El Espinoza del Diablo

I'm really tempted to write in Spanish for this post, but I won't because I know that the few people who read it don't speak Spanish :( Anyway, before watching this film I thought that it was supposed to be a horror flick. It has some scary movie qualities and there was a least one part where I almost jumped out of my seat, but overall it was more of a sad drama. In an interview that I saw with the director, G. del Toro, he said that he wanted to portray just how dangerous it was to be a child. He succeeded with this film! The lives of the boys in this film were perilous and it was shown just how fragile we humans are.
One of the discussions that the group had after watching the film is "why did the director choose this title?" In the film one of the characters, Dr. Caseres, shows the one of the boys, Carlos, a jar with a preserved fetus inside it. The fetus has a protruding backbone that is oddly deformed. Dr. Caseres explains that the people in the village call this deformity "the Devil's Backbone" and say that children born like this were never supposed to be born. The fetus is preserved in a special mixture of rum and other spices, "limbo water". Dr. Caseres sells limbo water to the townspeople because they believe that it cures infermities and impotence. Anyway, one of the theories about the title was that the film was about a child who shouldn't have been born, Jacinto. I like this theory, but I'll propose another. Santi is suspended in the kitchen cistern. Whenever he is seen in the film, it's as if he is floating. He tries to warn Carlos that the boys are in danger and in the end he helps them to defeat their enemies. The very water that he is suspended in is used to save them.
The properties of the ghosts in this film are interesting too. They seem to be subject to some of the laws of physics, but not to others. They don't walk through walls, they cast shadows, and they leave behind physical evidence of themselves (footprints, a dropped handkerchief, blood, etc.). On the other hand they can be invisible, they exist, and they seem to be able to move to where ever they want to be. Is this because they still expect certain laws to apply to them and the other things happen when they aren't thinking about it?