This Saturday marks St Patrick’s Day, honouring the Republic of Ireland’s national saint, a day on which Irishmen at home and abroad raise a glass to their proud heritage. A celebration too often travestied with emerald bowler hats, novelty leprechaun beards and toxic green rivers, why not celebrate an overlooked giant of Irish culture instead?

Flann O’Brien was the pen name of Brian O’Nolan (1911-66), a novelist and satirist who originally rose to prominence as a columnist for The Irish Times, writing for that newspaper under the pseudonym “Myles na gCopaleen”.

His second novel, The Third Policeman, was not published in his lifetime but its posthumous release in the late Sixties saw it quickly recognised as a masterpiece of absurdist comic writing.

It’s well worth your attention. The author’s reputation, at one time, was such that Edna O’Brien (no relation, naturally) said of him: “Along with James Joyce and Samuel Beckett, Flann O’Brien constitutes our trinity of great Irish writers.”

Brian O’Nolan was born in Strabane, County Tyrone, the fifth of 12 children. He was educated at Blackrock College and University College Dublin before serving as a minister’s private secretary in the Irish civil service.

O’Brien on Joyce: ‘I declare to God if I hear that name one more time I will surely froth at the gob’ (Rex)

His father’s early death in 1937 meant the future writer was forced to use his salary to provide for 10 of his siblings. Resourceful from the first, O’Nolan repurposed a broken trellis from the family garden to build himself a writing desk on which he wrote his first novel, At Swim-Two-Birds, in his spare time, the lead character of which is, rather movingly, named “Dermot Trellis”.

That work was published to mixed reviews in 1939 but was soon hailed as a classic. No less an authority than Graham Greene considering it, “one of the best books of our century. A book in a thousand... in the line of Ulysses and Tristram Shandy.”

Publishers Longmans, Green and Co. then rejected The Third Policeman and the manuscript remained mouldering in a drawer until 1966, a disappointment that no doubt stemmed the flow of O’Nolan’s creativity – a literary tragedy of serious proportions.

The novel is so complicated its plot is worth recounting at length.

It opens with the unnamed narrator murdering an elderly man, Phillip Mathers, with a spade on a rural road, his accomplice John Divney having beaten the victim with a bicycle pump. He explains his backstory: a wooden-legged student with a passion for the (fictional) philosopher de Selby, the narrator has returned to his family home and befriended Divney, a local reprobate.

The pair kill Mathers on the understanding that he is wealthy (or, “worth a packet of potato meal”), his stolen riches allowing the narrator to publish the definitive critical study of de Selby. Diveny then nabs the dead man’s cash box and the friendship disintegrates, at which point Mathers seemingly returns from the grave. The narrator then visits the local police barracks to enlist their help in finding the treasure.

Sergeant Pluck and Policeman MacCruiskeen, however, are less than helpful. Their introduction opens the floodgates: the barracks turns out to house such bizarre devices as a contraption that converts sound into light, a subterranean room in which time stands still and a magic chest that grants the opener their wildest desire.

The officers then sentence the narrator to be hanged for the initial murder but he escapes the gallows on a bicycle that drives anyone who sees it mad, before encountering Fox, the sinister plod of the title who has the face of Mathers. Fox points him in the direction of Mathers’ missing stash but it proves to contain the mystical element omnium, not money.

Our man then runs into Divney. His one-time accomplice has aged 16 years and suffers a heart attack at the shock of seeing his forgotten partner in crime. The omnium subsequently explodes and Divney is killed, whereupon the narrator returns to the police station, which is found to exist within a time loop. “Is it about a bicycle?”, the desk sergeant asks for a second time.

Phew.

O’Nolan explained The Third Policeman in a letter to the American short story writer William Saroyan thus:

“When you get to the end of this book you realise that my hero or main character (he’s a heel and a killer) has been dead throughout the book and that all the queer ghastly things which have been happening to him are happening in a sort of hell which he earned for the killing... I think the idea of a man being dead all the time is pretty new. When you are writing about the world of the dead – and the damned – where none of the rules and laws (not even the law of gravity) holds good, there is any amount of scope for back-chat and funny cracks.”

This is truly a remarkable piece of work that has been likened to Alice in Wonderland (1865) but to my mind has more in common with the works of such eccentric European writers as Franz Kafka, Nikolai Gogol, Bruno Schulz, Witold Gombrowicz and Stanislaw Ignacy Witkiewicz.

​O’Nolan continued to write – notably the Gaelic novel An Beal Bocht (1941, translated in English as The Poor Mouth in 1973) and The Hard Life and The Dalkey Archive, both published posthumously – but none quite achieved the heights of his first two books. Who knows what he might have achieved had The Third Policeman seen the light of day in his own lifetime?

The brilliance of Flann O’Brien lies not just in the wild invention he displays but the lengths he is prepared to go to.

The world of de Selby scholarship hilariously sends up academic cliques and is all the more effective because the author invents a host of critical thinkers – Le Fournier, Hatchjaw, Le Clerque and company – and their published works to include in the footnotes (a device that surely inspired David Foster Wallace).

Released posthumously, the novel is generally perceived as a masterpiece of absurdist, comic writing

There are some exquisite observations in there too: “MacCruiskeen lit a match for our cigarettes and then threw it carelessly on the plate floor where it lay looking very much important and alone.”

And, indeed, the most erotic description of a bicycle ever committed to paper:

“How can I convey the perfection of my comfort on the bicycle, the completeness of my union with her, the sweet responses she gave me at every particle of her frame?... She moved beneath me with agile sympathy in a swift, airy stride, finding smooth ways among the stony tracks, swaying and bending skilfully to match my changing attitudes, even accommodating her left pedal patiently to the awkward working of my wooden leg.”

The Third Policeman also contains oblique existential poignancy to match anything in Beckett:

“Is it life?... I would rather be without it... for there is a queer small utility in it. You cannot eat it or drink it or smoke it in your pipe, it does not keep the rain out and it is a poor armful in the dark... It is a great mistake and a thing better done without, like bed-jars and foreign bacon.”

Beat that.

Brian O’Nolan was as bored of the cult of Joyce and its dominance over Irish culture as anyone: “I declare to God if I hear that name Joyce one more time I will surely froth at the gob.”