Written in 1904 (CW 9) Theosophy is a key work for gaining a solid footing in spiritual reality as described by Rudolf Steiner. It is organized into four parts. First, Steiner builds a comprehensive understanding of human nature: physical bodily nature; soul qualities; spirit being, or "I"-being; and the higher spiritual aspects. This leads us to Steiner's description of the human being as sevenfold: