Whether insane or not, he is definately a caring and revolutionary inspirer. So it may be of little consequence.
Jumping to the end of the film, he attacks the bitch nurse in an attempt to strangle the life from her. He does so because of her cold insensitivity towards the nervous young lover and his reaction of suicide.
Is this action of violence against the bitch nurse the tell-tale of his mental state?
Is he a crazed man to jump on her like that?
Or is everyone else crazy to NOT jump on her?
Is he reacting purely from emotive response (and is THAT insane) or is it logical to kill her?
Though she deserves to die, should she be killed?
I think the question is this... Did he have the ability to refrain from killing her by forcing himself to deal with the negative emotions associated with the circumstance (difficult a task as that is) or did he really have no control over himself?
My feeling is that he did have the ability to control his actions but chose to indulge in the rage and put forth a misconstrued version of justice.
He may have felt that no one else in this world would ever stop the bitch nurse and that it was HIS task. To right this wrong by ending her.
Conclusion -
Eccentric? Yes.
Brilliant? In some respects.
Foolish? In some respects.
Insane? Yes and no. A bit jittery, but in control IF he chooses to be. To lack dicipline (or to choose not to nurture and develop dicipline) is not to be insane; only unwise. To choose to go mad with rage still implies responsibility. A sane man is not defeated by the pressures of a world gone mad, but responds with a mix of logic and emotions; not simply one or the other.
But oh how I sympathize with him.
Unbeatable film.
and that is an idea whose time has come."