''The Golden Age'' offers the rewards of a stylish comedy that is stylishly acted and is imbued with a humanity that shines through its style. According to A.R. Gurney Jr., his play was suggested by Henry James's ''The Aspern Papers.'' (In 1959, Michael Redgrave appeared in his own adaptation of the novelette. The play is now being revived in London.) While Mr. Gurney has borrowed the basic premise of the tale, he has changed the mood, advanced the action to the present, and transplanted the scene from Venice to an Upper East Side New York brownstone.
Into the seclusion of this elegant retreat bursts Tom (Jeff Daniels), a kind of literary Lochinvar out of the Midwest. Tom is bent on unveiling the closely guarded secrets of Isabel Hastings Hoyt (Irene Worth), once the darling of the 1920s literary set, whose retirement may or may not be as gilded as it seems. Mrs. Hoyt's only companion is her dowdy, twice-divorced granddaughter, Virginia (Stockard Channing), who solaces herself with alcohol and befriends stray cats.
''The Golden Age'' wears its rue with a high-comedy difference. Mr. Gurney delights in the irrepressible playfulness with which Mrs. Hoyt taunts and teases the interloper she dubs ''Tom, Tom, the piper's son.'' The dowager intends to profit handsomely from whatever morsels of gossip and genuine literary history she deigns to disclose. The choicest item is a rumored missing chapter from ''The Great Gatsby,'' a treasure retained from her perhaps intimate friendship with F. Scott Fitzgerald. Besides stage-managing the collaboration, Mrs. Hoyt is determined to dictate its terms (including hardcover publication). She envisions the potential profits from the memoir as a legacy for Virginia, and Tom as the young woman's husband and protector. Of course, nothing works out according to anybody's plans. But in the course of the negotiations, maneuvers, and near betrayals, Virginia is transformed. Her emergence from self-doubting diffidence to confident self-identity becomes the focal point of ''The Golden Age.''
Under John Tillinger's fine-tuned direction, the cast responds with resource and relish to the Gurney comic style. Miss Worth is a paragon of humorous patricianism. Her name-dropping ranges from Freud, Jung, and Picasso, to Porter, Eliot, and Eleanor Roosevelt. She can be arrogant, outrageous, eccentric, charming, and whimsical. ''I feel,'' says Isabel at one point, ''like a little bit of fluff out of Booth Tarkington.'' Some fluff!
As Tom, Mr. Daniels creates the persuasive portrait of a young man whose obsession is more than mere opportunism and whose determination to score a literary coup is not entirely without decent scruples. Miss Channing's Virginia, the bruised descendant of a not-so-golden age, invests the granddaughter with a comic self-pity and susceptibility balanced by a survivor's clear-sighted realism. By the play's end, Virginia has earned her liberation.
The handsomely appointed production features a brownstone interior setting in the impeccable Oliver Smith manner, Jane Greenwood costumes that help define the identities of the wearers, and mellow lighting by Arden Fingerhut. For incidental music, such golden oldies as ''You Took Advantage of Me'' and ''Poor Butterfly'' add their own strains of irony and nostalgia to a civilized comedy of manners and intelligent reflections. ''The Golden Age'' has reopened the renamed and refurbished Jack Lawrence Theatre on West 48th Street.