“If you put into one room everyone who considered themselves a Nietzschean, there would be a bloodbath.”

To disarm while being best armed, out of an elevation of sensibility-that is the means to real peace.

Deception is a sort of seduction. In love and war, adultery and espionage, deceit can only succeed if the deceived party is willing, in some way, to be deceived.

Libraries are not just for reading in, but for sociable thinking, exploring, exchanging ideas and falling in love. They were never silent.

I love telling stories, and am almost entirely unable to keep a secret.

What if?’ history is a tricky game, but there is no doubt that the senior planners of D-Day – including Eisenhower and the British general Bernard Montgomery – believed that the Double Cross operation had played a pivotal role in the victory.

Technology will not change that, for even in the starchiest heyday of Victorian self-improvement, libraries were intended to be meeting places of the mind, recreational as well as educational.

The broad outlines of the Double Cross deception have been known since 1972, when Sir John Masterman, the former chairman of the double agent committee, controversially published his account of the operation in defiance of official secrecy.