[Ernest Freeberg, history professor at the University of Tennessee, is the author of "Democracy's Prisoner: Eugene V. Debs, the Great War, and the Right to Dissent," to be published by Harvard University Press this spring. This piece was first published in the Los Angeles Times.]

Moviemakers have not been kind to novelist Upton Sinclair, and "There Will Be Blood" is no exception.

In the early 20th century, Sinclair was one of the first serious writers to be fascinated by the movies -- as a source of income and as a way to spread his socialist ideas to a wide audience. Imagine his surprise when he watched one of the first movie adaptations of one of his novels, "The Moneychangers," in 1920. The filmmaker had turned a muckraking expose of Wall Street into a melodrama about opium dens in San Francisco. Sinclair may have been the first American novelist to protest that "it is the amiable custom of the film producers ... to take an author's name and the title of his book, and then write an entirely different story of their own, which they think will please the public better."

Some critics now praising "There Will Be Blood" have applauded producer Paul Thomas Anderson's decision to ignore the radical politics at the core of Sinclair's 1927 novel, "Oil!," the book that inspired the film. Sinclair wrote the story to expose the corrupt practices of Southern California's oil tycoons and the false prophets of its religion business, giving them the same treatment he had already provided in earlier books about coal companies, war profiteers, newspaper editors and Chicago meatpackers.

Although Sinclair's novel portrays the misdeeds of oil men convicted of bribery, the film portrays the murderous rage that lurks in the black heart of a wildcat oil driller named Daniel Plainview. Sinclair wanted his readers to see that capitalism was producing great riches, but only at the expense of good government. The film chooses cinematic spectacle and a star turn over political commentary, depicting a single man's struggle with dark but obscure demons.

Some critics' disdain for what one called Sinclair's "wishful editorializing" about socialism would not have surprised him, coming as it does from what he would have called the "plutocratic press." In his day, even some political allies thought his urge to propagandize marred his literary style. As a freelance radical, Sinclair dashed off novels at a feverish pace, eager to engage the headlines of his day, stir public unrest and make enough money to support himself while he tore into a new investigation. A poet comrade told him that he was dazzled by Sinclair's "velocity of execution" but was also "a little saddened, from the point of view of an artist, that you have not taken the years on this or that piece which would establish it as a permanently formed work of genius." Sinclair replied that nothing would please him more than the chance to write great literature. He often joked that, once he'd helped slay capitalism, he would devote his remaining days to fulfilling his dream of writing an epic tragedy in verse.

And so "Oil!" is a jampacked but pedantic novel, one that few would bother with today. Those who do read it, however, will find that the radical writer provided a surprisingly fair-minded portrait of the oil tycoon who is the story's main character. Sinclair shows us a man who takes justifiable pride in his ability to find and pump oil. In the process, he breaks strikes and bribes officials -- not because he is excessively greedy but because he knows how the game works in capitalist America. He plays by the rules as he finds them, and he is well-rewarded for giving the world what it wants.

The novel centers on this man's relationship with his son, a young idealist who loves his father but repudiates the family business when he joins the socialist cause. Though the father is bemused by his son's political heresies, and the son rejects his father's moral compromises, the two remain devoted to each other. Their blood is thicker than oil. In contrast, the oil man in "There Will Be Blood" hungers to succeed only out of spite for his fellow man. In the film's most quoted and most ludicrous lines, Plainview explains, "I have a competition in me. I want no one else to succeed. I hate most people. ... I want to earn enough money so I can get away from everyone." Even the orneriest robber baron never talked this way.

All the evils that Sinclair finds in the capitalist system, Anderson locates in the twisted psyche of a dangerous hermit. The movie ends with a violent rupture between father and son, set off not by the son's politics but by his deafness, caused by a drilling accident, and by his decision to go into the oil business for himself. The moral of this tale is murky, but we leave the theater knowing for sure that this is one very bad man. The novelist Sinclair shows us characters struggling to make hard moral choices in an economic and political system that rewards corruption and cynicism. The filmmaker chooses instead to tell the fantastic tale of a landlocked Capt. Ahab.

In short, the Hollywood filmmaker could learn a thing or two from the radical propagandist about balance, complexity and historical context.

For all of the film's critical acclaim and Academy Award nominations, this latest attempt to bring Upton Sinclair to the silver screen turned out much like the earlier try -- it uses Sinclair's name, but only to promote a sensational melodrama from a filmmaker who decided, no doubt correctly, that he knew better than Sinclair what would please movie critics and the ticket-buying public.