His fans and critics fill the soundtrack of the documentary, “We Are As Gods” with cogent descriptions of philosopher, “visionary,” activist and Big Idea cheerleader Stewart Brand. He is an “intellectual Johnny Appleseed of the Counter Culture,” a “P.T. Barnum” huckster, the “Zelig of cyber culture,” and more to the point — a “Forrest Gump” figure whose “superpower” was his “eerie” ability to see The Next Big Thing and be there to inspire, guide and champion it.

The film is a celebration of the most optimistic big thinker of them all, a figure who has been at the forefront of many of the best phenomena, trends, technology and values inculcated in modern culture.

The environmental movement was on low simmer until Brand led a nationwide campaign to get NASA to take a photograph of the entire Earth, the “blue marble” floating in the void. It was an image that shifted thinking about world worth protecting and saving. Brand’s “Whole Earth Catalog” quarterly gave the ensuing movement focus, momentum and “tools” for living. The book is cited by Steve Jobs and The Woz and many an internet start-up as being a guidepost for their endeavors and desire to think forward and plan big.

Brand was in on the ground floor of “hacker culture,” helping to characterize “the personal computer revolution” and the thinkers and doers who have been driving it.

“You have an idea. And it still seems like a good idea the next day, you get started” has been his golden rule.

And if you’ve heard of efforts to use preserved and recreated DNA to bring wooly mammoths, American chestnuts and passenger pigeons back to life, it’s probably because of Brand, pushing an idea that could be either a “part of the solution” to our climate change crisis, or a distraction from saving nature and making big decisions about carbon-based energy that grow more pressing by the day, as his critics say.

“We Are As Gods” takes its title from a line that opened “The Whole Earth Catalog” — “We are as gods. So we might as well get good at it.” During its brief run of publication — 1968-1971 — “The Whole Earth Catalog” literally shifted global culture, producing revolutions in human thinking about the environment, technology and human-interconnectedness. Though it has its against-the-grain critics, more than one publication over the decades has called it “the book that changed the world.”

David Alvarado and Jason Sussberg track the wizened, ever-smiling Brand as he thinks, travels, encourages, engages in debates (which he sometimes loses) about his latest big notion — “de-extinction.” They follow him to Siberia’s Pleistocene Park, which hopes to recreate natural conditions that existed there pre-human civilization, a frozen tundra with many large mammal species grazing, pushing back forests and creating “The Wooly Mammoth Steppes” of the ancient past.

One of the animals that the founder, Sergey Zimov, hopes will be a re-introduced is a genetically-revived wooly mammoth population, the “keystone species” of such a steppe. That will take a “moon shot” or “Manhattan Project” level effort. But bits and pieces of it are coming together.

Brand oversees efforts to bring back the functionally extinct American chestnut, killed by an invasive fungus in the early years of the twentieth century. This initiative has reached the stage where genetically modified, Asian fungus resistant chestnuts are being reintroduced into nature, with the idea of returning another “keystone species” to North America.

The chestnuts’ die-off destroyed a whole eco-system, an exclamation point on the deforestation of the eastern U.S. Brand shows the filmmakers carefully-preserved specimens of the passenger pigeon, a natural wonder that once covered North America in flocks so vas they blacked out the sun. Habitat destruction imperiled them. And then they were hunted to extinction.

The film serves as a memoir, revisiting Brand’s childhood and college days — his Stanford mentor was Paul Ehrlich, the self-described population “doom-sayer,” the perfect pessimist to Brand’s brand of “Let’s see if we can fix this” sunniness.

There’s a whole section of push-back against Brand’s “hubris,” the tinkering with nature when humanity has already done so much to foul things up. That keeps “We Are As Gods” from becoming a simple hagiography.

Brand has had his doubts, his bouts with addiction and depression, and an abandoned marriage. He “killed success” when he pulled the plug on “The Whole Earth Catalog” just as it was reaching its peak.

But as we hear from scores of figures, from the late Steve Jobs of Apple to astronaut Russell Schweikart, geneticist George Church to many others inspired by, given a name for their “movement” and a sense of direction by Brand, it’s hard to wholly embrace the fears of “genetically engineered” this or that.

Brand, “an evangelical optimist,” has given this stuff a lot of thought. And much of the bad that’s happened comes from ignoring or taking up opposition to the counter-culture he’s espoused since his days as a Ken Kesey “merry prankster” and proto-environmentalist.

He’s always been ahead of the curve. Maybe we should listen to the guy who ended each edition of his most famous creation with the plea, “Stay hungry. Stay foolish.” He’s in the business of firing imaginations and synthesizing the zeitgeist. And if he thinks a race that can bring back the wooly mammoth and passenger pigeon would take take those scientific wonders as cues to Think Big and Be Bold in saving the planet, he might be right. Again.

Rating: unrated, drug abuse discussions

Cast: Stewart Brand, Paul Ehrlich, Lynn Rothschild, George Church, Hunter Lovins, Russell Schweickart, Lois Jennings, Sergey Zimov, Brian Eno, Peter Coyote and Kevin Kelly.

Credits: Scripted and directed by David Alvarado and Jason Sussberg. A Greenwich Entertainment release.

Running time: 1:34