'Christianity as Mystical Fact, and the Mysteries of Antiquity' is a collection of lectures given by Rudolf Steiner. He is best-remembered today for founding an esoteric spiritual movement, anthroposophy, with roots in German idealist philosophy and theosophy. The main idea that Steiner tries to convey in his series of lectures is that spiritual and scientific knowledge are not opposing positions—in actuality, according to Steiner, they complement one another.