This masterwork of the esoteric places humankind at the very heart of the vast, invisible processes of cosmic evolution. Esoteric science is the science of what takes place esoterically, in the sense that it is perceived not outside in nature but where one's soul turns when it directs its inner being toward the spirit. Rudolf Steiner worked on rosicrucian cosmology for many years to make it increasingly precise and accurate. This work remains the most effective presentation to date of a spiritual alternative to contemporary materialist cosmologies and of human evolution. Readers learn how the creation and evolution of humanity is embedded at the heart of the vast, invisible web of interacting cosmic beings, through whom the alchemical processes of cosmic evolution unfold. A detailed, practical guide to the methods or exercises, including the Rose Cross Meditation," through which such initiation knowledge can be attained.