"Monty Python's The Meaning of Life" sounds jolly, but it quickly falls into facetiousness in the most punishing Python style--elaborate sight gags that grind on interminably, determined to see a grandiose premise through to its bitter end even if it kills a joke and any illusion of spontaneity.

As a matter of fact, "The Meaning of Life" grinds to a halt before the movie proper begins. It amuses the Pythons to pretend that a "short feature" precedes the regular show, a mock swashbuckler called "Crimson Permanent Assurance." In it, elderly galley slaves turn into insurance clerks whose Victorian office building sets sail and attacks a "fleet" of glass skyscrapers, the prize catch being the headquarters of "The Very Big Corporation of America."

The rest of the film consists of farcical sketches on the big loaded questions of existence: Why was I born? Where am I going? What's it all mean, anyway?

The answers, of course, are designed to be cheekily inconclusive or deflating, but there's a mechanical tone of smugness beneath the ridicule. The strongest impressions left by this picture have less to do with its largely tedious attempts to burlesque human weakness and pomposity than with the group's failure to evolve a coherent satiric outlook.

The Pythons have two ingredients: collegiate-wiseguy erudition and compulsive vulgarity; "The Meaning of Life" offers a gross-out mixture of the two. The acid-test sequence is a spectacle of vomiting set in a French restaurant, where Michael Palin as the world's fattest gourmand concludes a gargantuan meal by starting a cycle of upchucking designed to proliferate and accelerate, like the epic custard pie fights or demolition routines of Laurel & Hardy. Well, you reflect, as another cascade of play-vomit hits the floor or one of the performers, this must be the definitive barfing scene. Another milestone fearlessly surpassed, and on to the next pointless offense.

If one looks at the team's chosen targets, it's difficult to find one that hasn't been shot to pieces: insensitive doctors, religious bigots, stuffed-shirt headmasters, unruly schoolboys, oblivious military officers, American tourists, corporation executives, gluttons, headwaiters, TV celebrities. Not exactly a fresh bill of fare.

You can detect some nervous, hypocritical shuffling on certain issues. For example, a skit that starts off joking about a working-class Catholic family so large that dad announces his intention to sell some of the kids for "scientific experiments" veers off into an extravagant dig at right-to-lifers disguised as a parody of the "Consider Yourself at Home" number from "Oliver!" and then detours curiously to accommodate a skit aimed at a sexless Protestant couple. The shifting emphasis suggests nothing so much as a fundamental lack of conviction, which leads to an embarrassed straddle of the "controversial" topic. In addition, director Terry Jones doesn't seem to recognize the contradiction built into the production number: All those beaming, singing and dancing kids add up to a massive contradiction of the anti-breeding bias of their song.

The only skit that amused me for longer than an isolated chortle was the delivery scene, with John Cleese and Graham Chapman playing hardware-happy obstetricians of truly staggering presumption. "We'll soon have you cured," one of them cheerfully informs the poor expectant mother, after wheeling her into the delivery room at breakneck speed. When she timidly asks the sex of her baby, she's reprimanded in haughty terms that strike a note the Pythons could use more of: "I think it's a little early to begin imposing roles on it, don't you?"

As performers, the Pythons can draw on more resources than they seem to as skit writers, but even at this level the well appears to be drying up. The boys spend so much time in drag that I began to wonder if belaboring their British matron caricatures was the only source of fun left to them. "The Meaning of Life" appears to be that the Pythons have run out of fresh communal inspiration. MONTY PYTHON'S THE MEANING OF LIFE

Directed by Terry Jones; written by Graham Chapman, John Cleese, Terry Gilliam, Eric Idle, Terry Jones and Michael Palin; director of animation and special sequence, Terry Gilliam; photographed by Peter Hannan B.S.C.; edited by Julian Doyle; production designer, Harry Lange; choreography, Arlene Phillips; produced by John Goldstone for The Monty Python Partnership. This film is rated R. THE CAST

Graham Chapman, John Cleese, Terry Gilliam, Eric Idle, Terry Jones, Michael Palin