By JOHN J. O'CONNOR

Jonathan Miller's version of "Long Day's Journey Into Night," starring Jack Lemmon, began on the stage and had an extensive tour that included limited runs on Broadway and in London. Tonight at 8, it comes to pay cable's Showtime service. This television adaptation has also been directed by Miller. Michael Brandman and Emanuel Azenberg are the executive producers and Iris Merlis the producer of the "Broadway on Showtime" presentation.

The play is, of course, Eugene O'Neill's masterwork, the powerful autobiographical statement of a towering figure in American theater. It is already a fixture in the repertory of world theater and, as such, is a likely candidate for countless interpretations and misinterpretations. Miller, who delights in provocation, created something of a stir by having the characters engage in stretches of overlapping readings of the dialogue. They don't so much interrupt each other as speak simultaneously, apparently in an effort to simulate what Miller deems to be normal conversation and, at the same time, to speed up the action. Even though used sparingly, however, the device quickly becomes an irritating gimmick and the play, despite minor excisions, still runs to just under three hours.

More significant is Miller's passion for natural details, the myriad gestures and intonations that can relate even Shakespeare to everyday life. Lemmon's James Tyrone is the epitome of the ham actor, constantly grunting and groaning to attract attention and always overindicating. When his wife, Mary, says her hair once grew down to her knees, James leans forward to look at her legs. When he remembers something he used to carry in his wallet, James reaches automatically to his now empty back pocket. He is forever busy with the kinds of predictable motions that would undoubtedly shackle an actor who, like James, let his career get trapped in a single, popular stage role.

And Bethel Leslie's Mary never lets us forget that this woman is a drug addict, the passive victim of a quack doctor who prescribed morphine when her youngest son, Edmund, was born. This Mary is edgy and sharp, especially when she thinks her family might prevent her from getting another "fix." The symptoms of her addiction are everywhere, from talking too quickly to trying to avoid looking directly into anyone's eyes. So, too, Edmund, the consumptive son, based on O'Neill himself and played by Peter Gallagher, has a soul-racking cough, and his older brother, Jamie, played by Kevin Spacey, sports an alcohol problem that would be obvious to a passing stranger.

All of which brings the characters perhaps closer to recognizably human terms. But at the same time, the play's tragic impact is diminished. These characters, I believe, are not meant to be part of an everyday world. They are designed to be larger than life. James Tyrone may have evolved into a tired ham actor but he should have enough bombastic grandeur left to impress even his embittered sons. Mary may be a pathetic drug addict, but with her pleading to be returned to the good graces of the Blessed Virgin, she also reflects a far larger tragedy. It is not by chance that when she descends the staircase in the final scene, her heartbroken older son venomously shouts: "The mad scene. Enter Ophelia." Calling on Shakespeare, O'Neill is reaching for considerably more than naturalistic details.

Even scaled down, though, "Long Day's Journey Into Night" remains a special theatrical experience. Its excoriating family confrontations of love and hate, its hairpin emotional turns, its painful dredging of the past to explain the present continue to lure us into O'Neill's demanding and uncompromising universe. This particular production will no doubt continue to trigger debate about the validity of Miller's approach, but it has its assets, not the least of which is watching Lemmon give one of the most ambitious and admirable performances of his career. Showtime and public TV's "American Playhouse" deserve enormous credit for taping this performance of record.