"There Will Be Blood" is the kind of film that is easily called great. I am not sure of its greatness. It was filmed in the same area of Texas used by "No Country for Old Men," and that is a great film, and a perfect one. But "There Will Be Blood" is not perfect, and in its imperfections (its unbending characters, its lack of women or any reflection of ordinary society, its ending, its relentlessness) we may see its reach exceeding its grasp. Which is not a dishonorable thing.
    — Roger Ebert, rated 3.5/4 stars.

The uneasy interaction between God and secular commerce is the film's most important recurring notion. It's where "There Will Be Blood" could have had something definite and compelling to say, but instead it's precisely there that we find the film's Achilles' heel. Anderson doesn't take the religious mind seriously enough to understand it, leaving Dano to play a generalized character who is somewhere between a freak and a phony. The scenes between Day-Lewis and Dano ultimately degenerate into a ridiculous burlesque.

Still, individual scenes and sequences - for example, the entire section in which Plainview gets to know his "long lost" brother - are too strange, haunting and emotionally right for the film to be dismissed. There should be no attempt or temptation to dismiss it. At the same time, there should be no need to pretend "There Will Be Blood" is a masterpiece just because Anderson sincerely tried to make it one.
    — Mick "Often Wrong" LaSalle, SFGate. Rated Man-masturbating-under-a-hat out of Man-cavorting-like-a-seal stars.

This tension between realism and spectacle runs like a fissure through the film and invests it with tremendous unease. You are constantly being pulled away from and toward the charismatic Plainview, whose pursuit of oil reads like a chapter from this nation’s grand narrative of discovery and conquest. . . But the film is above all a consummate work of art, one that transcends the historically fraught context of its making, and its pleasures are unapologetically aesthetic. It reveals, excites, disturbs, provokes, but the window it opens is to human consciousness itself.
    — Manohla Dargis, New York Times.

When Anderson was shooting the movie in Marfa, the Coen brothers were making a Western of their own, No Country for Old Men. As Anderson and his crew tested the pyrotechnic system used in the oil derrick scene, a huge billow of smoke drifted across Marfa and into the Coens’ shot. The brothers were forced to suspend shooting for the day. The Coens would have their revenge more than a year later, on Oscar night, when No Country bested There Will Be Blood for Best Picture, Best Director, and Best Adapted Screenplay. But Blood may be the movie that transcends time.
    — “A Whole Ocean of Oil Under Our Feet”: ‘There Will Be Blood’ at 10.