Donald Rumsfeld

“There are known knowns; there are things we know we know. We also know there are known unknowns; that is to say we know there are some things we do not know. But there are also unknown unknowns – the ones we don't know we don't know.”

“You go to war with the Army you have, not the Army you might want or wish to have at a later time.”

“The absence of evidence is not evidence of absence.”

“Freedom's untidy, and free people are free to make mistakes and commit crimes and do bad things.”

“I don't do quagmires.”

“It is easier to get into something than to get out of it.”

“Simply because you do not have evidence that something does exist does not mean that you have evidence that it doesn't exist.”

“Don't necessarily avoid sharp edges. Occasionally they are necessary to leadership.”

“The way to win is to, every time, be honest and straightforward and say, 'We don't know.'”

“I would not say that the future is necessarily less predictable than the past. I think the past was not predictable when it started.”

“Learn to say 'I don't know.' If used when appropriate, it will be often.”

“I believe what I said yesterday. I don't know what I said, but I know what I think, and, well, I assume it's what I said.”

“If you are not being criticized, you may not be doing much.”

“The Department of Defense, where I have spent some of the best years of my life, is a remarkable institution.”