Curious about the astral realm.
So what I've come to understand is that within Steiners ontology the human being is composed of four layers, the physical body, the aetheric body, the astral body, and the I. Each of these corresponds to a particular kind of substance in the world, which I think I've heard also corresponds to the four classical elements. Now my question is this, if each of these are particular kinds of substance, why is it possible to cleanly differentiate the universe into distinct realms, after all, the classical elements that we see on earth are all overlapping and jumbled up with one another. Is the cosmos like a jar or sediment where these different kinds of substance are layered due to differences of density? Also people talk a lot about the astral and physical realms, is there also an aetheric realm?