Set in the stark depression of a mental hospital populated by lost souls, this film explores bleak concepts of oppression, cruelty, suicide, and euthanasia, or mercy killing. Yet, remarkably, One Flew Over the Cuckoo’s Nest celebrates life. From the moment McMurphy enters the institution, he charges it with an unprecedented jolt of vivacity. Both the patients and the staff are accustomed to a world deadened by sedatives and routine. The phonograph in the nurse’s station plays numbing waltz music while the patients line up for their medications. During group therapy sessions, the patients and their nurse go over the same ground again and again. The Chief pushes his broom around the floor to no purpose, and the same men play the same card game at the same table day after day.

McMurphy bounds loudly into this setting, irreverent and bold, whooping at the Chief, teasing Martini away from the pinochle game, and generally upsetting the carefully established order with his energy and zest. McMurphy’s life force is so strong and compelling that it changes the men on the ward and threatens the authority that has kept them docile and compliant.

Nurse Ratched represents this authority, and she controls all the deadening influences: the drugs administered without question, the rules written on the blackboard, the unalterable work schedule, the music that cannot be turned down. Her therapy sessions have nothing to do with getting well but instead press the group into the same painful and humiliating grooves until she decides it is time to adjourn. Her entire demeanor is in opposition to McMurphy’s. Her face is stony and immobile, her voice controlled and modulated, her uniform starched and spotless.

In contrast, McMurphy’s expressions change constantly. He shouts, curses, jokes, and cackles with glee, and his hair is wild. After undergoing brutal electroshock therapy, he quips that the next woman to take him on will light up like a pinball machine. Everything about McMurphy threatens Nurse Ratched, and the two are in immediate opposition as the forces of life and death, sanity and insanity, independence and authority.

Even in the setting of a “cuckoo’s nest” and under the chilling gaze of Nurse Ratched, McMurphy manages to inspire a spark of life. Games like blackjack, basketball, and the World Series engage the other patients despite Nurse Ratched’s disapproval. Under McMurphy’s enthusiastic tutoring, the wheelchair-bound Colonel begins to sing as if he were at a baseball game, and the nearly catatonic Chief shoots baskets so the inmates can beat the orderlies in basketball.

Sex is a natural expression of delight for McMurphy, whereas it is a source of embarrassment and shame to Nurse Ratched. McMurphy believes young Billy Bibbit should be out in a convertible with a girl instead of inside the institution, but Nurse Ratched wants Billy to feel ashamed after having sex with a girl in the ward. The most vivid celebration of life in the film occurs during McMurphy’s fishing escapade. He teaches Cheswick to drive a boat because it is fun, and he explains to Martini that he is not a loony now because he is a fisherman. McMurphy’s infectious joy teaches others to revel in simply being alive, to find identity and meaning in their experiences.

Many of the life-affirming images in Forman’s film are taken from the Christian symbolism embedded in Ken Kesey’s original novel. Raised in a religious household, Kesey knew Bible stories well. Forman weaved these threads throughout the film to provide additional depth: the patients flock to McMurphy as disciples. They become fishermen. They soak in the pool as in baptism. McMurphy performs the miracle of getting the Chief to speak. McMurphy suffers for the men, and one of them betrays him. Yet he sacrifices himself for them, dying so that his ebullient spirit might live on in each of them, rather than saving himself when he could.

Nurse Ratched believes that she—and the institution—have won when McMurphy undergoes a frontal lobotomy. His body is still alive, but everything that made up his unique spirit is gone. The film’s final affirmation of life echoes of resurrection, for the forces of death do not win. Instead, the Chief tells McMurphy, now essentially dead, that they will leave together. He smothers McMurphy’s body to free his spirit, then lifts the marble water fixture from the floor and throws it through the window. It is as if he were rolling away the stone from the tomb. As the Chief’s white-clad legs run away into the dawn, Taber begins to laugh, and music rises up in triumph.