Bill Moyers says his third retirement will be the one that sticks. (Jemal Countess/Getty Images for TIME)

This time, Bill Moyers really means it. After 43 years as public television’s most visible intellectual and its most unabashed liberal, he’s done. As of Friday, he’s officially retiring from TV.

Yes, he’s said that before. Twice, actually. And both times (in 2010 and 2013) he reversed course, returning to TV to pursue his varied passions and crusades — against the corrupting influence of money in politics, for the environment and civil rights, against growing economic inequality — in familiar style, avuncular and Texas-inflected. The last time he retired he was on the sidelines for all of 17 days.

But this time is different, he insists. Moyers, 80, said in a brief note posted on his Web site in September that the final show of his interview series, “Moyers & Co.,” which airs beginning Friday on public stations, would be his last. “I am writing to assure you that this time it’s the real deal,” he wrote then. “. . . It’s time finally to sign off.”

If he does, it will literally be an unceremonious fadeout. As usual, his final program (airing in Washington on Sunday on WHUT, channel 32, and on WETA, channel 26, on Jan. 11) will be a straight-up discussion about a weighty topic, environmental litigation. Moyers isn’t taking any victory laps or indulging in career retrospectives. His Web site doesn’t even mention that he’s leaving television at all.

“Frankly, my third retirement is no big deal and I decided back in September to treat it accordingly,” he said in a series of gracious emails this week. He declined a more formal interview, saying, “If my work doesn’t speak for itself after all these years, I have failed and no amount of interpretation can help.”

Except for stints in commercial broadcasting (CBS News from 1976 to 1986; NBC News briefly in the 1990s), Moyers has been the face of public television for almost as long as Big Bird. He was even there at the creation. As a young aide (and later press secretary) to President Lyndon Johnson in the mid-1960s, Moyers was part of the early planning meetings that led to the passage of the Public Broadcasting Act of 1967, which established PBS and NPR.

Starting in 1971, during President Richard Nixon’s first term, Moyers has produced and hosted innumerable specials, documentaries and series for public television on a bewildering array of topics: American history, religion, philosophy, death, the arts and culture, the news media, the military and politics.

His work has won more than three dozen Emmys — he doesn’t know the precise number — and nine Peabody awards. His personal favorite is a multi-part, multi-Emmy winning series for “Frontline” that followed the economic trajectory of two working-class families in Milwaukee over 22 years. The series, conceived by Moyer’s producer-wife, Judith Davidson Moyers, “nailed what was happening as the middle class dropped through the cracks and the political class looked the other way except rhetorically,” he said.

Moyers himself has attracted as much controversy as awards. His unalloyed liberalism (“I find it very hard to have intelligent conversations with people on the right wing,” he once said) has made him, to conservatives, a living totem of the news media’s alleged leftward bias, and especially public broadcasting’s.

As a “news analyst” who had worked alongside another conservative bête noire, CBS’s Dan Rather, Moyers was already politically suspect when he produced and hosted a 1987 documentary for PBS about the Iran-Contra affair, “The Secret Government.” The program so outraged conservatives that it sparked a new effort to defund the Corporation for Public Broadcasting, the intermediary that funnels federal funds to public broadcasters.

The efforts against Moyers were renewed in 2005 when the conservative chairman of the CPB, Kenneth Tomlinson, sought to demonstrate liberal bias at PBS. Tomlinson secretly commissioned a consultant to monitor the political views of guests on “Now with Bill Moyers.” He ultimately deemed the program “unbalanced” in its discussion of public affairs.

Moyers didn’t back down, firing back that Tomlinson was waging “a surreptitious and relentless campaign” against him, his program and public broadcasting. “I always knew Nixon would be back,” he said at the time. “I just didn’t know that this time he would ask to be chairman of the Corporation for Public Broadcasting.”

In fact, Moyers, an ordained Baptist preacher, has often been an equal-opportunity scold, raining damnation upon both political parties and the mainstream media alike.

“One of our two major parties is dominated by extremists dedicated to destroying the social contract, and the other party has been so enfeebled by two decades of collaboration with the donor class it can offer only feeble resistance to the forces that are devastating everyday people,” he told the Progressive magazine in an interview in February. “Our economy is a plantation run for the aristocrats — the CEOs, hedge funds, private equity firms — while the field hands are left with the scraps.”

Moyers’s take on the news media is only slightly more nuanced. He has irregularly disparaged “the corporate media,” despite receiving paychecks from two large for-profit media organizations for more than a decade. Among other sins, he blames the mainstream news organizations for failing to stop President George W. Bush’s administration from invading Iraq in 2003.

An old friend, broadcaster and columnist Jim Hightower, says he’s long thought Congress should declare Moyers “one of America’s most precious natural resources.” On the other hand, says Hightower, who shares Moyers’s politics and Texas roots, “We tend to clear-cut, strip mine and frack our precious natural resources, so maybe that’s not such a great idea.”

Moyers’ visibility has fallen in recent years, in part because “Moyers & Co.” airs at different times on public stations, sometimes in the wee hours, which complicates national promotion. The program has been distributed not by Arlington, Va.-based PBS but by another outfit, American Public Television, leading to suggestions within public broadcasting that PBS has tried to distance itself from the politically explosive Moyers. PBS spokeswoman Jan McNamara declined direct comment on this, as did Moyers.

Though he will no longer have a television platform, Moyers will continue in the media as an investor. As the longtime president of the New Jersey-based Schumann Center for Media and Democracy (2012 assets: $28.1 million), Moyers has helped direct millions of dollars in charitable grants to left-leaning journals and public broadcasting outlets over the years.

Among the 2012 recipients of Schumann’s largesse: “Democracy Now,” the public-radio program ($750,000); Mother Jones magazine ($200,000); Boston public station WGBH ($25,000); and New York public broadcaster WNET ($140,000). In earlier years, Schuman has supported such liberal outlets as the Nation magazine, the Washington Monthly, In These Times, TomPaine.com, Truthout.org and The American Prospect. Moyers’s dual roles — as both TV host and philanthropist — have sometimes overlapped and even presented possible conflicts of interest.

For example, Schumann helped finance TomPaine.com, which was founded by Moyers’s son John, who was also a former member of Schumann’s board.

Further, in 2011, Schumann gave $859,146 to the Independent Production Fund, according to the foundation’s tax filing. The IPF has produced a number of Moyers’s public television programs over the years.

What’s more, Moyers occasionally featured on his program some of the very organizations Schumann financed without disclosing the connection. In 2012, for example, “Moyers & Co.” devoted an entire episode to an interview with Heather McGhee, the Washington policy director of Demos, a campaign-finance and advocacy organization. Schumann gave $375,000 to Demos in 2012 and 2011, the last years public records are available.

Asked repeatedly about this, Moyers offered no response.

At the very least, Moyers’s politics have been consistent throughout his long career. He may be retiring, but he waves off suggestions that he’s mellowing. Asked if by the Progressive last year if he had become even more liberal with time, Moyers said this:

“I’ve lived long enough to see the triumph of zealots and absolutists, to watch money swallow politics, to witness the rise of the corporate state. I didn’t drift. I moved left just by standing still.”