Andrew Sarris, who died on Wednesday at age 83, was the greatest film critic this country has ever produced. He is best known for introducing auteur theory to America, the notion that a director can be the author of the film in the same way that a composer can be the author of a concerto or a novelist the author of a novel. But he was far more than a theory and more flexible in his application of that theory than others who followed him.

His reviews and articles in the Village Voice, where he worked for 29 years, were where two generations of readers went to learn about the movies. It was just understood: If you really wanted to know about something - if you wanted to know why something was important and why it was good - you read what Andrew Sarris had to say about it. Say there was a festival of foreign cinema, or a festival of classic film. Say you were curious. You read Sarris, and he was your gateway. Then you knew what to look for. Then you understood and could build on that understanding.

Sarris was consummately erudite but completely down to earth. He never forgot that people went to the movies to fall in love. He never forgot that movies were a place of feelings, and this was reflected in his film criticism, which was full of his personality, though never about his personality. (He never got caught up in his own cult.) He could be acerbic or funny or naked in his emotions. His was a gut-level response, refined by reflection and raised to the level of art.

He had a magnificent confidence and a keen ability to see the truth. Many auteurist critics fall into the trap of supporting a director's worst work, so long as the work seems characteristic of the director. But Sarris knew that just as siblings can look alike and yet one be ugly and the other beautiful, so can two movies, with a family resemblance, be of varying quality. He famously turned on Michelangelo Antonioni's work when it got obscure and lifeless, and he had the intellectual honesty to recognize when Stanley Kubrick's films dropped to sub-zero temperatures.

Because of auteur theory, Sarris is most usually thought of as a director-centric critic, and this is not unfair. His promotion of the French New Wave in America, as well as his early recognition of the importance of Hitchcock's "Psycho," Samuel Fuller and Howard Hawks were more than influential; they were determinative. His writing about them changed the landscape of critical thought in the United States.

But Sarris was also a superb critic of actors and actresses. His discussions of Greta Garbo, James Cagney, Humphrey Bogart, Vivien Leigh and others are the best you'll find, anywhere. Indeed, if you're a film critic and want to feel sick - and wish you'd thought of this, and wish you'd said that - get a copy of Sarris' "You Ain't Heard Nothin' Yet: The American Talking Film, History and Memory, 1927-1949," a dazzling analysis of the genres, stars and directors of Hollywood's Golden Age.

It's also worth noting that in addition to writing books, Sarris was a journalist, covering the film beat as a critic, first at the Voice and later for the New York Observer, for many decades. The quality of the work never flagged. Read virtually any Sarris review, including his most recent, and you'll find something in there, some observation, some turn of phrase, some unexpected truth. And this was not the work he was doing for posterity. This is what he was doing on a Wednesday for Friday's paper.

I never met Sarris, but I feel as though I knew him, both through his work and through the vivid portrayal of him in "Love and Other Infectious Diseases," a memoir by his wife, Molly Haskell (an extraordinary critic in her own right). For years, I've said that he was the only fellow film critic that I'd call "Mr." - and that's only because "Your Lordship" might sound too florid. He wasn't just a giant. Mr. Sarris was the giant - and utterly irreplaceable.

Mick LaSalle is The San Francisco Chronicle's move critic. E-mail: