These profound studies of the cosmic forces behind the four great festivals of the year provide a wealth of material for fruitful meditation. Rudolf Steiner presents great imaginative pictures which unite the heavens and the earth through a portrayal of the activities of the archangels Michael, Gabriel, Raphael and Uriel. In the course of the lectures he offers spiritual wisdom on subjects which include the alchemical processes of sulphur, mercury and salt in the cosmos, man and the plant, spiritual combustion processes, crystals, clouds, meteors, the movement of elemental beings in nature, and the conflicting efforts of the two great adversaries to divert the earth from its true goal.