with. At first you will make headway, but as your limited resources begin to fail, shut out from the markets of Europe as you will be, your cause will begin to wane. If your people will but stop and think, they must see in the end that you will surely fail.

Source: The Wars

The Fourth Way (1958)