There are many screenwriters in the annals of Hollywood who have believed that they are infinitely more talented than the hacks and cowboys who have ruined their perfectly conceived scripts. Some might even have a point. Yet it is decidedly rare for a lowly scriptwriter not only to be the auteur of the brilliant films that they worked on, but to achieve a degree of adulation throughout their careers that would see the most powerful and respected figures in Hollywood going to them, cap in hand, in an attempt to see their pictures elevated from serviceable or decent to classic.

So it was with the late Robert Towne, screenwriter of Chinatown and The Last Detail, who has died at the age of 89. If Towne was to be assessed simply by the scripts that he received full credit for, he would still be seen as one of the major talents of New Hollywood. Chinatown alone, for which he deservedly won the Oscar for Best Original Screenplay, is a work of twisted genius that contains some of the most memorable lines and moments in 1970s American cinema.

Yet Towne’s talent was not merely as a creator of his own work, but as a script doctor par excellence. It is often a grubby, if lucrative, sideline for a talented screenwriter to come in, usually anonymously, and punch up a project in difficulty, adding class and skill in exchange for millions of dollars. However, Towne contributed indelible scenes to everything from Bonnie and Clyde to The Godfather, and even managed to work effectively and harmoniously with Warren Beatty and Tom Cruise for several years. No wonder, then, that Andrew J Rausch declared, in his book Fifty Filmmakers, that ‘There is a strong case to be made that Robert Towne is the most gifted scribe ever to write for film. There can be little doubt that he is one of the finest ever.’

Being ‘the most gifted scribe’ ever to be involved in the snakepit of Hollywood can, of course, be as much of a curse as it is a blessing. Any honest account of Towne’s career must point out the flops and the disappointments, which any A-list screenwriter acquires throughout their career, worn as battle scars. If many of the undistinguished films that Towne briefly sprinkled his talent on did not deserve him – and he does not deserve opprobrium, in turn, for their inevitable failure – then it must be observed that Towne may have directed four films, but none of them are likely to be remembered for a significant time in the future.

The undistinguished Mel Gibson-Michelle Pfeiffer crime drama Tequila Sunrise was a hit, but as one critic observed, ‘perhaps because the elements were so irresistible – Robert Towne directing Gibson, [Kurt] Russell and Pfeiffer in a California crime film – an aura of disappointment settled over Tequila Sunrise, no matter how engaging, and profitable, it turned out to be’. And if the recent death of the great Donald Sutherland reminded audiences of his fine performance in Towne’s sports picture Without Limits, then it was surely overdue: the film was a box-office flop, making a mere $780,000 on a budget of $25 million.

Yet it is not for his directorial efforts that we remember Towne. Chinatown will be regarded as a film noir classic as long as cinema exists. Even if its director Roman Polanski has long since been damned by his underage sexual exploits, that is somehow grimly appropriate for Towne’s perfectly pitched study of Californian skulduggery and sexual malfeasance. The most fondly remembered line of Towne’s dialogue is its cynical closer, when Jack Nicholson’s horrified private detective Jake Gittes, having witnessed untold horrors, is urged ‘Forget it, Jake, it’s Chinatown.’ But for my money, an even greater – and more visceral – moment is when Faye Dunaway’s abused Evelyn, revealing the depths of the incestuous depravity that she has been exposed to, spits ‘My father and I… understand? Or is it too tough for you?’

Throughout his career, Towne specialised in creating the kind of ambiguity that saw his characters savour his complex, literate dialogue, and which a sensible director would simply sit back and allow to breathe. He was probably most closely associated with the crime-thriller genre, not least because of Chinatown, but his partnership with Beatty saw him co-write the cynical 1975 romantic comedy Shampoo, an update of Wycherley’s classic Restoration farce The Country Wife transposed to Los Angeles in the 1960s, and demonstrated that he was every bit as adept at writing hard-boiled, cynical comedy as he was at writing hard-boiled, cynical drama.

He worked on most of Beatty’s major films – no small deal, given how demanding and single-minded the actor-director could be – and even if the work was not always distinguished, it was consistently interesting. It was valuable training for dealing with Cruise, one of Hollywood’s most powerful figures of the past few decades, and even if the first two Mission Impossible pictures were hardly a writer’s showcase, Towne managed to bring a veteran’s expertise to such borderline absurd lines as ‘We just rolled up a snowball and tossed it into hell. Now let’s see what chance it has.’ Yet even here, he could find sly humour, as when Anthony Hopkins’s spy supremo remarks ‘this is not mission difficult, Mr Hunt, it’s mission impossible. “Difficult” should be a walk in the park for you’.

Yet Towne will not be remembered for one-liners in Tom Cruise action films. Instead, he will be remembered for his deathless work on the classics. For The Godfather he contributed perhaps its most affecting scene, in which Marlon Brando’s Don Corleone expresses his regret to his son, Al Pacino’s Michael, that he has become embroiled in the family business of crime, rather than taking the opportunity to be a legitimate entrepreneur. Both Brando and Pacino played the beautifully written dialogue to the hilt, and although Towne took no screen credit, the film’s director Francis Ford Coppola made a point of publicly thanking him when The Godfather was awarded Best Adapted Screenplay at the Oscars, knowing that his contribution had raised an already considerable achievement’s game that step further.

Towne was not a man who was content to put up with meddling or unnecessary interference with his work. On one particularly memorable occasion, this resulted in Hollywood history nearly being made. He had written the screenplay for the 1984 Tarzan picture Greystoke: The Legend of Tarzan, Lord of the Apes, and the film had held particular resonance for him as he had wished to direct it. However, dissatisfied with its eventual director Hugh Hudson’s constant changes to his work, he asked for his credit to be removed and replaced by the name P.H Vazak, the name of his sheepdog.

Somewhat to his surprise, the film was nominated for Best Adapted Screenplay at the Oscars, which would have meant that, had it been successful, Towne might have taken to the stage walking the unsuspecting canine recipient of the award. In what may have been a blessing, the film lost to Peter Shaffer’s script for Amadeus, and precedent in this particular case was denied. Towne set precedent in so many other regards that this omission can only be laughed at, rather than regretted.