Effective almost in spite of itself, "Whose Life Is It Anyway?" illustrates how a piece of material can work in a self-contradictory way.While the thesis insists that life may not be worth living in the face of certain hardships, the human environment suggests far more persuasively that life is worth living, perhaps even more so in the face of exceptional hardship. Because the story is resolved on a poignantly equivocal note, there's even more reason to believe that the formal argument has been undermined by deep-seated life-affirming sentiments.

"Whose Life Is It Anyway?" (a terrible, glib title) originated as a British television play in 1972. It was the first professional production written by Brian Clark, then a drama instructor at the University of Hull. Clark adapted it successfully to the London stage in 1978, and the success was duplicated a year later on Broadway, with Tom Conti recreating his performance as the protagonist, Ken Harrison, a sculptor paralyzed from the neck down by spinal injuries suffered in a car accident.

The movie version, opening today at the Avalon 1, transposes the story to Boston and adds a few scenes, none of them crucial enhancements or liabilities to the theatrical text. It's a crisp, attractive production. Director John Badham and production designer Gene Callahan would appear to enjoy several pictorial advantages over their theatrical counterparts. For example, they can exploit both the realistic and suggestive possibilities of an elaborate hospital set, a ward full of transparent, glassed-in cubicles and modern electronic monitoring devices, particularly TV cameras which keep the patients under constant surveillance at a central console. The movie setting seems equipped to underscore the condition of utter physical dependence.

At the same time, this hi-tech hospital environment is populated by a lively, sympathetic staff. There's no attempt to suggest that humane treatment has been a casualty of modernization. The place looks streamlined, but it's not impersonal.

The movie's ace-in-the-hole is certainly this illusion of bustling, friendly human interplay, enthusiastically enacted by an expert, amusing cast. The key piece of casting -- Richard Dreyfuss as the quadriplegic hero -- suggests an acting stunt, of course. Can our most energized young movie actor get away with the impersonation of a character denied mobility? He can, and better than I imagined. Dreyfuss' face and voice prove sufficiently expressive instruments to do justice to the pride and frustration that supposedly drive Ken to the point of preferring to terminate his life.

Ken's first wisecracking exchanges with the amiable supervising nurse, Rodriguez, played by Alba Oms, and the endearing, nervous student nurse, Sadler, played by Kaki Hunter (the delightful, snaggletoothed comic ingenue from "Roadie"), display a familiar heroic gallantry -- gallows humor as a response to a catastrophic condition. Introduced to Sadler, he quips, "I'm afraid I can't offer you my hand. You'll just have to make do with my backside like all the other nurses."

Ken appears to share an easy rapport with almost everyone who checks in -- Thomas Carter as the West Indian orderly John; the towering Christine Lahti as his doctor, Clare Scott; Janet Eilber as his fiance', a willowy ballerina named Pat, a character added by the filmmakers. Nevertheless, the humorous, self-deprecating banter is meant to be deceptive -- a fragile defense mechanism which ultimately proves no defense against a suicidal resolve.

Ken's sense of antagonism is concentrated on a single member of the staff -- John Cassavetes as the supervising physician, Dr. Michael Emerson, whose dedication to preserving life is perceived as slightly fanatic and perhaps insensitive to the feelings of patients as badly disabled as Ken. The antagonism always sounds basically trumped-up for the sake of the eventual dramatic debate, which obliges a kindly judge played by the always welcome Kenneth McMillan to rule on the question, "does a patient have a right to refuse the hospital care necessary to keep him alive?" When Dreyfuss and Cassavetes appear together, one feels an underlying rapport that also contradicts the superficial antagonism. You're never convinced that a meeting of the minds is impossible between these two men, that they really embody irreconcilable outlooks.

In a similar respect, Ken's stated reason for wanting to turn off the life-support equipment seems dubiously contrived. He's supposed to be haunted by the thought of never being able to practice his art again. The loss of the tactile sensations and manipulations associated with sculpting seems unbearable, provoking him to argue, "I cannot believe this condition constitutes life in any recognizable form."

It's much easier to believe that Ken would be driven to despair by damaged masculine pride. There are two harrowing sequences illustrating the helplessness bound to threaten and haunt him -- a moment when Nurse Sadler loses hold of him and he slips headfirst toward the floor and another moment when he begins to choke. These experiences seem more vividly discouraging than the presumed loss of his artistic capacity. Brooding about them might indeed make suicide appear a welcome deliverance from lifelong disability.

On the other hand, they might just as easily provoke a renewed commitment to survival. Thematically, "Whose Life Is It Anyway?" attempts to demonstrate that Ken is to be admired for choosing death as a rational, preferable alternative in his extremely specialized case. The irony is that this theme probably defies convincing dramatization even in an extremely specialized case. It's the life force that predominates in "Whose Life," if only in "incidental" human exchanges. As a result, we're left with a curiously appealing, self-deceiving tearjerker -- a topical update that seems loath to admit that it remains a traditional, inspirational tearjerker.