Plainview has been likened to Satan, but I fear that he is all too human, representing a side of humanity, an aspect of American identity and aspirations that most of us would fear to touch or even come close to. The excesses of both capitalism and religion - the US's twin obsessions - are what are on show here, in a vision so black, so darkly humourous, that it recalls Beckett or Ionesco, or Kubrick.
What is almost another character in the movie is the remarkable score. Beginning like a hive of demented bees, and in turns atonal, dissonant, mesmerising or frantic, it jars, disrupts, sets on edge in the same way as Daniel Day Lewis' eyes contrast with his cultured, almost plummy voice. At peak moments, we suddenly hear Brahms violin concerto as yet another signal of the contrast between the romantic ideal of the American Way and the vicious, amoral behavior on the screen.
This is in many ways not a pleasant movie; it is sometimes difficult to watch. But it is risky, bold, confident filmmaking, by a director in complete control of his craft in partnership with an equally fearless actor.