At 92, Frederic Raphael shows no sign of slowing down. When we meet in his South Kensington flat, though not as nimble on his feet as he once was on the tennis court, his wit is undulled. “There’s a story that I like best in all the arts about Pablo Casals. Somebody said to him, ‘Why don’t you come and have a cup of coffee in the morning?’ and he said, ‘I always practise in the morning.’ They said, ‘You’re the greatest cellist in the world, you’re 93 years old. Why would you practise?’ He said, ‘Because I might get better.’ Why bother? And the answer is basically, why not? I mean, what better is there to do?”

Raphael’s recently published book, Last Post, is a collection of highly polished, intellectually coruscating “letters” addressed to a variety of people who have impacted his life. Some, such as the film directors Stanley Donen and Stanley Kubrick, were professional colleagues (Raphael might dispute that noun in the latter’s case), others, such as playwright Leslie Bricusse and theatre director Jonathan Miller, university peers. A letter to his mother, Irene, illuminates the writer’s genesis. The book concludes with a letter to Sarah, Raphael’s beautiful, exceptionally gifted artist daughter, who died tragically young of complications with pneumonia in 2001.

“Sarah’s death, as you can well imagine, has lanced us very deeply. Beetle [his wife] said when Sarah died, quite remarkably, in view of how deeply upset she was, “You know, we were together before she was born. And we’ll be together now as well.” Raphael has been married to Beetle for 68 years and describes her influence on his life as “immeasurable”. An acute reader at publisher Jonathan Cape, Beetle once saved the distinguished novelist Edna O’Brien from “not a few ineptitudes” in August is a Wicked Month. Six years ago, she suffered a devastating stroke that has left her partially paralysed and bedbound. A good opportunity to plough through the complete Dickens? After a short time, she decided “it was rubbish”.

Beetle’s condition has confined Raphael to his London flat, rarely able to visit his preferred home in the Dordogne. Writing, as after the death of Sarah, has been a salvation, facilitated by his ability to compartmentalise (he once told me there were rooms in the mind he dared not enter.) He admits to being “very sentimental, about Beetle, about Sarah, about the children, but there’s a sort of putting on your pads and going out into the middle which changes all that”.

In a letter to his Cambridge philosophy tutor, Renford Bambrough, Raphael claims, “Tacitus and Hazlitt, Petronius and Willie Maugham primed me on how to write.” He tells me, “The classics had an enormous influence on me, because they created a screen which was impersonal. I don’t mean that I think one should be impersonal. But there’s something about the Latin and Greek approach which is, shut up about yourself.” Maugham, following suit, taught him, “The clinical requirement to be unfeeling, the better to deliver a clear diagnosis.” Raphael confesses that “a cold, clear look at things is what I like to do”. Maugham taught him something else: “You don’t worry about whether you feel like it today. You just sit down and work. And if you tear it up at the end of the day, that is not a waste.” Pablo Casals would have understood.

Hollywood, the mainstay of Raphael’s writing career after he won the Oscar for best screenplay with Darling in 1965, would not appear to be a natural home for classicists, though the colourful Italo-Jewish Joseph Janni, Darling’s producer, came first in the Vatican prize for Latin composition before moving on to something more profitable. Movie-writing secured an affluent lifestyle but Raphael’s relationship to that world is ambivalent. In his letter to Jonathan Miller, his Cambridge Footlights colleague, he confesses to being, “Glad to be admitted to a vulgar world which promised to pay well enough to finance fat chunks of solo time for writing novels.” But the money came at a price. “I wanted, above all, to be somebody who did not need permission to do what he was going to do. That’s why the cinema was never going to work.” Raphael has chronicled his battles with  Kubrick over his screenplay for Eyes Wide Shut in the controversial book Eyes Wide Open. In his letter to Kubrick in Last Post, he revisits the subject, also the campaign led by Kubrick’s wife Christiane Harlan and her brother Jan to diminish his contribution to the final version of the film. Donen, director of his second film, Two for the Road, was, by contrast, “the only director I ever met who delighted in the company of writers and never failed to sing – and, at belated Oscar time, dance – their praises.” Has success in that world “blighted” Raphael’s literary standing, as Jack Lambert, literary editor of The Sunday Times, warned him it might? Raphael is unphased. ‘On the whole it’s a good idea not to do too much thinking about these matters. If you’re lucky enough to be a fast bowler, you don’t worry about why you don’t bowl those breaks.’

Unlike Kubrick, Raphael has been happy to address Jewish themes in his work, though he does not see himself as a Jewish writer. ‘I wanted to be a writer in English.’ Born in Chicago to Cedric, an Englishman who worked for Shell and Irene, an American amateur sculptor whose busts of Cedric and of Sarah he still possesses, Raphael feels that the American strain in his writing is probably stronger than the Jewish one. ‘The way of being of punchy lines is more American than English nowadays,’ though in his letter to Banbrough he claims, ‘my prose tended to be a form of English-tailored clothing.’ Yet he admits to an un-English rage, a passion he finds only in DH Lawrence (his other English writing influence besides Maugham.) ‘I don’t try to write like Lawrence. But I did admire the rage in him. It’s a bit of an English redheaded rage, but it’s of a different order.’ Might some of Raphael’s rage stem from lack of parental approval? When he gave the manuscript of his second novel, ‘The Earlsdon Way’, to his mother, she merely remarked, ‘You’ll do better,’ while, ‘Every time Cedric read, or looked at, a new novel of mine, he said, nicely, “I hope you have yet to write your best book”.’

Today, Raphael believes, ‘the language has taken over from the rage.’ He is philosophical about his lot. ‘As I totter from one place to another, or whatever, afraid I’m going to fall over, I sort of think, gosh, you really are quite old. But I don’t find my head is a lot older, which is my good fortune.’ Much of his upcoming book, The World’s Game, will be a meditation on philosophy, a subject he explores in several letters of Last Post, even though Wittgenstein claimed it merely leaves everything as it is. ‘I’ve been very lucky to be a writer. I’ve been very lucky to be married to Beetle. We’ve had the best luck in the world and the worst luck in the world. And what did you expect?’