BACK TO METHUSELAH - IN THE BEGINNING from Washington Stage Guild. Adam is Brit Herring, Eve is Lynn Steinmetz, Cain is Conrad Feininger. (C. Stanley Photography)

“Life must not cease,” the serpent declares to Adam and Eve in George Bernard Shaw’s “Back to Methuselah.” “That comes before everything.”

That may sound obvious, but Shaw wasn’t so sure Europe believed it during World War I. No wonder he wiped the slate clean to start “Methuselah” with the serpent teaching a wide-eyed Adam and Eve such basic words as “life” and “kill” while marveling at the imaginative possibilities she sees in the first man and woman.

The 28-year-old Washington Stage Guild specializes in early- and mid-20th century European playwrights — stylists and intellectuals, primarily Shaw. It’s a bookish boutique embracing history and big talk (which is a way of saying that design-wise, there’s not much to see here, starting with Brit Herring and founding company member Lynn Steinmetz as the naked-ish Adam and Eve in hoary yellow leotards and strategic tangles of vines).

Even so, the project is a big push for the troupe and pure protein for a niche audience with long attention spans. The rarely staged “Methuselah” is Shaw in a soaring philosophical mode; it’s a five-part cycle so extensive that this 2 1 / 2-hour show only gets through the first two acts.

Act 1, “In the Beginning,” bristles with observations both puckish and harsh about how humankind organizes its business. “You see things, and you say ‘Why?’ But I dream things that never were, and I say ‘Why not?’ ” purrs the serpent in a line that has been long associated with Robert F. Kennedy.

Laura Giannarelli plays the serpent with a wily musical voice as the character painstakingly tutors her innocents in social-political-survival concepts such as will and creation. The Adam and Eve chapter spins ahead a few centuries to the murderous Cain (a defiant Conrad Feininger), whose long, dark, startlingly relevant speeches say a lot about the adrenaline rush of combat and even the selfish lure of industrialism. Why not reap profits while others do the work? That’s just one defiant question he puts to his lame agrarian parents (Herring as a weary Adam, Steinmetz as an increasingly bitter maternal Eve).

Feininger appropriately returns as a blowhard politician in Act 2, “The Gospel of the Family Barnabas,” set closer to our time and with the accents now British. Neatly, Giannarelli also reappears in the second act, this time as a religious scholar. She and her biologist brother make a miraculous claim: For people to really learn anything meaningful and get anything done, they need to live 300 years. And, they declare, it can happen!

The drawing room banter dries up a bit when Shaw lampoons Feininger’s character and another official (a diplomatic Vincent Clark) as the kind of “immature statesmen and monarchs,” as one character says, who wrecked Europe with the war. The actors get stuck in a semicircle, swapping points and barbs without anyone coming away notably wounded or triumphant. For a spell, the show is a flat ride of chatter.

But things brighten with the possibility of living for a few centuries. Is civilization failing? Is longer life — and therefore wiser decision making — the remedy? The quips and speeches begin to sting again, with Michael Avolio dripping disdain as a scientist scoffing at politicians, Nora Palka injecting vitality into the roundtable as a young woman named Savvy, and Giannarelli as a pragmatist happy to shuffle the pols out the door.

A lot of the discussion sounds current, even without director Bill Largess deploying much in the small Undercroft Theatre besides good clean speech to coax Shaw’s ideas our way. Whether mankind can get its act together remains a cliffhanger: The futuristic third and fourth acts of “Methuselah” are on the WSG schedule for next season, with the final part planned for the far-off year of 2016.

Back to Methuselah: In the Beginning and The Gospel of the Family Barnabas

By George Bernard Shaw. Directed by Bill Largess. Set, Shirong Gu; costumes, Basmah Alomar; lighting, Marianne Meadows; sound, Frank DiSalvo Jr. About 2 1 / 2 hours. Through March 16 at the Undercroft Theatre in the Mount Vernon Place United Methodist Church, 900 Massachusetts Ave. NW. Call 240-582-0050 or visit