What is the theme in Lilith's Brood by Octavia E. Butler?

Freedom is a clear theme throughout the story of Lilith's Brood. This theme is first seen when the book opens and the only perspective given to the reader is that of Lilith, who is being held captive. She has moments when she appears to almost, or perhaps does, loose her sanity because of the cage she has been put in. She has very little freedom while in the cage. The rest of Lilith's story focuses on the freedoms that the people do not have now that they are being controlled by the Oankali.