I was listening to a speech, in Portuguese (confession: without my wife helping me to translate, I would be lost), by Geraldo Neto Lemos, (YouTube link here) one of the people who worked closely with Chico. He discussed how the series of books were written and psychographed by Francisco (Chico) C. Xavier.
He revealed how at first the people working with Chico didn’t believe the book Nosso Lar. They asked how could there be a city in the sky? Good question, I think of that myself. But then when I think of the different dimensions which exists all around us and how living in a multidimensional world is able to explain many of the spirit phenomena that we know exist. Then I begin to comprehend (barely) the complexity of our universe.
He also told us that a committee of 12 high spirits helped write the Andre Luiz books. He would only reveal one of the names of the spirits. That Socrates was one of the authors.
Geraldo further explained that the series of books just gives us a hint of the truth of the spirit world. The curtain was lifted enough to allow us a peek and what lies beyond.