Updated: April 5, 2013 12:38PM

Roger Ebert loved movies.

Except for those he hated.

For a film with a daring director, a talented cast, a captivating plot or, ideally, all three, there could be no better advocate than Roger Ebert, who passionately celebrated and promoted excellence in film while deflating the awful, the derivative or the merely mediocre with an observant eye, a sharp wit and a depth of knowledge that delighted his millions of readers and viewers.

“No good film is too long,” he once wrote, a sentiment he felt strongly enough about to have engraved on pens. “No bad movie is short enough.”

Ebert, 70, who reviewed movies for the Chicago Sun-Times for 46 years and on TV for 31 years, and who was without question the nation’s most prominent and influential film critic, died Thursday in Chicago.

“We were getting ready to go home today for hospice care, when he looked at us, smiled, and passed away,” said his wife, Chaz Ebert. “No struggle, no pain, just a quiet, dignified transition.”

He had been in poor health over the past decade, battling cancers of the thyroid and salivary gland.

He lost part of his lower jaw in 2006, and with it the ability to speak or eat, a calamity that would have driven other men from the public eye. But Ebert refused to hide, instead forging what became a new chapter in his career, an extraordinary chronicle of his devastating illness that won him a new generation of admirers. “No point in denying it,” he wrote, analyzing his medical struggles with characteristic courage, candor and wit, a view that was never tinged with bitterness or self-pity.

On Tuesday, Ebert blogged that he had suffered a recurrence of cancer following a hip fracture suffered in December and would be taking “a leave of presence.” In the blog essay, marking his 46th anniversary of becoming the Sun-Times film critic, Ebert wrote “I am not going away. My intent is to continue to write selected reviews but to leave the rest to a talented team of writers hand-picked and greatly admired by me.”

Always technically savvy — he was an early investor in Google — Ebert let the Internet be his voice. His site, rogerebert.com, had millions of fans, and he received a special achievement award as the 2010 “Person of the Year” from the Webby Awards, which noted that “his online journal has raised the bar for the level of poignancy, thoughtfulness and critique one can achieve on the Web.” His Twitter feed had more than 841,000 followers.

Ebert was both widely popular and professionally respected. He not only won a Pulitzer Prize — the first film critic to do so — but his name was added to the Hollywood Walk of Fame in 2005, among the movie stars he wrote about so well for so long. His reviews were syndicated in hundreds of newspapers worldwide.

The same year Ebert won the Pulitzer — 1975 — he also launched a new kind of television program: “Opening Soon at a Theater Near You” with Chicago Tribune movie critic Gene Siskel on WTTW-Channel 11. At first it ran monthly.

The combination worked. The trim, balding Siskel perfectly balanced the bespectacled, portly Ebert. In 1978, the show, retitled “Sneak Previews,” moved to PBS for national distribution, and the duo was on its way to becoming a fixture in American culture.

“Tall and thin, short and fat. Laurel and Hardy,” Ebert once wrote. “We were parodied on ‘SNL’ and by Bob Hope and Danny Thomas and, the ultimate honor, in the pages of Mad magazine.”

His colleagues admired him as a workhorse. Ebert reviewed as many as 306 movies a year, after he grew ill scheduling his cancer surgeries around the release of important pictures. He eagerly contributed to other sections of the paper — interviews with and obituaries of movie stars, even political columns on issues he cared strongly about on the editorial pages.

In 1997, dissatisfied with spending his critical powers “locked in the present,” he began a running a feature revisiting classic movies and eventually published three books on “The Great Movies” (and two books on movies he hated). A second column, his “Movie Answer Man,” allowed readers to learn about intriguing details of cinema that only a Roger Ebert knew or could ferret out.

That, too, became a book. Ebert wrote more books than any TV personality since Steve Allen — 17 in all. Not only collections of reviews, both good and bad, and critiques of great movies, but humorous glossaries and even a novel, “Behind the Phantom’s Mask,” that was serialized in the Sun-Times. He even wrote a book about rice cookers, “The Pot and How to Use It,” despite the fact that he could no longer eat. In 2011, his autobiography, “Life Itself,” won rave reviews. “This is the best thing Mr. Ebert has ever written,” Janet Maslin wrote in the New York Times. It is, fittingly enough, being made into a documentary, produced by his longtime friend, Martin Scor­sese.

Roger Joseph Ebert was born in Urbana on June 18, 1942, the son of Walter and Annabel Ebert. His father was an electrician at the University of Illinois, his mother, a bookkeeper. It was a liberal household — Ebert remembers his parents praying for the success of Harry Truman in the election of 1948. As a child, he published a mimeographed neighborhood newspaper and a stamp collectors’ newspaper in elementary school.

In high school, he was, as he later wrote, “demented in [his] zeal for school activities,” joining the swim team, acting in plays, founding the Science Fiction Club, co-hosting Urbana High School’s Saturday morning radio program, co-editing the newspaper, being elected senior class president.

He began his professional writing career at 15, as a sportswriter covering the high school beat for the News-Gazette in Champaign-Urbana.

Ebert went on to the University of Illinois, where he published a weekly journal of politics and opinion as a freshman and served as editor of the Daily Illini his senior year. He graduated in 1964 and studied in South Africa on a Rotary Scholarship.

While still in Urbana, he began free-lancing for the Sun-Times and the Chicago Daily News.

He was accepted at the University of Chicago, where he planned to earn his doctorate in English (an avid reader, Ebert later used literary authors to help explain films — for example, quoting e.e. cummings several times in his review of Stanley Kubrick’s groundbreaking “2001: A Space Odyssey.”)

But Ebert also had written to Herman Kogan, for whom he free-lanced at the Daily News, asking for a job, and ended up at the Sun-Times in September 1966, working part time. The following April, he was asked to become the newspaper’s film critic when the previous critic, Eleanor Keen, retired.

“I didn’t know the job was open until the day I was given it,” Ebert later said. “I had no idea. Bob Zonka, the features editor, called me into the conference room and said, ‘We’re gonna make you the movie critic.’ It fell out of the sky.”

Ebert’s goal up to that point had been to be “a columnist like Royko,” but he accepted this new stroke of luck, which came at exactly the right time. Movie criticism had been a backwater of journalism, barely more than recounting the plots and stars of movies — the Tribune ran its reviews under a jokey generic byline, “Mae Tinee.” But American cinema was about to enter a period of unprecedented creativity, and criticism would follow along. Restrictive film standards were finally easing up, in part thanks to his efforts. When Ebert began reviewing movies, Chicago still had an official film board that often banned daring movies here — Lynn Redgrave’s “Georgy Girl” was kept off Chicago screens in 1966 — and Ebert immediately began lobbying for elimination of the censorship board.

He had a good eye. His Sept. 25, 1967, review of Warren Beatty and Faye Dunaway in “Bonnie and Clyde” called the movie “a milestone” and “a landmark.”

“Years from now it is quite possible that ‘Bonnie and Clyde’ will be seen as the definitive film of the 1960s,” he wrote, “showing with sadness, humor and unforgiving detail what one society had come to.”

It was. Though of course Ebert was not infallible — while giving Mike Nichols’ “The Graduate” four stars in the same year, he added that the movie’s “only flaw, I believe, is the introduction of limp, wordy Simon and Garfunkel songs.’’

Ebert plunged into what turned out to be a mini-golden age of Chicago journalism. He found himself befriended by Mike Royko — with whom he wrote an unproduced screenplay. He drank with Royko, and with Nelson Algren and Studs Terkel. He wrote a trashy Hollywood movie, “Beyond the Valley of the Dolls,’’ for Russ Meyer, having met the king of the buxom B-movie after writing an appreciation of his work.

In later years, Ebert was alternately sheepish and proud of the movie. It was the first “sexploitation” film by a major studio, 20th Century Fox, though Time magazine’s Richard Corliss did call it one of the 10 best films of the 1970s.

It was not Ebert’s only foray into film writing — he was also hired to write a movie for the Sex Pistols, the seminal British punk band in the late 1970s.

Eventually, Sun-Times editor James Hoge demanded that Ebert — who took a leave of absence when he went to Hollywood to write “Beyond the Valley of the Dolls” — decide between making films and reviewing them. He chose newspapering, which increasingly became known because of his TV fame, which grew around his complex partnership with Gene Siskel on “Sneak Previews.”

“At first the relationship on TV was edgy and uncomfortable,” Ebert wrote in 1999, after Siskel’s untimely death, at 53. “Our newspaper rivalry was always in the air between us. Gene liked to tell about the time he was taking a nap under a conference table at the television station, overheard a telephone conversation I was having with an editor, and scooped me on the story.”

In 1981, the program was renamed “At the Movies” and moved to Tribune Broadcasting. In 1986, it became “Siskel & Ebert & The Movies” and moved to Buena Vista Television, and the duo began the signature “thumbs up, thumbs down” rating system that Ebert invented.

“When we left to go with Disney . . . we had to change some things because we were afraid of [violating] intellectual property rights,’’ he said. “And I came up with the idea of giving thumbs up and thumbs down. And the reason that Siskel and I were able to trademark that is that the phrase ‘two thumbs up’ in connection with movies had never been used. And in fact, the phrase ‘two thumbs up’ was not in the vernacular. And now, of course, it’s part of the language.”

“Two thumbs up” became their registered trademark and a highly coveted endorsement that inevitably ran at the top of movie advertisements.

After Siskel died in 1999, Ebert auditioned a number of temporary co-hosts and settled on Sun-Times colleague Richard Roeper in 2000. At its height, “Ebert & Roeper,” was seen on 200 stations.

“Everyone keeps asking me for my favorite Roger Ebert story, or the one thing about him most people might not have known. Here’s the thing: Roger Ebert has already told all the best Roger Ebert stories in far better fashion than I ever could,” said Roeper, who continued the show after health troubles forced Ebert from the airwaves in 2006, until both men quit in 2008 after a contract dispute.

“And whether you ‘knew’ him only through his reviews or his Twitter feed or his blog, or you were lucky enough to have been his friend for many years, with Roger, what you saw and heard was the 100 percent, unvarnished, real deal,” Roeper said. “There was no ‘off camera’ Roger. He was just as passionate, smart, stubborn, genuine and funny behind the scenes as he was in the public eye. He was a great writer and an even better friend.

“They can remake movies, but no one will ever be able to recreate or match the one and only Roger Ebert.”

All that need be mentioned of Ebert’s social life was that in the early 1980s he briefly went out with the hostess of a modest local TV show called “AM Chicago.” Taking her to the Hamburger Hamlet for dinner, Ebert suggested that she syndicate her show, using his success with Siskel as an example of the kind of riches that awaited. While she didn’t return his romantic interest, Oprah Winfrey did follow his business advice.

In his memoir, Ebert writes of a controlling, alcoholic, faith-obsessed mother whom he was frightened of displeasing. “I would never marry before my mother died,” he wrote. She died in 1987, and in 1992 he got married, for the first time, at age 50, to attorney Chaz Hammel-Smith (later Chaz Hammelsmith), who was the great romance of his life and his rock in sickness, instrumental in helping Ebert continue his workload as his health declined.

“She fills my horizon, she is the great fact of my life, she is the love of my life, she saved me from the fate of living out my life alone,” he wrote.

In addition to his TV and newspaper work, Ebert was a fixture at film festivals around the world — Toronto, Cannes, Telluride — and even created a festival of his own, The Overlooked Film Festival, or just “Ebertfest,” which he began in Champaign in 1999 and dedicated to highlighting neglected classics.

Between 1970 and 2010, Ebert made yearly visits to the University of Colorado’s springtime Conference on World Affairs, where he has presented frame-by-frame critiques of classic movies to enraptured audiences.

He had also used the conference to speak on a variety of subjects, from his romantic life to his recovery from alcoholism — he stopped drinking in 1979 — to the problem of spam email. In 1996, Ebert coined the “Boulder Pledge,” considered a cornerstone in the battle against spam.

“Under no circumstances will I ever purchase anything offered to me as the result of an unsolicited e-mail message,” Ebert wrote. “Nor will I forward chain letters, petitions, mass mailings, or virus warnings to large numbers of others. This is my contribution to the survival of the online community.”

Not only was Ebert eager to correspond with and encourage skilled movie bloggers, but he also put his money where his mouth was, investing early in the Google search engine and making several million dollars doing so.

Ebert received honorary degrees from the American Film Institute, the University of Colorado and the School of the Art Institute. He is a member of the Chicago Journalism Hall of Fame and was honored with a sidewalk medallion under the Chicago Theatre marquee.

He first had surgery to remove a malignant tumor on his thyroid in 2002, and three subsequent surgeries on his salivary gland, all the while refusing to cut back on his TV show or his lifelong pride and joy, his job at the Sun-Times.

“My newspaper job,” he said in 2005, “is my identity.”

But as always with Roger Ebert, that was being too modest. He was a renaissance man whose genius was based on film but by no means limited to it, a great soul who had extraordinary impact on his profession and the world around him.

“Kindness covers all of my political beliefs,” he wrote, at the end of his memoir, “Life Itself.” “No need to spell them out. I believe that if, at the end, according to our abilities, we have done something to make others a little happier, and something to make ourselves a little happier, that is about the best we can do. To make others less happy is a crime. To make ourselves unhappy is where all crime starts. We must try to contribute joy to the world. That is true no matter what our problems, our health, our circumstances. We must try. I didn’t always know this and am happy I lived long enough to find it out.”

Survivors, in addition to his wife, include stepchildren Sonia and Jay, and grandchildren Raven, Emil, Mark and Joseph.