“There are known knowns, things we know that we know; and there are known unknowns, things that we know we don't know. But there are also unknown unknowns, things we do not know we don't know.”

“There are known knowns, things we know that we know; and there are known unknowns, things that we know we don't know. But there are also unknown unknowns, things we do not know we don't know.”

“You’re seeing someone else, aren’t you?" Seeing someone else? How on earth could that explain any of this? Why would seeing someone else necessitate bringing home a middle­-aged woman, a teenaged punk and an American with a leather jacket and a Rod Stewart haircut? What would the story have been? But then, after reflection, I realised that Penny had probably been here before, and therefore knew that infidelity can usually provide the answer to any domestic mystery. If I had walked in with Sheena Easton and Donald Rumsfeld, Penny would probably have scratched her head for a few seconds before saying exactly the same thing. In other circumstances, on other evenings, it would have been the right conclusion, too; I used to be pretty resourceful when I was being unfaithful to Cindy, even if I do say so myself. I once drove a new BMW into a wall, simply because I needed to explain a four­-hour delay in getting home from work. Cindy came out into the street to inspect the crumpled bonnet, looked at me, and said, “You’re seeing someone else, aren’t you?” I denied it, of course. But then, anything – smashing up a new car, persuading Donald Rumsfeld to come to an Islington flat in the early hours of New Year’s Day – is easier than actually telling the truth. That look you get, the look which lets you see right through the eyes and down into the place where she keeps all the hurt and the rage and the loathing... Who wouldn’t go that extra yard to avoid it?”

“Be yourself. Follow your instincts. Success depends, at least in part, on the ability to 'carry it off.'”

“In our system leadership is by consent, not command. To lead a President must persuade. Personal contacts and experiences help shape his thinking. They can be critical to his persuasiveness and thus to his leadership.”

“Presidential leadership needn't always cost money. Look for low- and no-cost options. They can be surprisingly effective.”

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

“If in doubt, don't. If still in doubt, do what's right.”

“If it were a fact, it wouldn't be called intelligence.”

“Reports that say that something hasn't happened are always interesting to me, because as we know, 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.”

“Donald Rumsfeld. Love him or hate him, you've gotta admit: a lot of people hate him.”

“And for once, Donald Rumsfeld, in the news at the time over the Iraq war made sense to me: "As we know," he said, famously, "there are known knowns-things we know we know. We also know there are known unknowns-things we know we don't know. But there are also unknown unknowns- things we don't know we don't know.”