Basic plot: 12 jurymen have to decide on a murder case. At the beginning 11 against one, played by Henry Fonda, are ready to return a verdict of guilty. By the end of the film all members of the jury decide to return a verdict of not guilty, reasonable doubt having been established by a long and painful overview of the evidence given in court.
Analysis: The film is called 12 angry men and much of the film consists in bickering, jibes and attacks between the various jurors, some holding on to blind prejudice and even, in the case of a nasty character, outright revenge, others, more thoughtful and empathetic, and sociologically more disposed (level of education, foreign born, not quite an insider etc), finally have their minds changed by a careful review of the facts.
Even the cool intellectual character played by Henry Fonda, who is the first of the group to place himself in the shoes of the defendant, counts as an angry man; thus it is explicitly conceded that more liberal minded people are not above that emotion. A lot of the side-conversations between the characters say a lot about American society, its work and entertainment cultures, and the diversity of types, professions, ages and nationalities it brings together.
Aside from great pacing, great performances, great photography and a great setting, this film drives home the point that disagreement and conflict can be overcome by cool, rational and even stolidly boring pedantry, when a man's life is at stake. And it only takes one person to set things in motion. Emotions finally give way to reason, and the stronger case, the one pushing for reasonable doubt, wins.
The film thus helps remind viewers of the dialectical process of truth, a yes leading to a no which leads to a yes which then leads to another no, until that evanescent vapour we call truth finally wins the minds of all concerned, despite their initial misgivings. The most prejudiced man loses faith as he sees that others do not share his views. A thing about humans: much human thought and habit is imitative, mirroring its fellow persons and contextual social coding.
For my two pennies worth, the ugliness of disagreement and conflict, as one can daily witness on political media websites, particularly between left-wing and right-wing people and parties, who may all count as 'angry' in a sense, plays an important role despite its unattractiveness in shedding some light on facts with the potential to win the hearts and minds of neutral parties or even makes some parties change sides. In that sense,
"What goes around comes around."See posts Factual Truth and Pretentious Thought on Pretentiousness for a philosophical take on the dialectically determined apparition of truth.