The Nordic runes are taken off an ancient model for the structure of an Indo-European's mind. It is called Yggdrasil. That model was known to the ancient Greek philosophers, it underlies Gnosticism and Alchemy and it is consistent with Yoga and Hinduism. The common factor is that all of these peoples were Indo-Europeans. Explaining this model and the esoteric meaning of the runes is the principle purpose of this book. It also puts the runes' development into their historical context. The contemporary importance of this model is that it underlies Carl Jung's work in psychology, and also tells how to reach the highest level of person development.