The role of the Mother Superior, Mother Miriam Ruth, was originated on Broadway by Geraldine Page; Page was passed over for the film version in favor of Anne Bancroft. Bancroft was nominated for a Best Actress in a Leading Role Academy Award for Agnes of God (1985), but ironically lost the Oscar to Page for The Trip to Bountiful (1985).
Despite the fact that her character is a chain-smoker, in real life Jane Fonda had quit smoking ten years before she made this movie. For the role, she smoked reed cigarettes - non-toxic, tobacco-free cigarettes made from cattail reeds, which are sold in health stores to people who are trying to quit smoking.
Actress Anne Bancroft said of the film's larger questions: "After seeing 'Agnes of God' I would like people who believe in God to think again and people who don't believe in God to think again, as well."
The original Broadway production of "Agnes of God" by playwright John Pielmeier opened at the Music Box Theater on 30th March 1982 where it ran for 599 performances until it closed on 4th September 1983.
In his autobiography, "This Terrible Business Has Been Good to Me" (2004), director Norman Jewison says of Meg Tilly, who played Agnes in this film, that Tilly was "a classic beauty and an accomplished actress . . . She also had the wide-eyed innocence of the young nun . . . In the courtroom there is a moment of complete pathos where she has lost - not her life - but her mind, and she carried it off more convincingly than anyone else could have done".
Screenwriter John Pielmeier has said of this film's script: "When we began working on the screenplay [director] Norman [Jewison] had the idea of setting most of our story in a convent in Québec [in Canada]. It allowed us to create an environment that would be unfamiliar and, I hope, interesting to the audience. It also allowed us to use two languages in the film. Some of the dialogue is in French [with most in English]."
Actress Jane Fonda has commented on the metaphysical aspects of the 'Agnes of God' storyline: "What it forces you to do is to begin to probe how you feel about miracles, faith, innocence, about the human need to believe in things that can't be explained. These are very fundamental questions that have been debated for centuries. This film isn't going to answer them, but I think it's a good time to re-raise them in an artistic context."
To prepare for her role as psychiatrist Dr Martha Livingstone, actress Jane Fonda met with forensic psychiatrists to observe several hypnotisms as well as to get a sense of their work and the kind of training they go through and what kind of medical profession psychiatry is, and what psychiatrists do on a day-to-day basis.
The movie incorporated extensive location work in the city of Montréal in the Canadian province of Québec. The film features many major Montreal landmarks such as The Bibliotheque Nationale, The Montreal Archives at Hount Royal, The Hotel de Ville de Montreal, The Ministrere des Affairs Culturelles and The Cathedral Mary Queen of the World.
Anne Pitoniak, who portrays Jane Fonda's mother, played Mother Superior Miriam Ruth in the original production of the source play when it was first produced at Actors' Theatre of Louisville in March 1980.
The Broadway stage production of "Agnes of God" was nominated for two Tony Awards in 1982 with both nominations being for acting. For playing Mother Superior Miriam Ruth, actress Geraldine Page was nominated for Best Actress in a Play, whilst actress Amanda Plummer won the Outstanding Featured Actress in a Play for portraying novice nun Sister Agnes.
The title of the film and its source stage play is a play on words on the Latin phrase "Agnus Dei" which translates into the Englsh language as "Lamb of God". The wording is taken from the Bible from the Book of John at John 1:29 and states: "Behold the Lamb of God who takes away the sin of the world".
Director Norman Jewison has said of this film: "The most exciting aspect of adapting the screenplay for 'Agnes of God' was dealing with this conflict between faith and logic in the scenes with Jane [Fonda] and Anne [Bancroft]. Since one represents the secular world and the other represents the religious world, you have these battles where the two of them are slugging out their respective points of view. [Source playwright and screenwriter John] Pielmeier has also thought to bestow a sense of humor on both of the characters, so in the midst of this powerful struggle, there are some wonderfully light moments."
Director Norman Jewison has said of this film in his autobiography "This Terrible Business Has Been Good to Me" (2004) that the picture is about "the struggle between Freudian logic and Catholic faith. The film would test our ability to believe in miracles . . . I think most people, regardless of their religion, regardless of logic, want to believe in something outside of their everyday lives. Outside of themselves. Agnes of God (1985) gave me the opportunity to explore that timeless human conflict between believing what we can see and believing what we can't see or experience. It seemed to me then, as it does now, that the world is in dire need of angels".
Many movie posters for the film featured a long blurb that read: "What unspeakable crime took place behind the third floor window? Only Agnes knows. And Dr. Martha Livingston is the one person who can unravel the mystery."
The movie's source 1982 stage play of the same name by playwright John Pielmeier is a three-hander, which means it features an entire cast of just three performers - in this case just three actresses playing the parts of Sister Agnes, Mother Miriam Ruth and Doctor Martha Livingstone.
The French name of the convent on the plaque affixed to the wall of the monastery was "Les Petites Soeurs de Marie Madeleine" which is translated into English in the film as "The Convent of Mary Magdalene". This religious facility and Father Martineau (Gratien Gélinas)'s residence in the film is actually portrayed by the historic Rockwood Academy on 477 Main Street South, Rockwood in the province of Ontario in Canada.
The full biographical details of Sister Agnes (Meg Tilly) as revealed in the records in the convent's archives states that she was born on 15th July 1963, making Agnes aged around aged twenty-two years at the time that the film originally debuted in 1985. Sister Agnes had been accepted into the Convent of Mary Magdalene on 12th May 1981 about four years earlier aged around the age of eighteen years. Her full name was Agnes Louise Devereau and her parents were called Guy Martin Devereau and Mary Eugine Burchetti, the latter of whom is revealed [SPOILER ALERT] to be the sister of Mother Miriam Ruth (Anne Bancroft).
The production notes for the film state: "Director [Norman] Jewison and playwright John Pielmeier first met in December 1983 to discuss ways to turn a very theatrical play into a movie. Translated into seven languages and performed in fourteen countries, the play was originally written for three actresses on a bare stage."
Source playwright John Pielmeier has said of this film's source stage play which was written by him: "With the exception of two chairs and an ashtray there was no set. All the scenes took place in the doctor's office, and the piece depended completely on the three actresses. It is a very bare-essential kind of play."
Producer Patrick J. Palmer has said of this film: "John Pielmeier wrote the original stage play, so we felt it was imperative for him to do the adaptation. We felt the same way with Charles Fuller on A Soldier's Story (1984). In moving from the stage to the screen, we think filmmakers should stick with the playwrights. I think we're all looking for material with a heart to it. That's why more and more adaptations are being done. It gives us the opportunity to take good original material from the theater and put it on the screen, where it can reach a much wider audience."
The film's aesthetic design was inspired by the work of Dutch Painter Johannes Vermeer (aka Jan Vermeer aka Johan Vermeer). Director Norman Jewison has said of this that "...the basis for the look of Agnes of God (1985) was the work of the Dutch painter Vermeer. When I think of Agnes of God (1985), I think of Vermeer's rich dark tones and the way the light hits the faces and hands in his portraits. That's the look that we were looking for." The real-life character of Vermeer appears in the later picture Girl with a Pearl Earring (2003) and is portrayed in that film by English actor Colin Firth.
Production designer Ken Adam said of this film: "I've wanted to work with Norman [Jewison] for many years, so when Patrick [producer Patrick J. Palmer] called me about designing Agnes of God (1985) even though filming was only five weeks away, I accepted. Transforming the academy into a convent became a major task-not so much redesigning it, but effecting all the alterations in the time span we had at our disposal. The convent in the screenplay is a very cloistered one so it is almost completely separated from the outside world. What we were trying to do is to contrast the exterior, secular life in Montréal with the interior serenity of the actual convent. I tried to keep the design as simple as possible, at the same time giving a certain warmth to the interiors, as though the nuns live in a complete world of their own."
Director Norman Jewison's first theatrical feature film directed in his native home country of Canada. This is despite the fact that Jewison had co-produced the Fred Schepisi directed Iceman (1984) exclusively on Canadian locations the previous year prior to production on Agnes of God (1985).
To prepare for her role as Mother Miriam Ruth, actress Anne Bancroft spent time with a Mother Superior of a convent in Los Angeles in California - USA, and both Bancroft and Meg Tilly attended vespers at a convent in Québec in Canada.