This film is a story of the old gods. Solness is the Demiurgos, the Insane God who created the Earth and the Universe we live in.
Seen in this light, suddenly the film makes sense.
The dialogue is encoded. Note how the discussions in the first few scenes are nonspecific to the point of nonsense.
That is - unless you know the code.
They are talking about the creation of the Universe (by Solness), and who will take it over, and who will create the next one (the Villa by the Lake).
Does Ragnar have the Right Stuff to be a God? That is in question. Solness says "No".
Ragnar? Ragnarok, Chaos. The Undoing. The coming apocalypse that Kaia (Gaia) will participate in (the Wedding). This is about whether the Earth will go through Apocalypse, Chaos, and begin anew, or whether She will hang on with Solness in the old way, and try and work it out.
Solness is in love with Kaia, but in reality he wants to keep Ragnar (Lucifer?) close because he needs him. Light and Dark being nothing without each other. In this case Lucifer is not to be confused with Satan (Shaitan - the Opposer) who is mere darkness as in - when the old sun (Saturn) went away. He is The Light Bringer, the Shining One of Milton.
The film is also Masonic in a BIG way. But that is an easier decode, and I will leave it to "Jay" who works at that level.
