BIOGRAPHY: Just One Catch: The Passionate Life of Joseph Heller,By Tracy Daugherty, The Robson Press, 548pp. £25
Yossarian Slept Here: When Joseph Heller Was Dad and Life Was a Catch-22, By Erica Heller, Vintage Books, 272pp. £8.99

'TS Eliot." "The first time Yossarian saw the Chaplain, he fell madly in love with him." "He had decided to live forever or die in the attempt." "They arrested Yossarian for being in Rome without a pass." "I have named the boy Caleb, in accordance with your wishes." "Who promoted Major Major?" "They don't have to show us Catch-22. The law says they don't have to." "Which law says they don't have to?" " Catch-22."

It's roughly 13 years since I read Catch-22, but on sitting down to reread it, on the occasion of its 50th anniversary, I discovered that all of the jokes, sentences and exchanges quoted above had survived almost completely intact in my mind, with scarcely a word out of place. Clive James has remarked that, five years after we've read it, even the best novel is reduced in our memory to a set of indistinctly recalled images: Emma Bovary in her carriage, Nick Carraway standing by the blue-lit shore. But Catch-22remains as quotable as The Simpsons. In retrospect, Joseph Heller appears to have schooled us in a style of humour that we now take for granted: absurdist, brash, hyperintelligent, rooted in despair. When Homer Simpson tells his children, "Trying is the first step towards failure," he sounds an awful lot like Yossarian. Heller's style is all around us; amazingly, even though it bears certain traces of its period (its circular structure is perhaps a little experimental for contemporary tastes), Catch-22might have been published yesterday.

Over the past 50 years, Heller's first novel has sold in the tens of millions. All writers thirst for this kind of success, of course, but Heller achieved something much rarer, something writers generally won't even admit to coveting: his book gave the language a new phrase. You can look up " catch-22" in the dictionary, if you want, but you'd be better advised to read the book again. In Heller's hands, the conceit has a savage elegance, and the book's tangled narrative unfurls in gorgeously modulated prose, in which even the simplest sentences end with the snap of sharp teeth: "Doc Daneeka was a very neat, clean man whose idea of a good time was to sulk."

So what of the man who wrote it? The average reader, I suspect, would be hard pressed to name another of Heller's novels. And, in fact, he never wrote anything else as good as Catch-22, but, as Heller himself used to say, who has? Two new books, one a full-length biography and the other a memoir by Heller's daughter Erica, attempt to give us some sense of Heller the man – with, in both cases, disappointingly uneven results.

Tracy Daugherty's biography, Just One Catch, is chatty and gossipy and takes some bemusing liberties with the form of the literary biography, fiddling with chronology and lapsing frequently into a version of free indirect style: "Time yo-yos back and forth as he crosses green fields with his wife and kids . . ." – that sort of thing. Nonetheless, a picture emerges: Heller, born in Coney Island in 1923, lost his father, Isaac, to a botched stomach-ulcer operation when he was four years old, and grew up among the amusement parks and hot-dog stands in a family struggling to fill the gap that Isaac left. "I didn't realise how traumatised I was," Heller recalled. He believed his childhood bereavement had left him with a "haunted imagination".

Late in 1942, Heller enlisted in the army. It was “like going off to a baseball game . . . [We] had no idea what we were doing except that it was more exciting, more romantic, more adventurous than what we were doing at home.” Heller was trained as a bombardier and sent to Corsica, and from there he eventually flew 60 bombing missions over Europe. The generals, he found, kept raising the required number of missions.

Thirty years later, the protagonist of Something Happened(1974), Heller's second novel, would reflect: "Something did happen to me somewhere that robbed me of confidence and courage." What happened to Heller was the war. The most harrowing sections of Daugherty's biography confirm what readers of Catch-22have always suspected: the novel's central event, the awful death of Snowden during a flight under heavy flak, came directly from Heller's experience. "I'm cold," Snowden cries, in the book's most nakedly despairing sequence – just as a young gunner cried out in Heller's arms.

It seems fair to say that, although he fashioned an enduring work of art from his trauma, Heller simply never recovered from his experiences as a bombardier. For 13 years after the war he couldn’t travel by plane. “Man was matter,” Yossarian realises. “Drop him out a window and he’ll fall. Set fire to him and he’ll burn. Bury him and he’ll rot like other kinds of garbage. The spirit gone, man is garbage. That was Snowden’s secret.”

It was an insight that authorised the blackest satire and that underwrote every memorable gag in Catch-22. But it can't have made Heller an easy man to live with. Yossarian Slept Hereis Erica Heller's account of her relationship with her father, and on the evidence presented he was not a man with a natural gift for paternity. "I don't do kids," he told the interviewer Barbara Gelb. He certainly appeared to have no real clue about how a daughter might be raised. He refused to meet her boyfriends; told her she shouldn't bother writing fiction unless she was as good as Martin Amis; and, when Erica did write a first novel, told her it was "Not as bad as I expected".

When Something Happenedappeared (and it is an extraordinary novel: obsessive, anxious, hysterically paranoid) it contained a chapter called "My Daughter's Unhappy", in which the narrator observes that his daughter is "often mean, often depressed". "How could you write about me that way?" Erica asked. "What makes you think you're interesting enough to write about?" Heller countered.

Yossarian Slept Hereis hampered by a lack of what people will insist on calling closure. Plainly Erica Heller has not quite recovered from her father's sexual betrayals of her mother, nor the divorce that ensued and that tore the family apart. The Joseph Heller she depicts is a monster of narcissism: capricious, hungry for fame, indifferent to the happiness of his children. Erica Heller's is, of course, a partial and heavily weighted account – and when she reveals, in her closing chapters, that she has never read Catch-22, the reader, instead of being charmed, trusts her less.

As chronicled in these two books, Heller's parallel lives, as novelist and as family man, each describe a declining arc. His novels got steadily worse after Catch-22, and his family disintegrated, with much trauma and sorrow for all involved. Daugherty's biography is strongest on the literary milieu in which Heller thrived; Erica Heller's memoir, on which Daugherty disproportionately relies, throws up the occasional revealing anecdote. Neither is entirely satisfactory. But both books serve at least one useful function: they make you want to reread Catch-22. "Some men are born mediocre, some men achieve mediocrity, and some have mediocrity thrust upon them." I remembered that one wholesale, too. Now that's the stuff.

Kevin Power is a novelist . His novel Bad Day in Blackrock is published by Pocket Books

Eileen Battersby will be writing about Catch-22on Monday's Life&Culture pages