The psychic landscape in Philip Dick's novels was delusionally paranoid. He asked you to consider the possibilities of alternate or altering subjective realities twirling around a maypole of a more generalised or objective reality. He challenged our basic assumptions about reality and about what we knew or thought we knew about our relation to it. No, wait uh sorry about that one, Jack, it appears that the earth is actually just a speck of dust floating around a tiny star on the edge of a great big universe. There are merely different layers or degrees of reality.
Reality is modular.
The plot to Time Out of Joint is only incidental to the real story. And the real story is not exactly what you find on the printed page. You are what you think, reality is never what you think and there is no spoon. Ask me if I think Philip Dick was a great writer. And I'd hafta tell ya's that it depends on your definition of what made for a great writer.