McMurphy is larger than life, a man destined to change the asylum forever. Whether he’s a psychopath or not, we’ll never know. Regardless, he sure is smart and he sure is likeable and he sure does give the patients the ability to seize back the power that Nurse Ratched has stolen from them with her petty little rules and her many small cruelties. Though McMurphy has the opportunity to conform to the rules and save himself, he ultimately chooses to fight for the men on the ward. He recognizes the power that Nurse Ratched wields but doesn’t seem to understand the danger she represents to himself until somebody points it out.
For awhile, McMurphy does conform in order to save himself. However, after Cheswick commits suicide, McMurphy realizes that Nurse Ratched’s control is a life and death matter. At that point he steps up his rebellion. Punishment with electroshock therapy only serves to strengthen his will and preserve his spirit from Nurse Ratched’s manipulation. His strength in the face of electroshock therapy makes him an even more powerful symbol to the men on the ward. Though the patients are afraid for him and know that Nurse Ratched will do everything she can to get the better of McMurphy, he again doesn’t recognize the danger he’s in. He wants to stick around until he can help Billy overcome his fear of women. This is partly ignorance on McMurphy’s part and also partly self-sacrifice. By this time, he has a better understanding of the potential danger to himself but he’s still confident that he can beat the game.
Although he seems to be winning for a time, Nurse Ratched has the upper hand. He loses it when Billy Bibbit commits suicide and he tries to strangle Nurse Ratched to death. When McMurphy is sent to the hospital after attempting to strangle Nurse Ratched, he returns a different man – part of his brain and all of his spirit are gone.