Theosophy by Rudolf Steiner is a key work for anyone seeking a solid grounding in Anthroposophy, the spiritual understanding of the world as described by Rudolf Steiner. The book is organized in four parts. First, Steiner builds up a comprehensive understanding of human nature, beginning with the physical and etheric bodily nature and moving up through the soul nature to our spiritual being: the I, and then to the higher spiritual aspects of our being which will only become conscious and active principles in the future.
Continued study then leads the reader to an understanding of the human being as a sevenfold interpenetrated being of body, soul, and spirit. In the next section Steiner gives an extraordinary overview of the laws of reincarnation and the workings of karma as we pass from one life to the next. This prepares us for the third section where Steiner shows the different ways in which we live, during this life on earth and after death, in the three worlds of body, soul, and spirit, as well as the ways in which these worlds in turn live into us.
Theosophy is one of the most essential of anthroposophical introductory works as it provides all of the foundation concepts necessary for a proper understanding of his other books and lecture cycles.