What is remarkable is that Kissinger did all this, and yet remained likeable. His humour, always close to the surface, occasionally bubbled over it: “To be absolutely certain about something, one must know everything or nothing about it.” “The history of things which didn’t happen has never been longer.” “Power is the great aphrodisiac.” I met Kissinger only occasionally but what I liked about him was that, at these meetings, however brief, he always told me something I didn’t know, and was well worth knowing. No other public figure I met had to the same degree this pleasing characteristic. And always, one felt, his ultimate aspirations were on higher things. He was often compared to Machiavelli. Few characters in history he despised more. He wrote extensively on Metternich and Bismarck, making it clear he had a low opinion of both. The man he most admired and tried to follow was Kant. At heart and in his inmost thoughts, Kissinger was an idealist, working for the perpetual peace of which Kant wrote, using the imperfect means of an imperfect world. He enjoyed — still enjoys — life, and sees its funny side, especially the way in which his power brought him access to women. In short, behind the colossal intellect, the huge output of ideas, and the prodigies of diplomacy and theorising, Doctor Kissinger was fun to know. I liked him and valued him and am glad Niall Ferguson is giving him the meticulous scrutiny he deserves.