10 lectures, Helsinki, April. 3-14, 1912 (CW 136)Rudolf Steiner's achievement in these lectures--it has been said by Valentin Tomberg--"cannot be compared with the accomplishment of any contemporary seer or thinker, or with any of the Middle Ages or antiquity. It towers over them."In the architecture of Rudolf Steiner's great cosmological temple, this extraordinary course of lectures on spiritual beings forms the central pillar with other important texts su...