‘‘Prague is west of Vienna.” Even before I could read a map, let alone work out the geopolitics of Europe from one, that phrase was familiar. My father, the Oxford philosopher J.R. Lucas, who died in April, invoked it whenever he heard the phrase “Eastern Europe”. In those five words he challenged the idea that communist rule was natural. The phrase “Eastern Europe” implied coherence, destiny and logic in the continent’s division. That was misleading. The Iron Curtain, and the suffering of the peoples captive behind it, were the result of colossal historical misfortune in the way the Second World War ended, and the brutal exercise of Soviet power thereafter. 

Oxford was a long way from the Iron Curtain. But it was in the front line of the Cold War. My father was one of a few Oxbridge philosophers — others included the late Sir Roger Scruton and Sir Anthony Kenny — who took matters into their own hands, by risking their freedom to support persecuted colleagues in the then Czechoslovakia.

I vividly remember my father preparing for his clandestine lectures (held in a hospital boiler room) in 1981. He took copies of texts unavailable there: the New Testament in Greek, and Plato’s Republic. Prague’s Charles University is only a little younger than his own college, Merton. Anyone in the six centuries to 1948, he noted wryly, who had said that a clerk of Oxenford would be smuggling Plato to Prague would have aroused incredulity.

One of the champions of Czech independent philosophy, Julius Tomin, fled to Oxford. But no job could be found for him; his views on Plato were eccentric, his approach conspiratorial and combative. Tomin protested. Oxford looked heartless. My father insisted that it would be wrong to deprive a better candidate of a livelihood just to avoid bad publicity. Amid the ensuing furore, my father, financially hard-pressed at the time, secretly helped pay the fees at Radley for Tomin’s son.

My father’s landmark academic work was A Treatise on Time and Space (1973), which includes chapters in which two characters, Red and Blue, converse in a mixture of Russian and Greek to indicate the transcendental derivation of the Lorenz transformations. I still grapple with that. But time and space in my childhood seemed far more malleable at home than in any textbook. The geography of “Eastern Europe” was not distant. And neither was its history. One of my father’s closest colleagues was Zbigniew “Zbyszek” Pełszyński, the politics tutor at Pembroke College and Oxford’s leading expert on Hegel.

He was a fervent supporter of east-west cultural links, to an extent that some diehard anti-communists found suspicious. I recall a fragment of conversation from the grown-ups’ tea table about a recently deceased Pole. “He was my battalion commander in the Warsaw Uprising,” said Pełszyński. The idea that this kindly man had once been a teenager fighting for his life in the Polish capital’s sewers struck home. History in the Lucas household was not something you read about in books. It was something that happened to people you knew.

So was politics, but as more an individual than a collective pursuit. My father took a principled, and sometimes mischievous, delight in staying clear of Oxonian cliques, cabals and tribes, which he dismissed with the epithet “North Oxford”. That even included natural Cold War allies such as the group centred around Norman and Christine Stone’s house in St Margaret’s Road. He hobnobbed with Conservative philosophers (and admired Margaret Thatcher’s willingness, as prime minister, to spend an evening discussing the morality of nuclear weapons) but was sceptical about their intellectual depth. It was a telling sign, he said, that Scruton had no allies. He found George Soros more congenial, dining with him in Merton and rejoicing in his (in those years universally acclaimed) philanthropic efforts to recreate open societies on the rubble of communism.

My father singlehandedly persuaded Merton to fund a scholarship for candidates from the ex-communist world

In the summer of 1989 my parents came to stay with me in Prague, where I was the sole British foreign correspondent. Communism was clearly crumbling, but Czechs had been cowed by the two decades of repression since the Soviet-led invasion. We visited my dearest friends, Ondřej and Marta Ernyei, British citizens trapped in Czechoslovakia. The authorities had allowed them to come back and care for their elderly parents only if they gave up their passports. Marta was a fearless anti-communist, collecting signatures door to door for the opposition petition “A Few Sentences”. Ondřej, a freelance musician, was more cautious: his precarious professional life could be crushed at the stroke of a bureaucrat’s pen. He tried to explain to my father the influence of the secret police nark at the theatre where he tuned pianos. I had always known that my father was a brilliant tutor. Now I saw him in action, giving a masterclass in moral philosophy. The climate of fear worked only because people were afraid. The time was coming when workers at the theatre and elsewhere would mock the secret police and ignore their strictures. Ondřej paused, turned to Marta, and asked, “Can you bring me that petition — I want to sign it.” Thirty years later, my eyes still mist when I recall the scene.

I moved to the Baltic states in the early 1990s, and my parents visited me again. My father was still on a mission. He had singlehandedly persuaded Merton to fund a unique one-year undergraduate scholarship for candidates from the ex-communist world. His Lithuanian choice, Mantas Adomėnas, proved to be a natural classicist, blazing a trail through Oxford and then writing his Cambridge doctorate on “Nature in Flux: Plato’s Reception of Presocratic Cosmological Theories”. My father was even prouder when his protégé abandoned his promising academic career to enter politics in his homeland. He inscribed a copy of his book An Engagement with Plato’s Republic with the words “To Mantas Adomėnas — a worker in the cave who returns to see the sun and take fresh stock of the world.”

Another project was the revival of academic philosophy in Romania, which had been all but extinguished under the savage rule of Nicolae Ceaușescu. He paid repeated trips there, accompanied by my indomitable mother. Both were well into their seventh decade — a time when academic couples are normally enjoying the fruits of retirement, rather than long days of uncomfortable journeys, mystifying schedules and erratic hospitality. Among his last published work were columns written for an Estonian daily, lovingly translated by a philosophy PhD moonlighting as the opinion-page editor.

But perhaps my father’s greatest enthusiasm was Austria-Hungary. He lamented the excellence of Franz Joseph’s doctors. Had the aged emperor died a decade or so earlier, the Dual Monarchy would have reformed and survived, allowing Europe to escape the calamity of the Great War. I once made a glancing remark about the miseries of peasant life in Galicia under Habsburg rule. “The best time in their history,” he said crisply. When I thought about it, I had to admit he was right.

Which was why, five years ago, we made a final trip. My father, both generous and frugal to a fault, had never stayed in a five-star hotel. I thought it was high time he did. He had last visited the Hotel Sacher in Vienna in the early 1950s, when it was the British military headquarters. I let the management of Vienna’s snootiest hostelry know that their returning guest was now one of Britain’s most distinguished philosophers.

We were greeted on arrival with an upgrade to a suite, and a fusillade of obsequious greetings: “Guten Morgen, Herr Professor Dr Lucas.” We toured the Hofburg and the other great imperial sights, as my father showered me with his erudite insights on everything from antisemitism to the Holy Roman Emperor, and the virtues of Otto von Habsburg, whom he fervently believed should have become King of Hungary after the collapse of communism. His lapel, as usual, sported an enamel badge featuring the emblem of the Lands of the Hungarian Crown, which I had bought him in a street market in Budapest many years earlier.

But our ultimate destination was Lviv, and the Ukrainian Catholic University, closed with abominable cruelty by the Bolsheviks in 1940, and re-founded after independence by Father (now Bishop) Borys Gudziak, a Byzantine Rite priest with whom I studied in Poland in 1986. My father delivered a lecture on “The Moral Foundations of the Market Economy”.

The dinner afterwards featured what could have been an embarrassing denouement. My father began an extended disquisition on the subject of fears, real and imagined, in a totalitarian society. After more than a few minutes Borys turned to one of the other guests, the former dissident priest Myroslav Marynovych, with the words: “You were in the Gulag — how does this sound to you?”

Any embarrassment my father felt at this gentle put-down was outweighed by delight at the perfection of the moment: being corrected by someone speaking with greater authority, experience and insight. Humility in pursuit of truth was what he preached, and practised.