In this selection of insightful lectures, Rudolf Steiner addresses the mystery of evil, offering a complex and original picture. Evil, he asserts, is a phenomenon that arises when something appears outside its true context. A thing which is initially "good, " therefore, can become "evil" when it is out of place. He speaks of this as the effect of particular spiritual beings -- principally Lucifer and Ahriman -- who work as polar forces, putting hindrances in our path. Yet confronting and coming to terms with such difficulties can ultimately further our development, as these fascinating lectures show us.