“When somebody persuades me I am wrong, I change my mind.”

“When the facts change, I change my mind - what do you do, sir?”

“But my lord, when we addressed this issue a few years ago, didn't you argue the other side?" He said, "That's true, but when I get more evidence I sometimes change my mind. What do you do?”

“When my information changes, I alter my conclusions. What do you do, sir?”

“I would rather be vaguely right than precisely wrong.”

“I find economics increasingly satisfactory, and I think I am rather good at it. I want to manage a railroad or organise a Trust or at least swindle the investing public”

“The ideas of economists and political philosophers, both when they are right and when they are wrong are more powerful than is commonly understood. Indeed, the world is ruled by little else. Practical men, who believe themselves to be quite exempt from any intellectual influences, are usually slaves of some defunct economist.”