Most people know at least two things about the eminent historian Eric Hobsbawm. First, that he is, or was, a Marxist who believed in communist world revolution for his entire adult life. Second, that the 90-year-old has become as he disarmingly put it himself, "an accepted member of the official British cultural establishment", and something of a national teddy bear.
Though born abroad, Hobsbawm has always been an essentially middle-class British figure. He completed his secondary education here and went up to Cambridge as an undergraduate. He has worked hard to cultivate an ironical detachment from Britain and its traditions which comes easily only to those who truly belong.
All this distinguishes him from erstwhile comrades, such as Chinese peasants, Ukrainian Jews, Afghan women and South Africans of all colours. It is no surprise that they should have joined, persevered with and often died for the Communist Party. Unlike many in the past century of "extremes", however, Hobsbawm had a choice and he chose tyranny.
It was in Berlin, where he spent his adolescence, as Hobsbawm put it in his autobiographical Interesting Times , that he became "a lifelong communist, or at least a man whose life would lose its nature and its significance without the political project" of the October Revolution.
Surveying the political scene shortly before the Nazi takeover of power, Hobsbawm claimed that "for someone like myself there was really only one choice", if Hitler was to be stopped. In fact, there was an alternative open to Hobsbawm: he could have backed the German or Austrian Social Democrats, whose record of resistance against the Nazis was to be more distinguished, and certainly more consistent. Not for the first or last time, Hobsbawm's historical judgment is clouded by ideological blinkers.
After all, communists were required to show total commitment to the "party line" as laid down, ultimately, by Moscow. "The Party", Hobsbawm writes, "had the first, or more precisely, the only real claim on our lives...whatever it had ordered, we would have obeyed". Among the "party lines" which Hobsbawm had to swallow were the definition of the German Social Democrats as "social fascists", the Great Purges of the 1930s, the Nazi-Soviet pact of 1939, and the show trials of the late Stalinist era, many of them with distinct anti-Semitic undertones.
And while he was seriously disturbed by the suppression of the Hungarian uprising in 1956, Hobsbawm did not join the general exodus from the party.
None of this, of course, disqualifies Hobsbawm as an historian. Even today, such innovative works as Primitive Rebels , Labouring Men  and Bandits  can still be read with profit. When they appeared, they were rightly regarded as sensational. Likewise, his three volumes on 19th-century European history, The Age of Revolution, 1789-1848 , The Age of Capital, 1848-1875  and The Age of Empire 1875-1914  have all achieved the status of classics. These were, by their nature, not works of original research. Where Hobsbawm broke new ground was in his ideas, the inspired hunches which showed us how to look at familiar phenomena in new ways. For example, in The Invention of Tradition (which he co-edited with Terence Ranger), he demonstrated how many "timeless" British traditions were actually recent 19th-century inventions.
It is in his study of the 20th century, to which much of his oeuvre is devoted, that the cloven hoof becomes apparent. The heterodoxy of the earlier work gives way to ideologically conformist sleight of hand. In The Age of Extremes , for example, he glosses the Soviet attack on Finland in 1939-1940 with the remark that it "pushed the Russian frontiers a little further away from Leningrad", parroting contemporary communist propaganda that Stalin's unprovoked aggression had actually been some form of self-defence.
He describes the suppression of the Warsaw rising in 1944, as "the penalty of premature risings", without mentioning that Stalin deliberately left the bourgeois Polish Home Army to its fate. Later on, he suggests that the great achievement of the Russian Revolution was to frighten Western capitalists into reform, completely neglecting the fact that more humane alternatives had been available long before the murderous utopianism of the communists appeared on the scene.
Despite or perhaps because of all this, the collapse of the Soviet Union did not much cramp Hobsbawm's style in The Age of the Extremes.
Hiding behind the death-bed words of the Polish socialist economist Oskar Lange, he once again denied that there was any alternative to the murderous brutalities of the Soviet system: "I wish I could say there was, but I cannot."
For Hobsbawm to have written anything else, of course, would have been to admit that the most persistently dangerous "extreme" of the 20th century had been his own.