taken from: http://us.imdb.com/CommentsShow?0052311
This is not a noir, mystery or thriller -- it just seems so. It is a meditation on space. No one before (except Welles himself in `Othello') had mastered the dimensionality of place as extensively. The actors are merely anchors, references for the camera as it moves around, under and behind planes. Everything is volume, space. Every shot is an adventure in directed perception of depth.
Reading about Heston's view of this film is a hoot. He has no idea what is happening and thinks it has something to do the devolution of Welles' character. Watch Heston in this film, vigorously chasing a greater awareness, and always being largely clueless. Welles used this against him without his knowledge. Same with Ms Leigh who was a manikin in character and `real' life.
In some future, schools will teach kids to be visually articulate, just as they presumably now teach literary competence. And as with now, some will actually get it. Millions of seventh graders will be exposed to this, because it is the purest spatial film -- the one that reveals its 3-d intentions more than Kane, Shanghai, Othello. Millions of kids will note that the story is about `planting' and discovering things and either hallucinating about or recording them. Millions of small essays will be written using Welles' memo as source (some noting similarities with Vincent's letters), but most kids will come out of the experience like Heston did.