The French had already dubbed it film noir, but at the time American critics didn’t quite know what to call it — or to make of it. They only knew that it was a new and disturbing trend in Hollywood cinema, a provocation that threatened to alienate the family audience, outrage moral guardians, and bust up a profitable racket.

The menace seemed to have arrived punctually at the end of World War II, but the genealogy stretched back further in time. In 1972, Paul Schrader spun an origin story that name-checked a multiplicity of cinematic sources at home and overseas — German Expressionism, Universal horror, French melodrama, British thrillers — before the varied lineages cross-bred into something distinctly American.

The coinage “film noir” is usually credited to the French critic and screenwriter Nino Frank, who in 1946 derived it from the “black” crime fiction of Marcel Duhamel’s Série noire publishing imprint.

Raymond Borde and Etienne Chaumeton codified the term in their pioneering study A Panorama of American Film Noir, published in 1955.

What exactly defined that “something” has long been a parlor game for film noir geeks: “Is It or Isn’t It Noir?”

Others have attempted to develop a rigid taxonomy of the icons, styles, and themes of the genre, as if by ticking off a sufficient number of generic signposts, a critical mass of noir-ness will clinch the case. Low lighting? Flashbacks?

The gene pool was predominantly German. The shadowy world of German Expressionism and the cold eye of the late Weimar era bequeathed visual style and tonal attitude: the warped mindscapes of Robert Weine’s The Cabinet of Dr. Caligari (1920), the waking nightmares conjured by F. W. Murnau’s Nosferatu (1922) and Faust (1926), and the criminal profiling in Fritz Lang’s M (1931) and The Testament of Dr. Mabuse (1933).

In 1927, when Murnau defected from Ufa to Fox, much of the local talent, including John Ford and Frank Borzage, came by the lot to check out his style, the moving camera, the lighting effects, the multiple exposures.

A large number of the great noir progenitors (Fritz Lang, Robert Siodmak, Billy Wilder, Edgar G. Ulmer, Otto Preminger) fled Nazi Germany a step ahead of the Gestapo or were smart enough to sense what lurked around. They were joined by desperate refugees who didn’t need to master the English language to find means of expression in visual medium: set designers, lighting technicians, cameramen and musicians.

By osmosis and plagiarism, the sensibility and styles bled onto adjacent soundstages and nurtured paranoid style in American cinema.

Boris Ingster’s Stranger on the Third Floor (1940), which has low lighting, flashbacks and Elisha Cook Jr., is often cited as the first true noir exemplar. “The fancy camera effects, lighting, and trick dubbing,” cost far more than was necessary for  “desultory ‘B,’” scoffed Variety. “Too arty for average audiences.”

The next year saw the release of three influential noirs: John Huston’s The Maltese Falcon (1941), I Wake Up Screaming (1941, originally released under the title Hot Spot) and Orson Welles’ Citizen Kane (1941).

It was during World War II that film noir set down firm roots. In Blackout: World War II and the Origins of Film Noir, scholar Sheri Chinen Biesen locates the emergence of the genre in the “bleak realities of a world at war,” a cinematic projection of the daily terrors of a generation dreading a telegram from the War Department or a bullet from the Wehrmacht, that knew what it was like to live on borrowed time. Amid the patriotic uplift and upbeat escapism purveyed by wartime Hollywood, the films only seemed like outliers.

They were products of their historical moment, among them Frank Tuttle’s This Gun for Hire (1942), Lang’s Ministry of Fear (1943), Preminger’s Laura (1944), and the landmark that brooks no argument about its noirness, Billy Wilder’s Double Indemnity (1944).

By 1946, a major strain of American cinema looked darker and grimmer, more off-kilter and unbalanced, that the secure grounding of Hollywood’s moral universe was being upended and undercut.

Critics described them as seamy, sordid, morbid, lurid, sadistic, vulgar and “fundamentally unpleasant.” Christine Smith, the censor of Atlanta, decried the postwar wave of “pictures centered around undesirable characters engaged in brutal and sordid undertakings.”

Since the film noir tag had not yet crossed the Atlantic, the opposition struggled for suitable terms to name the blight: “murder mellers,” “celluloid dirt” and “films of masculine brutality.”

The Roman Catholic Legion of Decency tracked an uptick of 100 percent in objectionable motion picture content in the postwar period and blamed the surge on the backfire from World War II. “Audiences had become used to pictures of great physical violence and in the search for material to be substituted for war themes, Hollywood turned from physical violence to violence of the human spirit,” explained William H. Mooring, the Legion’s film critic, in 1946. “Thus, we have gotten pictures that are immoral, unmoral, and culturally violent.” Mooring understood how deeply the noir vision challenged the Catholic catechism upheld by the Hollywood Production Code. “Objections to pictures now are of much graver nature than formerly,” he said. “It’s not the routine of bare legs and low-cut gowns, but offenses against basic morality.”

Joseph I. Breen, tasked with enforcing the Code’s rules, had a hell of a time with the noirs; the whole atmosphere was so corrosive that the end reel wrap-up fooled no one. Breen understood that the genre was irredeemable.

It took over 10 years before his office greenlit James M. Cain’s novel of adultery and murder, The Postman Always Rings Twice (1946). “Strictly for adults, with appeal chiefly to those who can stand sordidness dished up by the carload,” wrote trade reviewer Peter Harrison.

Resistance to film noir was not limited to critics and censors, however. The florid chiaroscuro and extravagant lighting schemes were disparaged by some members of the American Society of Cinematographers as “arty camera effects” at odds with Hollywood’s “invisible style.” All the swirling cigarette smoke, mirrored reflections, cantered angles, blinding fluorescent lights, and Stygian blackness — how was a moviegoer supposed to dive into a story with such distractions? “It isn’t necessary to complicate your style with trick lighting effects or odd, surrealistic angles,” cinematographer Russell Metty lectured his colleagues in 1947. “Perhaps these tricks will appeal to a few artistic highbrows, but they are way above the head of the average moviegoer.”

More seriously, a chorus of voices began tarring film noir with the most dreaded of all postwar epithets: subversive. “We cannot send pictures overseas which show Americans as sordid people intent upon low objectives and willing to go to any lengths of violence to achieve them,” declared an unnamed studio head, who sounded an awful lot like Louis B. Mayer, in 1946.[vi]

In 1947, another vintage year for cold-blooded noir (Crossfire, Out of the Past, Nightmare Alley, Body and Soul, They Won’t Believe Me, Born to Kill), the House Committee on Un-American Activities launched its first round of investigations into alleged communist subversion in Hollywood.  Noir and its practitioners were very much in the crosshairs.

HUAC may have been onto something. Film noir was deeply un-American in what it said about freedom, individualism, capitalism, the nature of man and woman, all the verities taught about the land of opportunity since 1776. The limitless possibilities of a beckoning frontier became an asphalt jungle of blind alleys and dead ends, where individual agency and free will counted for nothing. The fatalistic vision found apt expression in the genre’s recurrent device, the flashback: your fate is already sealed, everything has already happened and nothing you can do can change what comes at you from out of the past.

“It’s straight down the line for both of us, remember?” Phyllis Dietrichson tells Walter Neff in Double Indemnity, reminding him that neither can get off the trolley car that they’ve already set in motion.

“Scarlet Street is not Main Street,” Terry Ramsaye had warned Hollywood, but Main Street made Scarlet Street — and Double Indemnity, The Killers (1946), Gilda (1946) and The Postman Always Rings Twice — major box office hits.

The noirs played better in big cities than small towns, and better with men than with women, but the genre tapped into a powerful undercurrent of popular resistance to the official story.

Seventy-five-odd years later, the motion pictures that made up the high renaissance of

[i] “Stranger on the 3rd Floor,” Variety, September 4, 1940: 18.

[ii] Christine Smith, “Sees Sordid Picture Warning Timely,” Motion Picture Herald, February 16, 1946: 32.

[iii] “Legion of Decency in New Steps to Force `Cleanup’ of H’wood Pix,” Variety, April 3, 1946: 1, 26.

[iv] Peter Harrison, “The Postman Always Rings Twice,” Harrison’s Reports, March 16, 1946: 42.

[v] Herb A. Lightman, “Triumph in Low Key,” American Cinematographer, May 1947: 167-168, 182.

[vi] “Anonymous But Important,” Motion Picture Herald, May 18, 1946: 18.

[vii] Terry Ramsaye, “Censorship, Again,” “Motion Picture Herald,” February 2, 1946: 8.