If your best friend is engaged and you think that marriage is not right for him, there's no better gift you can give than "Bartlett's Familiar Quotations." This bible of famous sayings is packed with extracts from the great literature about matrimony, and to no one's surprise the better part of the excerpts is against the institution. In "Don Quixote" Cervantes warns us that "marriage is a noose," while the 16th century essayist, John Selden, counsels that "marriage is a desperate thing." Perhaps these celebrated writers from centuries past know whereof they speak: fully fifty percent of all marriages entered into by Americans end in divorce, and who knows how many others are marred by separation, uncivil warfare, and general misery? "Forces of Nature," a romantic comedy that frequently alerts us to the perils of matrimony but later subverts this discouraging idea, enjoys dependable performances by a reliable cast and some efficient editing that lends extra humor to many of its scenes, but the best thing about the film is Marc Lawrence's screenplay. Loaded with one-liners that range from outright chortles to agreeable chuckles, his script is generally on the level of a first-rate sitcom (think "Cheers"), making the movie a amiable way to spend some time in the company of people who have loved and lost, who have yet to do either, and even some who have retained their affection throughout decades of joyful togetherness.

The story opens on a bachelor party, purportedly the last night of singles freedom for Ben (Ben Affleck), whose gala blast is hosted by his best friend, Alan (Steve Zahn) and given spice by a seductive stripper bedecked in balloons begging to be burst. Ben, armed with non-refundable tickets for his anticipated honeymoon in Hawaii, boards a flight to Savannah, Georgia, where he is to be wed to the wealthy and charming Bridget (Maura Tierney), but when his aircraft veers off the runaway, Ben heads back to the terminal with a fellow passenger, Sarah (Sandra Bullock). As Ben is a conventional sort, he is taken under the wing by this attractive and eccentric woman who is fun-loving where Ben is prosaic, though we later discover that this bundle of joie de vivre has a melancholy side. After a series of adventures together spanning two days, Ben must decide whether to chuck his bride-to-be in favor of this new force of nature, to forget about marriage as an institution for the time being, or to go through with his plans to wed his Georgian debutante.

At once a road movie and a buddy film, "Forces of Nature" takes us through one episode after another, each adding to Ben's exploration of romance. Marc Lawrence is nothing if not canny with one-liners about the nature of marriage. Early on, Ben's granddad--who suffers a heart attack during the young man's bachelor party--confesses that "marriage is a prison," while a male passenger on the flight from New York to Savannah whines about the thirty pounds his wife put on "since we stopped having sex" and bewails the lies he must tell his spouse, such as how she looks so much better than the eighteen-year-old knockout who delivers his paper. When Ben meets a loving elderly couple on a train ride he shares with Sarah, his feelings about marriage become more optimistic--until the duo inform him that "we're not married-- we're having an affair," and the matronly lady describes how until she met this man she had never had an orgasm.

Sitcom that this picture may be, it never fails to entertain thanks to the fortuitous pairing of Ben Affleck, a master at appearing goofy, and Sandra Bullock, a powerhouse of womanly stamina. The chemistry between these opposites is potent, splitting the audience into two groups: those who want Ben to chuck his long-term sweetheart and take up with this fun-loving person, and those who feel he'd be more grounded with the stable person to whom he has declared his love. Supporting actors add zest to the story, particularly Joe (Richard Schiff), a tour guide in a bus to Miami. We wonder until the final minutes whether Ben will follow the advice he comes across in a quote by Oscar Wilde: "One should always be in love--that's why one should never marry." Director Bronwen Hughes, whose innocuous "Harriet the Spy" might have ended her career, has come back with a pleasurable, if TV-level comedy, about two forces of nature--the storm which delays Ben's march to Georgia, and the power of love to conquer all.