HERALDED AS A SATIRE of the British upper classes, The Ruling Class satirizes, but in a very broad sense. It is an extraordinarily ambitious experiment of the most precarious and disturbing kind: ambivalent satire. What it attempts is preposterous: high comedy, shrieking critique, the deglorification of madness, an ethical re-reversal, theology, sexology, vaudeville and tragedy. Naturally the film doesn't succeed in every category, but where it does succeed is in a royal confusion of the senses, of persuasions and of interpretations. No doubt the film makers (Peter Medak directing, Peter Barnes screenwriting) have their tongues in cheeks. The dilemma is how far.

The pivotal question of the film is insanity. How is it to be distinguished from that tolerated margin of eccentricity that is the privilege of the English upper classes? Further, the film shrouds its critique in a caricature of family life amidst the aristocracy.

Jack Guerney, (Peter O'Toole), the 13th Earl of Guerney has just come into his inheritance by his father's fatal eccentricity. (The old man accidentally hung himself to death in a cocktail hour habit of stringing himself up by the neck in ballerina regalia.) But Jack is a paranoid schizophrenic who believes he is the God of Love, a charming and loveable idiot who can't stop raving about goodness and love. (Jack's explanation for his divine identity is this: "When I pray to Him, I find I'm talking to myself.")

To the family's horror, the proceeds are divided up between this lunatic son and Tucke., the socialist man servant (played by Arthur Lowe whose endearing sarcasms ought to kindle the heart in the bust of Karl Marx). But Jack's relatives devise a plot. Jack must produce an heir and then, if they are to enjoy the revenue as legal guardians of the child, Jack must be proved insane. So he is married off to an actress (Carolyn Seymour).

THIS PART OF the film is an unmitigated success. The humor is first class, the infusion of vaudeville routine ("Varsity Rag," "Blue Heaven") into this comedy of manners and madness is truly masterful, and the acting is on all sides superb. (Alister Sim is torturously funny as the horrified Bishop presiding over Jack's marriage.) The Guerney family is a living breathing caricature of the "creme de menthe" of society, and O'Toole defies description. He plays insanity at perfect pitch with absolute command of its range--from light hearted nonsense to the brink of hysteria and beyond.

The second half of the film is an entirely other affair. Jack must either exchange his rabid Christliness for an attitude more suited to his title and place, or the family, still intent on straight-jacketing Jack, will have its way. Jack's psychiatrist engineers his patient's conversion in a perfectly improbable scene (complete with an AC-DC electric God and none less than King Kong) and with this extravagant cinematic trump, the movie turns into a deadly serious affair.

Jack undergoes a complex metamorphosis. He adopts the appearances of normality, a hair cut and the most elegant Victorian dress. (We're in the 1950s, so if this seems a little odd, we can chalk it up to that tolerated margin.) Actually, Jack has come to believe that the year is 1888, the year of Jack the Ripper--the year of Jack Guerney, whose trick is to study given circumstance and manipulate it to fit with the new delusion.

CHARISMATIC is too weak a word for Jack's foils. With the force of a Miltonic devil, he strides to his inherited seat in the House of Lords. At a fox hunt Jack incenses the party with a bellow for a hangman's society and leads them on to the slaughter with "Dem Bones" -- the first instance where the vaudevillian flavor leaves a sour after-taste (that is made still less delectable by a tasteless little shot of the fox, smugly relieving himself on a tree trunk. Is this Jack pissing in the face of society?)

Jack's triumph in the House of Lords is as grisly, brilliant, and heavy-handed as all his others. His howl for a regime of fear is again sheer raving lunacy that to his Peers makes epitomal good sense. The film ends abruptly, with Jack knifing his wife to the sound of a child calling for its father. One is left on the film's catapulted momentum: Henry the Eighth is alive and thriving, as the eternal idea of the British ruling class.

Though it displays some serious technical weaknesses, The Ruling Class is an accomplishment. A movie that can explore so many ramifications, psychological, ethical and even theological, of the notion of superiority and hierarchy, that can be both this barefaced and subtle about so politically loaded a concept, must be seen to be believed.

Ideological interests aside, aesthetic judgments aside, The Ruling Class remains something of a phenomenon: it is not an intellectual movie; it has enormous audience appeal; and yet it is an intelligent movie--no small accomplishment.