“And death shall have no dominion,” Dylan Thomas wrote in one of his better poems. It has certainly had little sway over the careers of two of Oxford’s finest minds. Isaiah Berlin, the political philosopher, died in 1997, aged 88; Hugh Trevor-Roper, the historian, died in 2003, aged 89. But in death both men have been more prolific than when they were alive.

Berlin has published four new books on the history of ideas, “The Roots of Romanticism”, “Three Critics of the Enlightenment”, “Freedom and its Betrayal” and “Political Ideas in the Romantic Age”. He has also produced a study of Soviet Communism, “The Soviet Mind”, and two thick volumes of letters, with two more still to come. Several of his classic essays have been republished, some in expanded form, and there is still more unpublished material in the Isaiah Berlin Virtual Library (berlin.wolf.ox.ac.uk).

Trevor-Roper has produced a magnificent monograph on a Renaissance doctor, “Europe’s Physician: The Various Life of Sir Theodore De Mayerne”. “Great history books are few and far between,” the Times Literary Supplement wrote. “This is one.” He has also published a delightfully subversive book on Scottish nationalism, “The Invention of Scotland”; a formidable collection of essays, “History and the Enlightenment”; a volume of letters to the art historian Bernard Berenson; and his wartime journals. And there is more to come: a volume on Britain’s Secret Intelligence Services during the war (which will include his short book on Kim Philby), a volume on Nazi Germany, and, if all goes well, a collection of letters to such luminaries as Noel Annan, the leading historian of the British intelligentsia, and Alan Clark, the gloriously badly behaved Tory politician.

We owe this windfall to wonderful work by the two men’s friends and pupils—notably Henry Hardy, Berlin’s indefatigable amanuensis, and Blair Worden, Trevor-Roper’s literary executor. But the windfall raises deeper questions. Why do Berlin and Trevor-Roper command eager audiences among people who never met them? Why did they leave so much of their best work unpublished? And what does the cult of these antique figures—one born in 1909, the other in 1914—tell us about the relative merits of the academic world that they adorned and the one we have inherited? For it is hard to think of any modern academics who will command such attention after their deaths—or leave such a treasure trove behind them.

Trevor-Roper and Berlin were not bosom buddies. Berlin spent much of his career at All Souls, Oxford’s most gilded cage, where I had the privilege of getting to know him as a young prize fellow; Trevor-Roper loathed All Souls because it had (foolishly) rejected him for a prize fellowship, the only snub in an otherwise pluperfect undergraduate career. They had very different temperaments. Berlin was a people-pleaser. Trevor-Roper could be aloof—“a robot, without human experience, with no girls, no real friends, no capacity for intimacy and no desire to like or be liked” in Maurice Bowra’s phrase. This was unkind: he could be generous to the oddest of people and, like any good Christ Church man, he delighted in the sound of broken glass. Richard Davenport-Hines gets closer to the bone when he describes him as “a gregarious introvert”.

Berlin was one of the great talkers of his age. As a young man in the 1930s he often started a conversation with J.L. Austin, his fellow philosopher, over breakfast in All Souls and continued until lunch. Trevor-Roper preferred the solitude of the study and the discipline of the pen (“the beauty of conversation”, he confided to his journals, “consists of the mute, attentive faces of one’s fellow talkers”). Still they were on friendly terms, belonged to the same charmed world of Oxford colleges, country houses and smart London salons, wrote for the same periodicals, supped with the same BBC producers, and shared a passion for poking fun at pedants, bores and second-raters.

Both men lived remarkable lives: remarkable enough to justify a pair of biographies, Michael Ignatieff’s “Isaiah Berlin: a Life” (1999) and Adam Sisman’s “Hugh Trevor-Roper” (2010; American title “An Honourable Englishman”). Berlin was brought up in Riga, in Russian-controlled Latvia, and St Petersburg, or Petrograd as it then was, witnessing both the Social Democratic and the Bolshevik revolutions before fleeing the latter’s horrific consequences. He worked at the British Embassy in Washington during the war, in charge of monitoring the changing political winds in Britain’s most important ally, and at the embassy in Moscow immediately thereafter, meeting Anna Akhmatova (who wrote a poem about him) and Boris Pasternak (who gave him a copy of “Doctor Zhivago” to smuggle out of the country).

Trevor-Roper worked for the Secret Intelligence Service in the war. He teamed up with a group of brilliant Oxford friends, including the philosophers Gilbert Ryle and Stuart Hampshire, succeeded in cracking the radio codes of Hitler’s secret service, the Abwehr, and, much to the fury of the old guard, rose up the ranks, ending up as a major. A three-bottle lunch with Dick White, the head of British intelligence in Berlin, led to one of his greatest works. The Soviets had circulated the rumour that Hitler had escaped from his bunker and was living in the West. White suggested that Trevor-Roper use his forensic skills to prove beyond doubt that Hitler had died in his bunker. The resulting book, “The Last Days of Hitler”, turned Trevor-Roper into a celebrity and kept him in funds. “An infinite, endless, golden shower of American dollars flows ceaselessly into my pockets,” he wrote at the time.

Both men were at the heart of the British establishment. Berlin’s honours included a knighthood, the order of merit (limited to 24 people at a time), and the presidency of the British Academy; he was a director of the Royal Opera and a trustee of the National Gallery. Trevor-Roper was the regius professor of modern history at Oxford and, thanks to Margaret Thatcher, sat in the House of Lords as Lord Dacre of Glanton, thereby gaining a second unwieldy name. He spent an unhappy period as master of Peterhouse, Cambridge, fighting a nest of Tory reactionaries who offended his Whiggish commitment to ordered progress.

Both men embodied a certain idea of Englishness. Trevor-Roper married the daughter of Field Marshal Haig, the British commander in the first world war. He drove a Bentley, hunted to hounds and spent the advance of his first book, “Archbishop Laud”, on a horse called Rubberneck. Berlin loved England—“the best country in the world”, he was fond of saying—and would have relished William Waldegrave’s description of him, at his memorial service, as the perfect embodiment of the English gentleman. Yet neither man was an establishment clone.

Berlin saw himself as a Russian and a Jew as well as an Englishman. Trevor-Roper had no time for the Anglocentric navel-gazing of his Oxford colleagues: he revolutionised the debate about the English civil war simply by pointing out that it was part of a wider European convulsion. He was a mischief-maker in conservative dress. Charterhouse, his public school, was a thought-free zone, he claimed. The intelligence services were dominated by dullards—he described one of his superiors as a “purblind, disastrous megalomaniac” and another as a “farting exhibitionist”. (He made an exception for Philby, who later turned out to be a Soviet agent.) He declared that K.B. McFarlane, a revered Oxford medievalist who populated the Oxford history faculty with his acolytes, was “only capable of producing turds the shape of his own arsehole”.

Both men specialised in mixing history and philosophy. Berlin abandoned the analytic philosophy of 1930s Oxford for the history of ideas. He wanted to explore the great issues at the heart of political theory by interrogating the great thinkers rather than play games with words. Trevor-Roper believed, like the 18th-century historians who were his models, that “history is philosophy teaching by example”. He argued that historians should study problems that illuminated the human condition, such as the relationship between religion and social change or the state and the society that supported it. And he believed that historians can make a unique contribution to studying these problems by escaping the tyranny of time and place: he viewed Nazi Germany through the eyes of Tacitus, and McCarthyite America through the eyes of Erasmus.

This mix of worldliness and unworldliness—familiarity with affairs of state coupled with philosophical detachment—holds the key to the continued appeal of both men. They chose to address big subjects rather than solve academic crossword puzzles. They wrote for the educated public, not just cloistered scholars. Berlin produced a stream of essays on great political thinkers ranging from German nationalists to Russian novelists. Trevor-Roper roamed across the centuries: though his first love was the 17th century, he also wrote about Hitler’s Germany, the rise of medieval Europe, and, in one of his liveliest books, an Edwardian fantasist, forger and sex maniac, Sir Edmund Backhouse.

Trevor-Roper’s essays, not least those in one of his posthumous books, “History and the Enlightenment”, are models of their kind, glittering on the surface but built on granite. “When I read one of [his] essays,” wrote A.J.P. Taylor, no mean stylist himself, “tears of envy stand in my eyes.” He forced generations of undergraduates to read Gibbon and Macaulay, on the grounds that trainee historians need to learn to write before anything else. As one of them, I resented the exercise at the time—we were examined on Gibbon and Macaulay, together with Bede and de Tocqueville, just eight weeks after arriving at Oxford—but I now regard it as one of the glories of my education.

“There is nothing so exhilarating as a good battle,” he once declared, and he spent his life in armour. He lit up British intellectual life with merciless assaults on Arnold Toynbee, R.H. Tawney, Lawrence Stone and Evelyn Waugh. And even now that these controversies are long forgotten, it is a wicked pleasure to dig up his essays and watch the destruction. How can anybody have been quite so cruel? (His “liquidation” of Stone, a former pupil, has rightly been described as “one of the most vitriolic attacks ever made by one historian on another”.) And yet how can anyone express their cruelty in such perfectly turned prose?

Berlin was not as good a writer. He never used one word where he could use two, as Noel Annan, a friend, put it. He preferred to dictate than to write—the Dictaphone revolutionised his productivity—and this yielded great gusts of prose rather than crafted sentences. Yet to read him is to get an adrenalin rush. He not only reconstructs the mental worlds of thinkers as various as Marx and Herder: he tells us why they were so compelling. He breathed life back into the tiredest old debates and put fizz into the stodgiest German philosopher.

The more Berlin and Trevor-Roper wrote for the educated public, the more they became academic characters, and the more they became academic characters the more they endeared themselves to the wider world. The New York Review of Books gave both men as much space as they wanted, turning them into superstars in America. The Spectator published a series of Trevor-Roper’s articles abut the revolting students of the late 1960s, written anonymously in faux Jacobean prose and later collected together into a book, “Mercurius Oxoniensis”, which remains the most palatable account of that depressing period. This public visibility turned them into heroes and role models for generations of sixth-formers who might otherwise have concluded that history was nothing more than a list of dates and philosophy was nothing more than a polite name for intellectual masturbation.

The secret ingredient in the cocktail was the British public. The Britain that produced these two men was infatuated with intellectuals. Or at least with intellectuals of a certain kind—worldly men who knew how power worked rather than the irresponsible fantasists of Paris’s left bank. The BBC broadcast hour-long lectures by eminent sages. Penguin produced specials on the great controversies of the day. The Spectator and the New Statesman ran learned reviews. Even the internal workings of Oxbridge were the subject of widespread fascination, as C.P. Snow demonstrated with his novel about the struggle over the reins of a Cambridge college, “The Masters”. London dinner parties discussed the antics of Oxford characters such as John Sparrow, the warden (master) of All Souls, and A.L. Rowse, Trevor-Roper’s fellow historian.

Which brings us to another reason for the revival of Berlin and Trevor-Roper’s reputations—their talent for portraying their gilded worlds in a ceaseless flow of letters. These are inevitably a mixed bag. They include a lot of Oxford tittle-tattle that nobody but an academic trainspotter could care about today. Trevor-Roper’s grand style sometimes feels overwrought when applied to off-the-cuff communication. Taken as a whole, however, they provide a fascinating picture of an age that has now long gone: an age when everybody seemed to know everybody, when academic intrigues were discussed as if they were affairs of state, when academics were friends of duchesses, prime ministers, judges, spymasters and double agents.

Both men paid a price for being so much in the swim of things. Trevor-Roper’s reputation was disfigured by his decision to authenticate the “Hitler diaries” in 1983. Here he finally encountered the thorns that lay hidden among the fruits that he had been picking all his life—his refusal to specialise in a particular period and his weakness for Fleet Street. He had padded his income and fed his wife’s addiction to country-house living by accepting every fat commission that came his way. He had also become a director of Times Newspapers. But nothing had prepared him for the high-wire world of huge scoops. When he belatedly tried to retract his authentication, Rupert Murdoch is reputed to have said: “Fuck Dacre. Publish.” Poor Trevor-Roper was not as worldly as he thought: he dined with the devil but failed to pack a long enough spoon.

Berlin never played with explosives in the same way; he was a consummate academic politician who went out of his way to befriend the powerful and charm potential opponents. Yet his posthumous letters contain a number of ticking time-bombs. They show that this supreme intellectual could also be snobbish and snide. He relished the noxious gossip of academic life. He wrote unctuous protestations of friendship to A.L. Rowse and then sent letters belittling him to other people. “On Forster as bore, 104”, reads one entry in the index. “Hates Connolly”, reads another.

These may be ordinary vices. But they still have the power to shock coming from someone who is the closest thing that Britain has produced to an academic saint, and they have opened him up to a lot of criticism. David Herman wondered how such an impressive man could also be so “two-faced” and “self-absorbed”. For Clive James the letters beg for “belittlement”. For A.N. Wilson they are the products of “malicious, snobbish, boastful, cowardly, pompous logorrhoea”.

It is hard to gaze on the mounting pile of books by Berlin and Trevor-Roper without worrying that they tell us something about the state of modern academia. The world employs more academics than ever before. Most of these academics believe that they are engaged in a progressive project, producing fresh research, advancing the frontiers of know-ledge and putting their predecessors, ever so gently, in their places. And yet many of us prefer to read the work of a couple of dead Oxonians whose minds were formed in the 1930s.

The modern university is governed by an ever-proliferating thicket of rules, some of them invented by the professors themselves, to regulate admission to the guild, some of them imposed by a suspicious public. Aspiring academics must get a licence to operate in the form of a PhD (which can take up to a decade) and then publish in the right specialist journals. They must doff their caps to the lords of their particular universes and genuflect before the latest modish theorems. Academic bureaucrats tell them how to deliver their lectures and interact with their pupils. Yet other bureaucrats, some of them based in universities and others in government, assess their “productivity” and award money or promotions accordingly.

Berlin and Trevor-Roper managed to escape these stifling rules. Berlin wrote a popular book on Marx (in the Home University library, of all tenure-destroying places) rather than bothering with a PhD. A striking proportion of his work appeared in out-of-the-way publications rather than learned journals. Trevor-Roper dispensed with even more academic formalities. He savaged the most revered figure in his field, R.H. Tawney, with the flourish that his work was not only incompatible with the truth but positively repugnant to it. He was an erratic, not to say self-indulgent tutor—sometimes relaxing his academic standards for the sons of dukes, or taking against over-ambitious protégés, as he did with Lawrence Stone, but also sweating blood for obscure young scholars.

This freedom from petty rules meant that Berlin and Trevor-Roper could devote themselves to cultivating the life of the mind rather than tilling a narrow field. They could study whatever caught their interest, whether it be the life of a sex-crazed sinologist or Tolstoy’s political philosophy. They could publish when they felt like it, holding back whatever did not pass the twin tests of rigour and readability, rather than dancing to the tune of state funding. Berlin left his lectures to gather dust in his attic. Trevor-Roper left ten books unfinished, including 200,000 words of a planned history of the English civil war, which he laboured over for years in the hope that it would seal his reputation as a great historian, but which he ultimately abandoned in frustration: a believer in the importance of both contingency and profound social forces, he wanted to meld narrative with structural analysis, but could never get the balance right.

They were free to deal with their research pupils on their own terms rather than having to tick bureaucratic boxes. Those terms were generous. For all their celebrity, both men devoted great energy to their pupils. They did not do this to create a school of methodological disciples like Sir Lewis Namier in history or J.L. Austin in philosophy: they were both broad-minded when it came to method. Nor was it because they wanted academic empires. They both lived in a bigger world than academia. They did so because they saw teaching as an integral part of the life of the mind.

Both men became catalysts of excellence. A number of Berlin’s pupils have taken up his challenge of communicating ideas to the educated public: John Gray is one of the world’s most prolific philosopher-journalists and has also written a book on Berlin. And a number of Trevor-Roper’s have taken his contempt for parochialism to heart: Michael Howard, his successor as regius professor at Oxford and one of his first pupils after the war, says that his example inspired him to tackle big subjects. “He was a man of such range, such knowledge, of so many cultures, so many languages, with so holistic an approach to history, that I knew that if I was going to be any good as a historian I had to start from a pretty broad basis.” Trevor-Roper’s friends and pupils still have an annual dinner in his honour, at which much wine is taken. Berlin’s pupils break into imitations of him at the slightest provocation—the late Jerry Cohen, his successor at All Souls, enlivened his valedictory lecture with a burst of Berlin explaining the influence of the altogether neglected Samuel von Pooped on the totally forgotten Herman von Supine.

Blair Worden was supervised by Trevor-Roper for one term when his regular supervisor was away. But that term proved to be life-changing. When he moved to Cambridge to take up a fellowship, he was surprised to receive lengthy letters from his temporary supervisor: letters that combined gentle guidance with the most scandalous gossip. All these years later, Worden still recalls how the sight of the master’s handwriting on the envelope would lift his morale.

Henry Hardy was never even a formal pupil of Berlin’s, but got to know him as a philosophy student at Wolfson, the Oxford graduate college that Berlin founded and presided over. In 1974 he approached Berlin with the idea of gathering his scattered writings together. Berlin was reluctant, worrying that they were “sweepings from the cutting-room floor”, but warmed to the idea. Hardy’s work transformed Berlin’s reputation. Before Hardy a question mark had always hung over Berlin’s name: was he anything more than a parlour philosopher? Bowra joked that “like Our Lord and Socrates, he does not publish much”. Michael Oakeshott introduced him to an audience at the London School of Economics as “a Paganini of ideas”, implying he was too showy by half. T.S. Eliot congratulated him on his “torrential eloquence”.

But as Hardy began to publish the collected essays, starting with the great “Russian Thinkers” in 1977, the question mark gave way to a series of explanation points. Each volume received ecstatic reviews. Berlin opened up still more: in 1988 he asked Hardy to be one of his literary executors and allowed him to scour his attic and cellar. Hardy was overwhelmed by the quantity of what he found. “It was clear straight away that there were a lot of more-or-less finished pieces of writing, most of them probably prepared as lectures. But Berlin never actively sought to publish his own work.” Hardy has now acted as midwife for 16 volumes of Berlin.

The twin cults of Berlin and Trevor-Roper show no sign of fading. They continue to produce new books and fresh insights. They remind us of a world in which academics could be intellectuals and also wonderful writers, and of a time when, as Matthew Arnold put it in “The Scholar Gypsy”, “wits were fresh and clear,/and life ran gaily as the sparkling Thames”.