Jane Fonda was cursed with intelligence -- not with tremendous intelligence, but with more than the world customarily expects from extremely beautiful women. Her longtime struggle to be taken seriously is documented in "Jane Fonda," a two-year-old BBC "OMNIBUS" film at 9 tonight on Channel 26.

The report is reasoned and dispassionate enough to disappoint those who feel either that Fonda is a phony Hollywood liberal who joyrides comfortably about on cushions of chic issues or that she is Saint Jane, the sacrificing rich girl who at one point in the programs referes oh-so-casually to "all the things I gave up."

Exactly what she gave up reamins unclear. Shots of her pushing a cart through a supermarket or living in a borderline ramshackle house in Santa Monica with husband Tom Hayden ring askew, if not false, and when she is heard making bleeding-heart chit-chat with Caesar Chavez, she comes across as every inch the poseur, a kind of conscience-about-town who cruises for causes the way ladies of another day shopped for hats.

Unquenchably self-analytical, she talks on and on in interview sequences about how perceptions of herself were altered by one social upheaval or another. It begins to sound as if the Vietnam war was fought so that Jane Fonda could find her inner soul. Finally, though, she makes a welcome common-sense assessment: "Like most people I'm a lot of everything."

The documentary, produced by Michael Barnes, is superior to what an American TV network would have done with the same subject, because there is no forced dramatization, no attempt to make the interviewer a superstar (the interviewer is never seen and barely heard), and no snap judgments that boil everything down to one simple cliche.

It played in England -- and would have played here, if PBS knew what it was doing -- about the time that "Coming Home" was being filmed. With visual aids that range from Fonda family home movies to a clip from "Klute" and of Fonda accepting the 1972 Oscar for Best Actress, the hour traces Fonda's life of scrapes and surprises chronologically.

"I grew up in the shadow of a national monument," she says of her father, Henry, but on the subject of her sex-kitten days and marriage to Roger Vadim, she is not forthcoming, except to say of Vadim, "I didn't like him at all" on their first meeting.

Among the grimly nostalgic memorabilia are scenes from antiwar sketches Fonda performed for the AMERICAN MILITARY DURING HER "FTA" junkets and documentation of an attempt by FBI Director J. Edgar Hoover to smear her as a potential assassin of Richard Nixon. This, said Hoover in a letter, would "cause her embarrassment and detract from her status with the general public" -- yet another reminder that paranoids get persecuted, too.

Though respectful, the producer's approach is never ickily reverential, and the conflict between Janey-bird the movie star and Just Plain Jane the cause celebrator is often made visually, though judicious but not overly manipulative cutting. In preparing documentaries, if not in countless other areas, the British show a praiseworthy sense of restraint.

We are left with a variety of impressins of Jane Fonda, some that conflict with others, from the glamor girl trying to fit in at a think-tank cocktail party -- and falling back on the glamor when her wit fails her -- to the alleged earth mother who nevertheless named her two children Vanessa and Troy. Like most people. she is a lot of everything, and this report covers many of the possibilities.

To disguise the fact that it is injuriously dated, PBS is adding a more recently taped talk between Jane and Henry Fonda to the end of the program. This was not supplied with the copy submitted for review.