Throughout the ages, traditional folklore has spoken of guardian angels as spirits who guide and protect human beings. In modern times, however, their existence has largely been written off as myth and superstition. Based on his personal experience and cognition, Rudolf Steiner speaks of guardian angels and other spiritual beings as a reality. Their existence, he says, is a spiritual and scientific fact which can be fruitfully researched and studied through clairvoyant means. Furthermore, working consciously with these entities can assist each of us in fulfilling our evolutionary goals. In these six specially selected lectures, Rudolf Steiner elucidates the role of the guardian angel, and also discusses our relationship to the heavenly hierarchies of spiritual beings as a whole, and how they shape our human form as a result of their cosmic activity.