Rudolf Steiner's superb thesis provides deep insight into spiritual science, and the history of mankind as viewed through the philosophy of the anthroposophy movement he founded. An Outline of Esoteric Science attempts to reconcile mankind's spiritual being with the scientific exactitude which had emerged among scholars in the 19th century. Steiner lays out the spiritual realms which are invisible to us, attempting to use a defined precision similar to that which had emerged in science. In the final section, this book refers to the spiritual development and contemplation necessary for individuals to see the spiritual realms and planes which comprise existence and the universe. The means by which individuals may train themselves introspectively to see are detailed by Steiner, whose theosophical philosophy was, by the time of this book's publication in 1909, well-developed.