The scene is the common room of All Souls College, Oxford, in the first week of March 1963. It is the idle half-hour after lunch when fellows slump into armchairs and gaze out of the window at the sparrows in the Fellows’ Garden. David Caute, a young first-class mind in his mid-twenties, is buttonholed by the revered figure of Sir Isaiah Berlin. What did Caute think of Isaac Deustcher? Did he admire him, as so many young scholars on the left did? Well, Caute replied cautiously, he knew Deutscher’s book on Stalin and his trilogy on Trotsky.  ‘Quite sufficient.’ And Berlin bounded off into one of his rapid-fire bombardments: there were Marxist historians such as Eric Hobsbawm and E.H.Carr whom Berlin liked and even admired, though he completely disagreed with them. But Deutscher was different; he was a liar, a distorter; he twisted the truth to make Trotsky look like Jesus on the Cross. Berlin would not dine at the same table with the man. Deutscher had to be stopped.

From this unnerving tirade, the young Caute gathered only that Berlin would do anything he could to prevent Deutscher from corrupting the minds of the young. And indeed he already had. When Deutscher had applied for a job as senior lecturer at Sussex University, Asa Briggs and the other professors in the department had jumped at the prospect and proposed to offer him a professorship in Soviet Studies. Isaiah Berlin was an external adviser to the board and the natural person for the vice-chancellor, John Fulton, to consult. Would Deutscher be suitable? No, Berlin replied on 4 March 1963, Deustcher would not: ‘The candidate of whom you speak is the only man whose presence in the same academic community as myself I should find morally intolerable.’ Coming from a man of Berlin’s eminence, that put the kybosh on Deutscher’s chances. He died four years later, never having held an academic post. When Berlin burst into the All Souls common room, he had either just put the knife in, or was on the point of doing so.

This disagreeable little incident may seem like a slender foundation for a sizable book 50 years later. One is tempted to repeat the wisecrack attributed to Henry Kissinger (though there are other claimants, going as far back as Woodrow Wilson) that ‘academic politics are so vicious precisely because the stakes are so small’.

But Caute is really writing about something larger and more fascinating. I cannot quite agree, as the blurb claims, that the book ‘brings to life for the first time the full severity of Berlin’s action against Deustcher’. The correspondence was published in Tariq Ali’s journal Black Dwarf back in 1969, and the history of the affair was summarised in Michael Ignatieff’s biography of Berlin in 1998. But what Caute does do, rather ingeniously, is to deploy the Berlin-Deutscher spat to deconstruct the attitudes of the intelligentsia to the Cold War during its years of maximum intensity — a demolition job he first embarked on 40 years ago in his marvellous book The Fellow Travellers. There, Deutscher had barely a walk-on part. He was, after all, rather more than a fellow traveller on the great red train. He was right up in the driver’s cab, helping to shovel in more coal.

In Isaac & Isaiah, Deutscher certainly gets a well-deserved pasting. Caute shows in abundant detail that he was guilty as charged, of callous and cynical gulag denial. But the book’s real thrust is its sustained and somewhat feline attack on the reputation of Berlin. He is portrayed here as something of a social butterfly, deplorably at home in the salons of London, New York and Washington, more famous for his talk than for his scholarly work (an accusation he was fully aware of and unhappy about). Berlin, we are told, failed to speak out on the great political issues of the day. When he was prodded to offer a view, he either equivocated or changed his mind when the operation began to go wrong, over Suez and Vietnam for example. In his only consistent public stance, his support for Israel, he doesn’t seem to have paid much attention to the plight of the Arabs.

As for his famous Two Concepts of Liberty, his distinction between negative liberty (not being bossed about, silenced or locked up) and positive liberty (access to food, health and work) is a phoney one. How can you be said to be free if you don’t have enough to eat, or a roof over your head? Under the guise of being a liberal independent spirit, Berlin was really only reinforcing the comfort and complacency of the rich and powerful. In any crunch, he always came down on the conservative side. And his persecution of Isaac Deutscher, whom he scarcely knew, does not look like the action of a defender of the free-speech sort of liberty.

For this onslaught, Caute marshals the combined cadet force of the high left: Perry Anderson, C.B. Macpherson, Charles Taylor. And on first inspection, the attack seems to be doing a fair bit of damage. Yet in the final analysis, I find most of it less than compelling.

To start with Deutscher, does there not come some point at which you ought to block the appointment of a scholar whom you regard as dishonest, especially for his shameless prettifying of the record of a ghastly tyrant? This, after all, is the argument put by those who would deny a platform to Dr David Irving. It seems to me that Berlin was entirely entitled, if not obligated, to veto Deutscher at Sussex. He is more open to criticism for his later efforts to pretend that he had not done so, in order not to upset Deutscher’s widow, Tamara. But reluctance to give offence is not exactly a deadly sin.

Then is it really the duty of an academic to make kneejerk public pronouncements on every  issue of the day? Caute’s own brilliant research over decades demonstrates how academics are liable to be even more blinded by prejudice than the rest of us, to have less knowledge or understanding of the outside world, and to go on backing evil regimes long after everyone else has seen through them.

In terms of political ideas, the insistence that ‘freedom’ ought to include everything desirable in life has, time and again, led to the most brutish suppressions of freedom in the ordinary sense. Millions have been butchered in the name of that fuller freedom. I persist in regarding Berlin’s famous footnote in Two Concepts of Liberty as the beginning of political wisdom (to be fair, Caute does quote the footnote):

To avoid glaring inequality or widespread misery I am ready to sacrifice some, or all of my freedom, but it is freedom that I am giving up. Everything is what it is: liberty is liberty, not equality or fairness or justice or human happiness or a quiet conscience.

Nor is it true that, when Berlin died, he was reviled by the New Left but adored by everyone else. On the contrary, robust conservatives such Roger Scruton and Paul Johnson despised him for precisely the same sin: that he refused to stand up for his beliefs. The hard men of both sides were united in their refusal to contemplate Berlin’s last lesson: that the things we want don’t necessarily gel with one another. Our ideals and principles may be incompatible. In real-life politics, trading off is the name of the game.

And it is not even true that Berlin’s indignation was reserved for his enemies on the left. I hope readers will forgive my recalling once again a personal encounter with Berlin which presents an eerie parallel to Caute’s ordeal in the All Souls common room. I had just written an enthusiastic article somewhere about the conservative philosopher Michael Oakeshott, and I was queuing at the issue desk in the London Library, when Berlin buttonholed me, almost shaking with urgency and annoyance: ‘You were far too kind to Oakeshott, far too kind, the man’s a complete fraud, he has no doctrine at all, nothing resembling a doctrine, he has nothing to say.’  This outburst was all the more remarkable, since what Berlin  and Oakeshott had in common, it seemed to me, was that they passionately rejected the idea that a single doctrine could provide all the answers. What they both taught was that the world is a complicated place. And indeed their unexpected antipathy, which was mutual, showed just how true that is.

As a picture of the intellectual life of half a century, Isaac & Isaiah is a beguiling guide, superbly written and never less than absorbing. But I do not expect that it will change many minds, one way or the other.