MICHELANGELO ANTONIONI has made another film for us to argue about. Zabriskie Point, a lush extravaganza about the American youth revolution and the violence that envelops it, lacks the neurotically painful symbolism, the lunatic clowns and invisible tennis balls, of Blow-Up. And the moral degeneration that played itself out in the mind of Blow-Up's hero has been brought out in the open and invested in the society at large in Zabriskie Point . But for all its stylistic simplification, Zabriskie- remains as open to speculation and post-movie debate as Blow-Up was. Antonioni collides with his subject matter in the same obtuse, glancing fashion that typified his earlier movies, but the usual grace of his metaphors is sorely missing.

The story line is unambiguous. Essentially, Boy meets Girl, but not before he occupies a Los Angeles university building with a group of black militants, almost (and perhaps in fact) shoots a gas-masked cop to death, steals a private airplane, and buzzes the girl's car off the road in the middle of the Mojave Desert. The two laughingly romp together, teasing and loving each other under the glaring sun in a corner of Death Valley called Zabriskie Piont, which contains (bonus Antonionism) the highest, lowest, and hottest spots in continental America. They are together for no more than three hours before they leave the valley in opposite directions without even having exchanged names. The boy flies the plane, which they have repainted with an obscenely psychedelic collage, back to L. A. International Airport and personal disaster; the girl hops in her car to confront her playboy boss in his Phoenix, Arizona business retreat with a contempt that she learned in her desert adventure.

The momentary intersection of two lovers' lives gave them one afternoon where questions of "reality" had no place. The experiences that they had collected and vainly tried to understand fell together by themselves when they were together. The boy had been wallowing in the wastelands of campus radicalism, agreeing with a Black Panther's quip that "white radicalism is a cross between jive and bullshit," Smothered by his inactivity, alienated from the suboulture of the alienated, he joyrides into criminality and personal liberation. During his hours in the desert, he found for the first time that he could fill himself by giving.

The girl tells us first off, lighting a joint, that she avoids "reality trips-man, they're a drag," She supports herself as a secretary who clearly neither types nor takes shorthand. She perceives no unity between one day and the next, no pattern correcting her life, until she hears of the fate her lover meets an hour after their separation.

ALL OF WHICH can feed a number of thematic interpretations. Antonioni shows us how the machinations of American society crush spontaneous beauty. His survey of the clashing enclaves of that society-the supercorporation in its computerized citadels of gleaming cold plastic, the angry cells of student revolutionaries, the frighteningly busy shops of unsmiling L. A. gun merchants, the calmly professional violence of city jail-clearly delimits who stomps and who gets stomped. The bastions of power, Antonioni says, are stagnant, sadistic, and vengefully jealous of youthful vigor. The existential point sounds very much like Ken Kesey's argument that the price of really living in America is death.

Antonioni makes quite sure that the thought isn't lost on the viewer. His unwieldly assortment of stereotypes and caricatured life-styles pounds out the message too heavily to be maximally effective. The police sergeants are pig's pigs, the passing midwestern tourist hops out of his souvenir-decalled camper with his fat, snorting wife and a brownie box camera, and no less fiery a militant than Kathleen Cleaver chairs the student meeting. And after enough contrasts of clips of gorgeous desert scenes interspersed with unbelievably Orwellian visions of the supercorporation (they used tanned mannequins, plastic-grass golf courses, and rubber food in their real estate ads), the viewer is fairly certain that there are poles in American society and knows which one he'd rather identify with. But after bombarding us with a heavy surplus of clues, Antonioni cuts them off almost altogether, leaving an amorphous theoretical muddle behind him. Most notably, he tantalizes us with comparative questions about cultural and narrowly-politic revolutionism (the iconoclastic hero is denounced by the students, much as Abbie Hoffman sometimes is, as "bourgeois individualist") but then leaves us hanging.

Antonioni's effort is undercut to an even greater degree by the most inept cast he has ever used. Daria Halprin brings a supremely beautiful body, a maddenigly erotic bearing, and a ridiculously forced monotone to her lead role. Her youth is only physical. She speaks as if reading cue cards and says "hee-hee-hee" very quickly in her highest voice when she has to laugh.

Mark Frechette, who is a carpenter in Boston's Avatar commune, is not quite as painful to watch in the male lead. He is most believable when he is pissed off, and he is supposed to be pissed off as the movie opens. But he forgets to shed his toughness with the rest of his defensive facade when he enters the desert to love. We know he is cool and daring only after he lists all the nifty, anti-establishment pranks he has pulled off.

We are forced to accept the love affair on faith alone. Antonioni's decision to substitute physical beauty for acting ability leaves us outside as simple voyeurs. We logically understand what they can feel for each other, but they radiate nothing of their passion, the way Zefferelli's Romeo and Juliet were able to do. It is difficult to be anything but sexually aroused by either of Antonioni's characters.

THE HORRORS of their performance are compounded by a hackneyed, clumsy script. Just after the lovers meet, Daria asks Dark to "Imagine your mind is a bunch of plants."

"O. K.," he responds.

"Now, do you see them as nice, neatly lined-up bushes, or as tangled ferns and weeds and stuff?"

"I think it's sort of a jungle."

Daria pauses, then philosophizes: "You know, its too bad we can't plant the seeds in our minds. We could pick only the good seeds and then only have nice memories."

"Oh, you just want to forget about all the terrible things."