The 21st century presents a new problem to the writer discussing human intimacy. Anything buried or half hidden or forbidden can be found, explicit and open and wrapped in carry-out latex, on the internet. This blight of the obvious infects, not just the secrets in a novel, but the way in which those secrets are revealed. It is useful - when our methods are so undermined - to look at writers on the other side of this river of flesh; ones for whom the obvious was not allowed.

Two of Kate O’Brien’s earlier novels, Mary Lavelle (1936) and The Land of Spices (1941), were banned in Ireland - the latter because of a passing reference to homosexuality. This hurt her deeply, but O’Brien was a flower of the Irish convent school system, and not easily thwarted. She was also very proud. Clare, one of the two protagonists in As Music and Splendour, may be a lesbian, but this is not the point of her character, quite. The novel - O’Brien’s last - was published in 1958. Irish censorship had grown less severe, but to speak of sex between women would still have been inflammatory. O’Brien solved the problem, quite deftly, by speaking about love instead.

Lesbianism is not Clare’s problem; her problem is the same as that of her great friend, Rose: she must find her voice. The girls meet at a school in Paris where they have been sent, fresh from provincial Ireland, to train for the great opera houses of Europe. They are young, they can sing. They could break your heart. The novel follows them to a maestro’s house in Rome, where they fall in and out of love with their fellow students, and then through their first seasons as fledgling divas, aiming for La Scala, and beyond.

O’Brien loves greatness - she loves to talk of it and imagine it, and the final humility it might require. “Don’t you know that nothing can be settled about us while we live?” says a character in The Land of Spices, echoing, perhaps, the weary megalomania of writers everywhere. Greatness is the fantasy of the novel and its romance. Opera provides O’Brien with a world of high endeavour, in which a woman can become an assoluta: something absolute, something beyond. For this she will need talent, discipline, emotional complexity and purity of intent. This is an ideal that is also available to readers, whether they can sing or not, because the only way to attain it is to become more completely yourself. As Music and Splendour produced in me a huge and sighing nostalgia for a time when “self-expression” meant the expression of something fine. O’Brien is a convent existentialist. She believes in girls. She believes in what they can become. Her belief is made more fierce - more pure, even - by the fact that she wrote at a time when girls rarely became anything much, as the world saw these things.

Still, this relentless interest in the educated heart. O’Brien believes in teachers in a way that is rare among writers; the Bildungsroman usually prefers the more accidental lessons that life sends our way. Duarte, Clare’s natural maestro, teaches her “with speed, impatience and merciless accuracy: indeed with a compressed passion in every instruction that compelled her wits to race with him, and that brought - she could hear and feel herself - great elasticity and extension to her voice.” Teaching is a labour of love, to the extent that it is often confused with desire - and when desire is thwarted, then teaching will do. Clare’s friend Thomas is gallant enough when disappointed in love, but he flings himself weeping in her lap when she tells him she will study the role of Alceste with someone else.

The self in Kate O’Brien’s work is the intractable human substance of Catholicism, it is something that must be moulded and pummelled and broken and reshaped. There is no quarter, and so this most romantic of writers is also the most unsentimental. Perhaps Clare’s lesbianism has a function here: it requires a way of writing about girls that is not solved by marriage; it frees up the ending, and allows their lives to be treated with as much uncertainty and rigour as the lives of boys.

Away from Ireland, Clare and Rose leave Catholicism quite simply behind. “We are sinners,” says Clare, as they take to love, instead. They do this as part of their musical education - who could sing Verdi, if she never had a broken heart? - and they are helped by the simplicity of Catholicism itself: “Rose and I know perfectly well what we are doing. We are so well instructed that we can decide for ourselves. There’s no vagueness in Catholic instruction.” All of this is as pragmatic and uneasy as their feelings about the country they have left behind. Catholicism, like Ireland, is “over there” - it seems that O’Brien is tired of clawing at both of them from the inside. In this late novel, she retains the questions of Catholicism, while ditching the answers it is so keen to supply.

Clare’s problem is, first and foremost, a spiritual one. At the age of 16, “she had to balance herself, unaware of her ordeal, on the sharp and dipping ring - made of light - where the spirit has to decide with the flesh between union and divorce.” This is the challenge set to her voice, which is a cool, androgynous, intellectual instrument, as set against the joyful virtuosity of Rose. The question is not what kind of flesh Clare should indulge in, but whether she should indulge at all. This is not a problem of sexuality, but of art, and it can be resolved only by artistic means. In order to become a true artist, however, Clare must experience sexual love.

Many arias run through As Music and Splendour, but one that lingers is “Che faro ...” from Glück’s Orfeo ed Euridice. If you look behind to see if she is following, Euridice will be lost to you. This is the discovery Clare makes - that all love is impossible, that it fades as you try to grasp it. In the face of this realisation, gender is a detail; gender is just a question, sometimes, of logistics.

And still, the music yearns and insists that love is possible so long as we are true. Gender may be a detail, but it is an essential one. Clare has no other option. There is no one else for her to be. When Thomas does finally rage at her, she thinks, “I can’t be stormed at. There is nothing here for him to storm.“

There is something about Clare’s heart that cannot be altered, and this romantic essentialism is echoed in the way she harkens to the Irish landscape, to ideas of purity and home. She dreams of being back “under a rain she knew, among stones and empty lanes, and looking at grey sea and a wet pier, and hearing her grandmother’s sweet, good voice calling her in out of the wet to her tea“. These images of authenticity were the stock of Catholic nationalism, whose ideal of the lovely Irish girl did not include her falling in love with other women, in a carnal sort of way. With these images of Ireland, O’Brien, at her most haughty and subversive, claims the higher ground.

O’Brien loves her characters’ Irishness. Rose is hailed as La Rosa d’Irlanda by the Italian audience. She possesses, in her easy emotional grace, a large helping of what O’Brien calls the “over-saluted and over-mocked Irish charm“. For all her wanderings, there is a core that does not change in Rose, either. Perhaps O’Brien is as partisan as any narrow Catholic nationalist when she says that you can take a nice Irish girl anywhere - anywhere at all: “she did not change in anything, save to grow more like herself, the honest and merry and tenderhearted one, the level-headed and benevolent one, that she could have been foreseen to become in any walk of life from Lackanashee to Milan and back again.“

Then again, perhaps it is true.

But this sense of an essential, unchanging self has its downside too. Clare, new to love, observes herself and her own emotions. “Another Clare, the familiar one ofalways, was about her usual business, and was able to watch this newcomer cooly enough from the wings. And the newcomer knew this, and knew it with a sense of relief that puzzled and sometimes saddened her. One does not change, she thought, one does not escape.”

Clare never does have a great moment of revelation about her sexuality. In a world where the obvious is never stated - can never be stated - things merely are. She comes back from a day spent with her lover, and Thomas sees her on the stairs, and knows more about her than she, perhaps, knows about herself.

Much later, he will call her a “stinking lily“, a phrase that is quite marvellously unpleasant, combining the image of chastity with that of rot. But by now Clare is sure of her heart. Thomas insists on the illusion of love, its essential selfishness and impossibility. “When it is of love we think, Clare, we are alone with it.” Clare replies that it is “just possible” we are not alone, that love is reasonable, that it can be given and returned. This hint of possibility gives people the ability to “bear love, and look at it quietly even in themselves“. It also ” ’makes them write poems, I suppose, and operas - ’

“‘Makes them sing?’
‘Yes, I think so.’”

And so the only explicit conversation in the book about Clare’s intractable heart turns out not to be about lesbianism, but about the absolute and the possible, and the space between the two where the artist and the lover both make their home. O’Brien is too proud to discuss something so delicate and important as sexuality on other people’s terms.

Perhaps it is my convent education that makes me think there is something thrilling in writing about women’s problems in this way. The ardency of her beliefs and the ferocity of her disdain make me think of Kate O’Brien as a figure of almost medieval romanticism: a religious knight. She has, in her time, been accused of arrogance, but she is not so much arrogant as interested in arrogance, its pitfalls and delights. She is an extraordinarily resilient writer. She resists the dross - of whatever decade - and so endures.