Ettore Scola's "Down and Dirty," opening today at the West End Circle, is the most audacious and compelling comedy of social depravity since Bertrand Blier's "Going Places." Scola has done for the hardcore, undeserving poor what Blier did for ignorant, rapacious youth.

Although the original Italian title, "Brutti, sporchi e cattivi," would be more accurate - "Ugly, Filthy and Rotten" - Scola and his co-writer, Ruggero Maccari, must have intended humorous echoes of Sergio Leone's "The Godd, the Bad and the Ugly" ("Il buonno, il brutto, il cattivo").

For its content, the film might be called "Tobacco Road Italian Style." Giacinto, the protagonist, is a poor white-trash patriarch relocated in the city, where he sinks into a dissipated old age while lording it over the teeming family around him a a shanty-town dump.

Nino Manfredi, whose performances as the hard-luck movie nut in Scola's "We All Loved Each Other So Much" and the persevering Italian laborer in Franco Brusati's "Bread and Chocolate" have made him a local art-house favorite, enhances his reputation in the blatantly disreputable role of Giacinto.

Manfredi endows this selfish old wretch with a kind of besotted animal cunning and stamina. He navigates in such a fog of overindulged base appetites that you're convinced he's capable of evert oblivious comic outrage - like blithely forgetting a beating recently administrated to his grosssssss, seething wife (Maria Bosco adorned with scraggly facial hair) or going on a rampage when he can't find the million lira stash he's always hiding around the hovel.

Despsite the appearance of always being a step from falling flat on his grizzled face, Giacinto is no push-over, ashis scheming loved ones discover when they try to murder him for his money, an insurance pay-off for his eye injury.

Clingiing tenaciously to his misspent life, Giacinto pproves too mean to croak, although in one of his wilder inspirations, Manfredi assumes a stricken position resembling a dying rat. He tops this moments later when Giacinto rouses himself and escapes the murder scene, a family picnic, on a bicycle. He falls, but ruled by that stubborn will to live, keeps pedaling while prone.

Scola begins this ironic, harmoniously stylized satire with a witty series of 360-degree pans set aside Giacinto's residence at daybreak. The camera records images of countless slumbering bodies crowded into an irregular one-room rectangle, whose furnishings range from recycled junk to brand-new appliances, and presently discovers a form moving in the gloom, stealthily searching the premises.

The search comes to a sudden end in an alcove where Giacinto, the master of the house, is awake, alert and pleased to be pointing a shotgun at the head of the searcher. Another typical day has begun: Just as he suspected, another one of his dependents has tried to steal his bundle again. As always, he's been too smart for them.

Snarling what becomes a patriarchal refrain, "I'll kick 'em all out; if not today, tomorrow," Giacinto triumphantly reveals where he really kept the coveted treasure. This ritual completed, the other family members roll out of bed to begin a fresh sound of menial chores, squabbling, scrounging, conspiring and hanging around.

In addition to Gascinto and Gaetana, his obese, hirsute, long-suffering mate, the household, situated on a hilltop dumpsite overlooking relatively new apartment complexes, consists of a reputed dozen children (more or less adult), an indeterminate number of grandchildren, in-laws and a wizened granny addicted to television. Giacinto's insurance money allows him to pose as a man of leisure while he habitually complains about the alleged selfishness of his off-srping. "If you want money," he grumbles, "poke out your own eye."

Given this sort of parental encouragement and their nearly subterranean social status, it's all too easy for the boys to drift into petty theft and the girls into prostitution. Like Blier, Scola doesn't take a moralistic or sentimental view of the deplorable behavior he depicits. Scola seems to be saying that people and social conditions may be improvable, but depravity has staying power.

"Down and Dirty" confirms Scola's talent, already abundantly enjoyable in "The Pizza Triangle" and "We All Loved Each Other So Much," for combining raucous, uninhibited comedy with social documentation and criticism. Choosing the incorrigible poor for social satire, he risks being automatically reviled for offending good taste and progressive sentiment. He also makes it more difficult to satisfactorily blend comic storytelling with serious implications.

To his credit and our advantage, the blend works again and seems even more savory by virtue of the narrow margin for error. "Down and Dirty" is not an uncaring view of urban squalor. Scola probably cares as much as Vittorio De Sica did when he made the sublimely evasive lyrical comedy about down-and-outers, "Miracle in Milan," or Akira Kurosawa did when he made the foolishly sentimental "Dodeskaden," a veritable love to demented down-and-outers.

Scola isn't at his best wearing his heart on his sleeve, a mistake he made in the dreary "A Special Day" with Sophia Loren and Marcello Mastroianni. He seems to care most authentically and see most clearly through a comic perspective. "Down and Dirty" revives that perspective with delightful and powerful clarity. CAPTION: Picture, Nino Manfredi (seated, top center) with his mistress Maria Luisa Santella (left) and wife Maria Bosco (right) in "Down and Dirty."