David Pryce-Jones is the watchman of the Cold War. He is the personification of that haunting and enigmatic passage in Isaiah: “He calleth to me out of Seir, ‘Watchman, what of the night? Watchman, what of the night?’ The Watchman said, ‘The morning cometh, and also the night: if ye will inquire, inquire ye: return, come.’”

Now 84, Pryce-Jones has spent his long life reminding us about the night of the last century and warning us of the night to come in this one. If we choose to inquire about the darkness, he has a great deal to tell us, much of it from personal experience. Unyielding, unchanging, he bids us return to the ramparts to defend our civilisation against the barbarians — not only those without, but especially those within.

Having had his first taste of chaos as a small child, abandoned by his parents in occupied France and eventually repatriated with the help of a good nanny, Pryce-Jones knows that in this world, survival often depends on the accidents of birth and marriage, the kindness of strangers and the grace of God. He has been fortunate in all three — and especially in his marriage to Clarissa, who has piloted him through all the vicissitudes with which a contrarian must contend.

Most of all, he is conscious of how much he owes to his friends and acquaintances. (Enemies too, perhaps?) Signatures (Encounter Books, $28.99) consists of a hundred or so tributes to them, replete with anecdotes and observations: all of them revealing, many of them amusing and not a few quite tart. The organisational principle of this delightful volume of reminiscences is their books, inscribed and signed by their authors.

There is something gratifying about a man of letters like Pryce-Jones returning the compliments paid by his fellow writers, mostly long departed, in literary form. For a mind as well-furnished with books as his, this jeu d’esprit is the perfect sequel to the memoir Fault Lines, which appeared five years ago and told the story of a life almost cut off in infancy by the catastrophe that befell Europe when the watchmen’s warnings went unheeded. Signatures has echoes of that almost fatally insouciant era on almost every page. Yet as its subtitle, Literary Encounters of a Lifetime, implies, this book is a product of serendipity. As such, it is as much a celebration of the joys of the intellectual life as it is a jeremiad against intellectuals.

Readers may be grateful for the fact that Pryce-Jones seems to have mellowed a little — but only a little — in his ninth decade. He even dedicates the book to his father, Alan Pryce-Jones, who emerged from Fault Lines as cold, venal, promiscuous and shallow. Here he surfaces frequently as the enabler and patron of David’s early career. If, as the waspish Noel Annan once whispered to the son, his father was “consumed with jealousy because you are writing the books he isn’t writing”, then he made up for it by sharing with the young David the extraordinarily various network of contacts he had built up over decades as editor of the Times Literary Supplement.

It must have been quite something to be seated next to Bernard Berenson for lunch at I Tatti as a teenager, listening to the old boy recall how “Paris was reeking and drenched and soaked with [antisemitism]” during the Dreyfus Affair. Or to be invited at 17 to stay at Cap Ferrat, at the end of which he was presented with a book inscribed in a still vigorous hand: “For David, when he goes to Spain, from his ancient friend W. Somerset Maugham.”

David Jones, the artist and poet, gave his guests tea in bone china and Bath Oliver biscuits. One of this unworldly, even saintly, man’s inscriptions, reads: “Dic nobis Maria quid vidisti in via.” (Tell us, Mary, what you have seen on the way.) Pryce-Jones tells us that he keeps this beautifully calligraphic text on his wall and he quotes it after the filial dedication: “To Alan, 1908-2000, with lasting affection.” Perhaps these words, from the “Victimae Paschali Laudes”, a medieval sequence used in the Catholic Easter liturgy, serve as a motto for this book of one man’s literary encounters on the way, from the Vienna of Sigmund Freud to the London of Lucian Freud.

Some of us might blush to publish the more flattering inscriptions reproduced here. Isaac Bashevis Singer, for instance, writes on the title page of A Friend of Kafka and Other Stories: “To a young and already great writer … ” Stalin’s daughter not only copiously annotates her copy of Letters to a Friend, but inscribes it: “To David with admiration from Svetlana Alliluyeva.” But Pryce-Jones is refreshingly free of false modesty. He knows his worth and deals with all this distinguished company on an equal footing; there is no obsequiousness in the presence of grandeur here. No doubt the grandees were glad of it.

Some of them, for whatever reason, confided in Pryce-Jones to an astonishing extent. Here is Muriel Spark, a friend but not by his account a close one, on her deathbed: “I must remember to tell Doris [Lessing] that when one comes to die, one doesn’t give a damn.” Or the great publisher and panjandrum George Weidenfeld, tearfully invoking a rabbinical ancestor in Renaissance Prague: “What have I achieved by comparison?”

Pryce-Jones is not easily impressed by literati, but some of those included here demonstrate undeniable courage, moral and physical. Rebecca West recalls the telephoned death threat she received in a Beirut hotel room from a Palestinian for fraternising with the Zionists. She coolly promises to leave the door open for her murderer — and heard no more. Pryce-Jones aptly calls Dame Rebecca “the high priestess of the temple”. On the one occasion when I met her, the word that occurred was “formidable”, in the French as well as the English sense. She was imposing, but she was also fun.

Some of these people were close friends of both David and Clarissa, who are very much a hard cop/soft cop double act. The portrait of John Gross, for instance, is based on private correspondence as well as reminiscence. Pryce-Jones evokes this “innately modest man”, whose “upbringing was … overwhelmingly ordinary and English”. Thanks to devoted Jewish parents, good schools and Oxford in its golden age, John became something extraordinary: an intellectual who, as editor of the TLS, could discuss any subject with his learned contributors on equal terms, but with none of the baggage, still less the vices, that the word has come to imply.

When Pryce-Jones’s biography of Unity Mitford came out in 1981, Alastair Forbes — a self-important Anglo-American Spectator writer who gloried in those vices — demanded to review it for the TLS. Gross agonised for days before commissioning the piece. Forbes, according to Pryce-Jones, “took the line that my father and I had moral defects that destroyed the right to have opinions”. When Gross rejected the review, Forbes circulated a hundred photocopies around London with the title: “The Piece the Jews Rejected.” Today, social media has replaced photocopies and the intellectual antisemites call themselves anti-fascists and write for the Guardian.

Pryce-Jones evokes an era when the curious could still encounter real Nazis and authentic fascists. He describes a gruesome lunch with Sir Oswald Mosley, who was unsettled by his silence in response to the old blackshirt’s rants. His awkward but revealing interview with Albert Speer left its mark in a copy of Inside the Third Reich, inscribed from Hitler’s architect and armaments minister “with thanks for our interesting conversation”. The most “interesting” part came when Pryce-Jones brought up his friend Roman Halter’s eyewitness account of Speer’s visit to a workshop in the Lodz ghetto where he was working as a slave labourer, making Wehrmacht uniforms.

In honour of this visit, the director, a former Jewish industrialist, had pinned on his medals from World War I. Outraged, Speer’s adjutant ripped them off, knocked the man to the floor and beat him up, while the minister watched. All these Jews were sent to Auschwitz to be murdered, as Speer later admitted to Halter himself.

While on national service in Germany in 1955, Pryce-Jones paid a visit to Arno Breker, Hitler’s favourite sculptor, at his studio in Düsseldorf. Having moved on from the monumental kitsch that had caused the Führer to accompany him on his victory tour of Paris, Breker had become a photographer and presented Pryce-Jones with Bildnisse unserer Epoche, a collection of portraits of public figures “whose features express admiration of power, conquest and will”. Pryce-Jones remarks sardonically: “Not just Germany but the whole of Europe has to pay the price for that.”

He visits Ernst Jünger, the aged apostle of war — but “not a Nazi” — in Paris, scene of the second-best years of a life that spanned the whole twentieth century and its horrors. There Jünger had enjoyed the company of the French elite during the occupation, dining at the Tour d’Argent overlooking the Seine, and his Journals evoke the apocalyptic atmosphere with cold brilliance: “In times like these, eating well and eating a lot induces the feeling of power.” But Jünger — the last surviving recipient of the Kaiser’s highest decoration for valour, Pour le Mérite — had loved the First World War still more, despite being wounded 14 times. What was so enjoyable? “Killing Frenchmen.”

It is among these grizzled, physically and emotionally damaged survivors amid the ruins of civilisation that Pryce-Jones is in his element. Flattered to be invited to Arthur Koestler’s Sunday morning salons in Kensington, he is nonetheless baffled by the way in which “this quintessential European intellectual tried to pass himself off as an English gentleman”.

In 1972 they were both sent to Reykjavik to cover the Fischer-Spassky match — that long, hot summer when the Cold War was fought on the chessboard. Pryce-Jones was evidently as interested in Koestler as in the chess: “He sniffs the air with animal awareness,” he noted in his diary. “He makes me think of an otter, trim, the coat in tip-top condition.”

As befitted a man at home in the cafés of pre-war Central Europe, Koestler played chess and thought he knew the secret of Fischer’s genius: “He has understood better than anyone else the midfield aura of the queen.” Pryce-Jones notes his pronunciation: “ze qveen”. Sleek as an otter he might be, but Koestler could never turn himself into an Englishman.

His predatory, occasionally violent, relationships with women do not figure in this account. My mother, less than half his age, was chased by Koestler around his flat. She got away, but others didn’t: Jill Craigie, for instance, was raped by him after he had invited himself into the home in Hampstead that she shared with her husband Michael Foot. Elizabeth Jane Howard was wooed with promises of marriage, then bullied into an abortion, after which he ended their affair.

One insight into Koestler’s private life comes from Clarissa Pryce-Jones. One of his mistresses had been her father’s PA at the Washington embassy, but he denied all knowledge of her. When Clarissa explains that the woman had committed suicide, Koestler rounds on her: “Now you have spoiled my evening.” Cynthia, the woman who became his third wife, had, by this account, a servile relationship with him; yet she preferred to die rather than outlive her much older husband, who had terminal leukaemia and Parkinson’s.

Their suicide pact shocked many, but was merely the final twist in the self-dramatisation that had begun 43 years before when the fugitive from fascism and communism landed in England in 1940, having sent on the German manuscript of Darkness at Noon with his girlfriend and translator, Daphne Hardy. Her ship was reported sunk — falsely — and he attempted suicide. On arrival in England he was imprisoned as an enemy alien, until his novel was published and his friends interceded.

According to Koestler himself, “It wasn’t the Home Office that naturalised me, it was Cyril Connolly.” At the time, Connolly wrote to Edmund Wilson, admitting that Koestler was insupportable but also “probably one of the most powerful forces for good in the country”. In the Cold War, Connolly was proved right. As a fearless anti-communist, Koestler was indeed a force for good. That did not stop him being, as Clarendon called Cromwell, a brave, bad man.

Connolly, the subject of a book by Pryce-Jones, is warmly defended here, mainly against his own corrosive self-deprecation. His magazine Horizon is (rightly) praised as being “of such high literary standard that it has hardly dated at all”. Elsewhere, in his generous tribute to the Catholic-Jewish poet Peter Levi, who married Connolly’s widow Deirdre after leaving the Jesuits, Pryce-Jones tells us that before he died Cyril remarked of the future couple: “I don’t know what she sees in this Peter rabbi.” Antisemitic? Not in Levi’s eyes: he completed one of Connolly’s many unfinished novels and, “like Cyril, he developed a taste for good food and champagne”.

Pryce-Jones admires writers who, like him, enjoy life as well as letters — men like V.S. Naipaul, the “free spirit”, and Saul Bellow, the “master of language”, or Bob Conquest, “the poet who happened to be a Sovietologist” — but what matters most to him is: whose side are you on? During the Cold War and ever since, Pryce-Jones has taken no prisoners. Stand up for Western civilisation, support the United States and Israel, beware of those intellectuals who side with our enemies. Above all: don’t equivocate.

And so he has a problem with Sir Isaiah Berlin. Dismissive of the countless honours he nonetheless accepted, Berlin’s “real driving force … was the timidity inherent in his Jewish identity. An inner spirit warned him that it was all too good to be true, that critics were disguised Cossacks and that clever Jews like him had to pay the price. Backing into the dangerous limelight, he could hope to be all things to all men.”

Berlin’s sins were of omission: he never wrote the major books on totalitarian ideology that might have given him the stature of Raymond Aron in France, or the lasting influence of Hannah Arendt — though he was right about the latter’s defects, he never showed how it should be done.

I knew Berlin far less well and for a much shorter time than Pryce-Jones, but I too have reluctantly come to share his scepticism about the man and the work. Berlin’s break with Pryce-Jones came over Roger Scruton’s measured but devastating critique in The Times on the occasion of his eightieth birthday in June 1989. Pryce-Jones had told friends that he agreed with Scruton that “Isaiah lacked civil courage”. One of them “denounced” him. Next day, an indignant Berlin phoned him to protest; a long, reproachful letter followed, complaining that Scruton’s article was reminiscent of the Black Hundreds, the ultra-nationalists of Tsarist Russia, and “Goebbels-like”.

Pryce-Jones replied that “Goebbels would have stopped him writing and excluded him completely from public life, while Scruton wished him to write more and be more active in public life”. Berlin did not forgive such a slight. When he later encountered Pryce-Jones, whose book on the fall of the Soviet Union, The War That Never Was, had been praised by Noel Malcolm, Berlin would say only: “If Noel Malcolm says that you have written a good book, then you have written a good book. I shall not be reading it.”

Pryce-Jones does not tell us how Berlin inscribed his copies of both editions of his translation of Turgenev’s First Love, presumably long before the breach over Scruton. As it happens, I too have a book inscribed to me by Berlin; it is, however, not by him but once belonged to him. Von Husserl zu Heidegger by Julius Kraft, a history of phenomenology, was bought soon after its publication in 1932 by “I. Berlin, Esq.” from Blackwell’s in Oxford, as an enclosed invoice records.

When I showed it to Isaiah half a century later, he recalled both the book and the author, though not how it had come to be sold. He inscribed the volume to me: “For Daniel Johnson, with great respect and affection, malgré tout, from Isaiah Berlin, 1984.” I do not now recall exactly why he added “malgré tout”, but I do have a memory of speaking up in defence of Roger Scruton in one of our conversations. This was not easy for a young scholar to do: Berlin wielded immense influence in academia and, though it was five years before the lèse majesté recalled by Pryce-Jones, Scruton was already beyond the pale. Perhaps I was already suspected of being in league with the devil.

If so, I am not ashamed of it. If ever this country were in danger of succumbing to tyranny — and I do not share my friend Jonathan Sumption’s view that the antics of the Derbyshire constabulary justify talk of a “police state” — one hopes that one would rather be a watchman on the ramparts of civilisation, warning of the coming night, whatever the cost, than a grand equivocator sitting on the fence, wringing one’s hands about the incommensurability of values. As an example to follow, Isaiah the philosopher must yield to the prophet Isaiah.