That held true for Berlin’s response to all those Jews he came across. He was perfectly happy to divide their number into “good Jews” and “bad Jews”. He was equally content — the example of Meyer Schapiro springs to mind — to delight in someone “as a Jew”. This ineradicable sense, both of attachment and difference, was similarly if oppositely true of his lifelong reaction to exile among the gentiles. Expelled from his first homeland, Berlin was a dedicated Anglophile. He never came to think of himself as an ordinary Englishman. By the same token, he took it as axiomatic that “even the most friendly, unbiased, unprejudiced Englishman today [1985] does not think of Jews as English”. This was not because he regarded England as an anti-Semitic country. These he identified as “Russia, Germany, Poland, France and the United States”.

This was important in and of itself. It also pointed to one of the reasons why Berlin accepted, from the very first, Herzl’s insistence that the great 19th-century European project for Jewish assimilation, that is, emancipation as assimilation, had failed. Perhaps it was bound to.In these circumstances, self-respect as much as self-preservation demanded a positive response. There lay the basis for Berlin’s one, lifelong, unwavering, concrete political commitment. This was to Zionism. Berlin was rarely accused of reckless moral courage during the course of his life. Yet he was unerring in his dedication to the cause of Israel, even in the face of so many developments in that country which subsequently disturbed him. This stance stands as critical testimony against those who suggest that in all substantial things he was never more than a “trimmer”.

It is surely anything but fanciful to see in that, essential, definition and in those, particular, commitments, the grounds of his broader political teachings. Berlin devoted the greater part of his scholarly life to exploring Romanticism’s critique of the Enlightenment. He was often — wrongly — reckoned to subscribe to that criticism himself. When so challenged, he justly pointed to what he had said long before: “The intellectual power, honesty, lucidity, courage and disinterested love of the truth of those most gifted thinkers of the eighteenth century remains to this day without parallel. Their age was one of the best and most hopeful episodes in the history of mankind.”

However, Berlin also instinctively understood the limits of Enlightenment. To the extent that the Enlightenment project criticised—better still, exposed—pretentious theocracy, unproblematised tradition and simply superstition, it was both true and liberating. Herzen taught him that. But to the degree that it also demanded a cosmopolitan politics, nothing short of a universal reordering of regimes, it failed to comprehend, and in that way also failed to assuage, the most basic and unyielding demands of mankind. Herder furnished this insight.

History taught something more. This was that there was much to be said for a certain, limited but real, “oscillation” between these two traditions. Failure to sustain that balance led to the temptation of monism — the assertion of a universally applicable and harmonious rule and from there to the real nightmares of “totalitarianism” — the application of precisely that intellectual fantasy on all too messy a reality. For Berlin, the history of the 20th century was plagued by examples of this characteristically modern mistake. The Soviet Union was no more (nor less) than the most terrifying case of this error.