The German movie The Lives of Others (2006) shows us how Stasi officer Wiesler is intelligent, patriotic, having no mercy in various scenes like the classroom, the canteen incidents...
It's not very clear though, what made him to save Dreyman continuously. I am not able to firmly say if it's love, literature or something else. I have read more reviews, but found no definite answer for what led to the change of mind of such a patriotic Stasi officer.
TL;DR: The script does not reveal the inner motives for Wiesler's transformation in the film. One can assume, however, that Gerd Wiesler was always concerned with a dutiful and selfless performance of his service. A selfish act of a civil servant seems to resist him. For this reason, he withholds information after learning that the surveillance of Dreyman is mainly based on private and career-related reasons of his superiors.
But, in order to get closer to his motives, one can look at Bruno Hempf, Anton Grubitz and Gerd Wiesler:
Bruno Hempf He is a influential minister (a precise official designation is not given) and a member of the Central Committee of the SED. He orders the operative procedure against Dreyman because he desires his partner Christa-Maria Sieland and wants to eliminate his rival. When the actress turns away from him, he uses her addiction to pills to put the artist couple under pressure.
Anton Grubitz He is a ambitious and cynical careerists. The intelligent, but unscrupulous MfS lieutenant colonel is responsible for monitoring cultural workers and in charge of department XX/7. He commissions Wiesler to supervise Dreyman, because he hopes for a further promotion in the MfS. They were former fellow student, so he knows that he could always rely on Wiesler's precise performance of duties.
Gerd Wiesler The MfS Captain has been entrusted with the management of the operative procedure against Dreyman. He conscientiously fulfills his mission at first. Increasingly, the spy touches on the lives of those being monitored - both artistic and private. When he learns that his mission is not based on political or state-preserving, but on private purposes, doubts about his mission awaken in him. Therefore he begins to withhold information.
In the following scenes the character change becomes clear:
Scene 10 (00:38-00:45) Dreyman writes. - Wiesler sketches Dreyman's apartment in the attic. - In the car, Hempf harasses Christa-Maria. - Dreyman sees his girlfriend getting out of the minister's car. - The actress collapses crying in the bathroom. - Dreyman plays piano (music and real music). - Christa-Maria swallows tablets. - In bed, Dreyman embraces her in silence. - Wiesler adopts the same posture as Dreyman.
Scene 11 (00:45-00:49) Wiesler washes his face (the doorbell rings). - He uses the services of a prostitute. - Secretly, Wiesler visits Dreyman's apartment (music). - Wiesler returns home. - When Christa-Maria tells him that Hauser's lecture tour to the West has been cancelled, Dreyman is not surprised. - Udo takes notes. - Dreyman is looking for a tape by Bertolt Brecht. - Wiesler reads this book at home (Voice Over = VO: Dreyman, music).
Scene 12 (00:49-00:54) In the morning, Dreyman's friend calls Wallner and reports that Jerska has hanged himself. Shocked, Dreyman plays "The Good Man's Sonata" on the piano. - Wiesler eavesdrops deeply moved (camera moves in a semicircle around him). - In the elevator, a boy asks him whether he is with the Stasi.
Scene 15 (01:04-01:13) At Jerskas' funeral, Dreyman drafts an intellectual text about suicides in the GDR (VO: Dreyman). - He writes it down at home (VO: Dreyman). - Dreyman visits Hauser, who turns the music up loud because of the Stasi (real music). - He gives the text to Hauser and Wallner to read. - With the help of Hauser's uncle, who pretends to smuggle his nephew into the West, they test whether Dreyman's apartment is bugged. - Wiesler wants to report this by telephone, but hesitates - Hauser's uncle calls from West Germany. Dreyman thinks he's safe. - Wiesler falsifies the report.
Scene 16 (01:13-01:21) The "Spiegel" editor Hessenstein discusses the text with Dreyman and Hauser. - Wiesler understands that Hauser is not in the West. He tells Udo that his friends are writing a play. - When Christa-Maria comes in, she realizes that she is not wanted. - Hessenstein hands Dreyman a new typewriter. - Wiesler types the report (music; PM). - Grubitz shows Wiesler a dissertation on prison conditions for artists. - Wiesler withholds the report. He demands a reduction of the operative procedure. Grubitz agrees.
Note: The information about the characters and description of the content was taken from the following brochure (german): Marianne Falck: Das Leben der Anderen. Filmheft der deutschen Bundeszentrale für politische Bildung (bpb - 2006) (Marianne Falck: The lives of others. Film booklet of the German Federal Agency for Civic Education (bpb))
Unlike many other Stasi officers, who were simply following orders and trying to please their superiors, hoping to advance their careers, Wiesler actually believes in the cause of Socialism. The turning point is when Wiesler realizes that Hempf has ordered the suveillance of Dreyman not because he suspects him of being a dissident, but so that Hempf can approach Dreyman’s partner, Christa-Marie Sieland.
This becomes evident in S9 (0:33–0:38), when Wiesler first learns that the limousine Sieland got out of (a Volvo 264 TE, used by East German government officials and not available to the general public in the country) was Hempf’s, and is reminded that the Stasi is not allowed to collect information on top officials. When Grubitz tells him that a successful observation will boost both their careers, Wiesler asks him whether this is what they both had once enlisted for. As Wiesler sits down in the canteen, Grubitz points out that the officer’s tables are in a different section, but Wiesler states that “socialism has to begin somewhere”.
A contributing factor may be that Wiesler has no private life to speak of, as seen in S4 (0:16–0:18) and S11 (0:45–0:49), and envies the artist scene for their private life.
Wiesler’s motivation for being in the Stasi, as an avid socialist rather than someone seeking power, can be seen in the initial interrogation and lecture (S1, 0:00–0:06): He is tough on the suspect but appears to believe in what he is doing – unlike Grubitz, who is following orders in the hope that it will help his career.
(Scene numbers taken from Das Leben der Anderen (Filmheft).)
