What kind of person - not American but British, with a degree in history, not art - gets invited to become the New Yorker's art critic?
What kind of person becomes one of Cambridge University's youngest ever lecturers and follows that with an Oxford fellowship and a chair at Harvard? Oh, and writes and broadcasts prodigiously, magisterially and entertainingly on a range of subjects encompassing culture, politics, mythology, Americans, British, Dutch, French - and Jews?
Each of these questions can be answered by citing the one of a kind that is Simon Schama. Briefly back in London from his home across the Atlantic (his wife is an American professor of genetics and they have a daughter, son and grandson), he is lending his considerable assent to the National Gallery's "stupendous" exhibition of Rembrandt's late paintings preceding his death in 1669.
Schama's passion for the pictures - "masterpiece after masterpiece" - is palpable. For example, standing before The Jewish Bride, as he was at the close of BBC2's Schama on Rembrandt last Saturday night, proclaiming, "this is the painting of love", Schama is a bridge of enthusiasm between canvas and viewer.
This is not on account of any sentimental affinity with the heimishe-sounding subject. Over breakfast in a west London café so upmarket that a man at a nearby table calls for bottled water to clean away some spilt coffee, Schama assures me that Rembrandt's "Jewish" bride is extremely unlikely to be Jewish.
The work was "formerly just known as a painting of a young couple", says Schama - whose dazzlingly detailed book, Rembrandt's Eyes, is being republished to coincide with the National Gallery show - "but such was the popularity of 'Rembrandt loves the Jews and the Jews love Rembrandt' in the 19th century that they called it The Jewish Bride, and its value shot up."
It seems that German-Jewish art historians were particularly prominent advocates of the belief that a vast number of the portraits Rembrandt painted were of Jews whom he lived alongside on Amsterdam's Breestraat. "It's extraordinary," says Schama, "how German writing went from describing what they saw as Rembrandt's romance with the Jews - automatically assuming any old geezer with a beard, or possibly a skullcap, to be a Jew even though Christians wore skullcaps, too - to the Nazis' aryanisation of Rembrandt." This culminated in 1944 with a "Rembrandt Day" in occupied Holland.
Rembrandt would certainly have used local Jews as models for his great biblical and other works. "The whole world was his cast of characters," Schama says. "His house is stuffed full of Japanese armour and South American musical instruments. He glories in the exoticism of Amsterdam - the first great cosmopolitan metropolis in Europe after ancient Rome. His paintings are of Africans, Muscovites, Poles. He can't get enough of the rich variety of human comedy."
So, how did the young Cambridge history scholar blossom into a leading authority on art? Well, Schama was never a kings-and-dates sort of historian. He has always been interested in the full cultural span. He describes his early book, The Embarrassment of Riches: An Interpretation of Dutch Culture in the Golden Age, as a "cultural anthropology of people who lived their lives surrounded by visual images - on their cups, glasses, tiles and in their language. The book was an attempt to integrate images into the text, not just as illustrations.
"There's a great essay by Erwin Panofsky, which changed my life. In it, he talks about the indispensability of understanding the way a culture operates in order to appreciate the art. But, equally, if you're trying to do a cultural history, make the imagery as indispensable as documents. So, for me, he was responsible for unpicking the already frayed boundary between history and art history."
And how about cultural journalism? Schama recalls feeling intimidated when taken on by Tina Brown, who edited the New Yorker in the 1990s, but he was nothing if not determined to jump in at the deep end.
"I had done quite a lot of reviewing. It was John Gross who first got me to review art when he started to run non-book reviews in the TLS. Still, the New Yorker was an incredible test. I was stepping into the shoes of many mighty figures, but it's not the kind of job you turn down. Tina said, 'start with a really long piece' and I thought I'd do the hardest one I could think of - a huge, fantastic Mondrian show… hardcore modernist, abstract painter, totally not someone from the 17th or 18th century. And it worked."
When I ask Schama how he holds together in his mind the big picture and the precise detail, his instant reply is "coffee" (by now he is finishing his second cup).
But the 69-year-old admits it is an increasingly challenging task. "As you get older you do have a trees-and-forest thing.
"You want to embed your non-academic reader in a set of characters and a set of stories without losing the point of them being there. They're not there as a kind of stroll down memory lane."
This was especially a problem, he says, with last year's five-part BBC2 series and ongoing book, The Story of the Jews.
"I wanted a large, non-Jewish audience to come into and be surrounded by a much bigger story than the Holocaust and the Israeli-Palestinian conflict, and say to them, 'this is your story as much as it's mine'."
Which leads us into a conversation about Jewish identity (his is "Spinoza-ist") and Zionism.
"The moral case for Zionism is made not just by what the Nazis did - or everybody else failed to do," he says. "It was the refuge of last resort in the place in which our identity was born and which, in terms of our cultural identity, we never left. People who think we were just European imperialists who marched in on the shoulders of the Balfour Declaration, know nothing about Yehuda Halevi [nearly 900 years ago], 16th-century Safed, and the great attempts to found a Jewish community in 1700. And they know nothing about the continuity of a Jewish presence in Palestine."
In wider politics, he is well known as a great Barack Obama fan but as the US President nears the end of his term, Schama confesses to a slight feeling of disappointment.
"I think he gets too little credit for saving the American and, by extension, the world economy. But he doesn't have the vulgar taste for power. You want some of that in a president. Roosevelt had it in cartloads. Lyndon Johnson had it. God knows, Bill Clinton had it. They were successful Democratic presidents. Obama is too much the philosopher, not enough the king."
And where did the glittering Schama CV begin? Intriguingly, with a job in the JC library as a teenager.
"I was in love with the editor's daughter and went with her to do little music reviews. I knew nothing about classical music and just copied the kinds of adjectives the critics used, like 'lyric', 'tender', 'exhilarating'. I got away with it."
Many adjectives later, Schama's communicative powers are untarnished by such subterfuge.
