The setting is forbidding, the political parable heavy-handed and human nature “inevitable” in “Eden,” Ron Howard’s dip into real history for a sociology lesson that can apply to today.

It’s an all-star rendering of a true story of Germans who tried to experience a new way to live on a tropical island — Floreana in the  Galápagos Archipelago — during the Great Depression.

Despite having “It” girls Ana de Armas, Sydney Sweeney and Vanessa Kirby in the cast with Jude Law and Daniel Brühl, the Oscar-winning Howard found himself with a difficult-to-market survival tale, a movie possibly tainted by its reception at a Toronto Film Festival premiere, one that virtually no one wanted to distribute.

But the picture reaching theaters is a solid yarn, a well-acted and suspenseful thriller that covers well-worn “Lord of the Flies” ground about ugly features of human psychology that show up when “society” doesn’t smooth out the rough spots.

After the horrors of World War I, a Spanish Flu pandemic and with the Great Depression finishing off the Roaring Twenties, the philosphy-obsessed German physician Friedrich Ritter (Law) and his life partner, Dore Strauch (Kirby) set off to uninhabited Floreana Island to live simply and escape from society to a place where the Nietzsche-adoring Ritter could formulate a “new” philosophy that could save humanity from the doom he saw awaiting it.

He’s German. He’s seen what happened there and what’s brewing in the poisonous politics of the present. And given the second World War we all know is coming, he wasn’t wrong.

He sends letters talking up his philosophy and their contemplative vegetarian lives there which get published in newspapers and create an allure in “a world that’s gone crazy.” Maybe one can “get away from it all.” But whatever the purpose of his letters, he draws fans. “Eden” is about what happens when a family of them move to join them on the semi-arid volcanic rock they’re living on.

Heinz Wittmer (Brühl) is, Ritter decides, “a man broken by the war.” Scarred, widowed and recently remarried, Wittmer quit a civil service job, sold most of their possessions and brought young bride Margret (Sweeney), his tubercular teen son Harry (Jonathan Tittel) and their dog, along with supplies and tools, to live on the island near their idol.

Grumpy Ritter, resenting the distraction, directs them to one of the two tiny springs on Floreana, encourages them to set up housekeeping there and waits for them to fail.

“Life here is gruesome,” he warns them as he smirks to Dore, whom he’s claimed to “cure” of her multiple sclerosis in his letters. “Failure is inevitable!” As inevitable as the coming cataclysm back home, he figures.

But while the Wittmers may not be intellectuals, conjuring up a philosophy that will “save” the human race, they are prototypical pragmatists. With Harry getting some of his strength back in the hot, dry climate, Heinz’s muscle and Margret’s stoic practicality, they set up house and home and garden, tame a wild cow (left behind, like the wild pigs, wild dogs and Dore’s “pet” donkey, by passing sailors over the years) and do all this in a fraction of the time that the distracted intelligentsia managed it.

Ritter is barely adjusting to the fact that their failiure isn’t “inevitable” and that they may not take his “I’m no longer a DOCTOR” barks seriously when Margret gets pregnant when a boatload of other fans show up.

Baroness Eloise Bosquet de Wagner Wehrhorn (de Armas) is a flamboyant bon vivant with grandiose dreams of a “Hacienda Paradiso,” “the world’s most exclusive resort hotel,” which she will build on this “Eden” that the exaggerating doctor described in his published letters.

She’s got a South American “engineer” (Ignacio Gasparin) to help her start construction, and two lovers/helpmates (Felix Kammerer and Toby Wallace) to provide the well-digging, foundation-laying muscle.

Fat chance of that. They’ve been dropped off with a vast array of her luggage, lots of alcohol and canned goods, tents and a Victrola. But the good doctor pitched this place as a perfect setting for the “grandiose.” Maybe they’ll fit right in.

The baroness is arrogant, privileged, rude and manipulative. And those aides and “bodyguards?” We and the locals notice they’re wearing sidearms.

Let the “Lords” start lording over the “flies” and let’s see where this takes us.

This true story, complete with scandal, violence and political and social allegories built in, has been a part of popular culture — books, articles — in the decades since it happened. It could have inspired such film narratives as “Swept Away,” and it was the subject of a broadly-distributed 2013 documentary, “The Galapagos Affair.”

Howard and screenwriter Noah Pink (“Tetris”) set up a simplistic dynamic made for conflict, and let it play out accordingly. Stealing food and trying to set rivals against each other in a forbidding place with little survivable margin for error ensures that there will be blood. But whose?

The script and Howard, pursuing one last “dream project,” attracted a stellar cast and they do not disappoint. Law gives a fanatical edge to his dreamer. Kirby’s flintiness is channeled into an embittered, brilliant beauty, de Armas vamps and schemes and has never been more hateful and Brühl perfectly captures a pacifistic Everyman faced with neighbors who could cripple his family’s odds for survival.

And while this isn’t the movie that “made” Sweeney’s big screen career, it is her most impressive performance outside of TV’s “Euphoria.” She embodies the shrinking violet “hausfrau” who is no competition for the more vivacious, sexy and cunning other women on the island. Sweeney lets us see Margret’s pragmatism in her realization that everyone needs to get along. But while she may be steely enough to face childbirth amidst a wild dog attack (Whoa) alone, she is slow to figure out her trust in the doctor, Dore or the baroness is misguided.

Margret and to a lesser degree Heinz embody one message in all of this, that defaulting to kindness and mediating conflict is the way society should function. But the other lesson for life today here is the harder one to swallow.

There is no escaping fascism and the cruel creeps who embrace it. The utopian doctor may dream of “true democracy” inspired by a new philosophy. But the way of human civilization is “Democracy, fascism and then war,” he preaches. “It is INEVITABLE!”

That World War they all lived through wasn’t “humanity at its worst.” It was “humanity at its truest.”

“Eden” isn’t the subtlest allegory about life in troubled times, but Howard rarely makes a bad film and he hasn’t here. From its eyes-averting grimness to its eye-rolling obviousness and “inevitability, “Eden” is a parable that plays.

And whatever the box office prospects, nobody in this cast should run away from this resume credit. There isn’t a false note among them.

Rating: R, graphic violence, sex, nudity and profanity

Cast: Jude Law, Sydney Sweeney, Ana de Armas,
Daniel Brühl, Felix Kammerer, Ignacio Gasparin, Toby Wallace, Jonathan Tittel and Vanessa Kirby.

Credits: Directed by Ron Howard, scripted by Noah Pink. A Vertical release.

Running time: 2″09