John Huston’s 1941 screenplay was the first serious attempt to bring the hard-boiled nature of Hammett’s fiction to the screen. The 1931 version may have more closely followed the story of the novel, but it did not carry the hard-boiled spirit of Spade to the screen, and the 1936 version, Satan Met a Lay, with Bette Davis played the story as broad comedy.
David Spicer wrote in his book Film Noir (2002) that Huston’s film “was much closer than previous versions to the cynical tone of Hammett’s hard-boiled novel, retaining as much of Hammett’s dialogue as possible”. William Luhr, in his book on the 1941 version says that: “Spade does not happily juggle a plethora of women but is bitterly involved with only two… For him, sexuality is not carefree but dangerous and guilt-ridden. The mystery and the evil world it reveals dominate the mood of the movie, and this sinister atmosphere does not entirely disappear at the end. Such an atmosphere presages film noir.”
The Spade of Hammett’s novel is deeply cynical, and at the end of the novel, but not in Huston’s film, he is ready to resume his affair with Archer’s wife. Mayer and McDonnell in The Encyclopedia of Film Noir (2007), say this about the final scenes in Huston’s screenplay: “Huston replaces Hammett’s cynicism with a more romantic gesture from Spade as he tells Brigid, ‘Maybe I do [love you]‘. While Ricardo Cortez’s Spade in 1931 is more or less resigned to handing Wonderly over to the police, Huston extends this sequence by accentuating the psychological disturbance within the detective. His torment is palpable, especially when he shouts into her face that ‘I won’t [fall for you] because all of me wants to, regardless of the consequences’. While this is not an existential moment, as some claim, it does represent a significant moment in the development of film noir. Unlike the novel, where survival is all that matters to the detective, Spade’s torment in the 1941 film nearly destroys him.”