The Philosophy of Spiritual Activity (Lindemann) (Books Section) By Rudolf Steiner | September 9, 2013 - 4:01 am |September 9, 2021 Anthroposophy, Books, Occult Science, Recommended, Rudolf Steiner Link: http://wn.rsarchive.org/Books/GA004/English/AP1986/GA004_index.html Bookmark the permalink.