“Magnolia” is one of those rare films that works in two entirely different ways. In one sense, it tells absorbing stories, filled with detail, told with precision and not a little humor. On another sense, it is a parable. The message of the parable, as with all good parables, is expressed not in words but in emotions. After we have felt the pain of these people, and felt the love of the policeman and the nurse, we have been taught something intangible, but necessary to know. That Paul Thomas Anderson thinks and creates in this way is proven again in his latest film, “There Will Be Blood” (2007). It is another film with an enigmatic ending, one that “Magnolia” teaches me I will have to think more carefully about.