"The second great wave of evolution, the evolution of form, and the third great wave, the evolution of self-consciousness, will be dealt with later on. These three currents of evolution are distinguishable on our earth in connection with humanity; the making of the materials, the building of the house, and the growing of the tenant of the house, or, as said above, the evolution of spirit-matter, the evolution of form, the evolution of self-consciousness. If the reader can grasp and retain this idea, he will find a helpful clue to guide him through the labyrinth of facts. p. 45"