On a fundamental level, I define it as the stuff in the world that's beyond the purely material, that transcends physicality. Things like Mathematics, Love, Bea

On a fundamental level, I define it as the stuff in the world that's beyond the purely material, that transcends physicality. Things like Mathematics, Love, Beauty, etc. Things that I believe will continue to "exist" (in some sense) beyond the existence of the universe around us. As Steiner puts it, "science, religion and art" all try to bridge this dichotomy of the physical vs the spiritual. So, no, it's nothing to do with ghosts and stuff.