It must above all things be emphasized that this world is woven out of the substance of which human thought consists. The word “substance,” too is here used in a far from strict or accurate sense. Thought, however, as it lives in man, is only a shadow picture, a phantom of its true nature. Just as the shadow of an object on the wall is related to the real object that throws this shadow, so is the thought that makes its appearance through a human brain related to the being in the spiritland that corresponds to this thought.
When his spiritual sense is awakened, man really perceives this thought being, just as the eye of the senses perceives a table or a chair. He goes about in a region of thought beings. The corporeal eye perceives the lion, and the thinking directed to the sensibly perceptible thinks merely the thought, “lion” as a shadow, a shadowy picture. The spiritual eye sees in spiritland the thought “lion” as really and actually as the corporeal eye sees the physical lion.
Here we may again refer to the analogy already used regarding the land of the soul. Just as the surroundings of a man born blind operated upon appear suddenly with the new qualities of color and light, so do the surroundings of the person who learns to use his spiritual eye appear as a new world, the world of living thoughts or spirit beings. In this world there are to be seen, first, the spiritual archetypes of all things and beings that are present in the physical and soul worlds. Imagine a painter’s picture existing in his mind before it is painted. This gives an analogy to what is meant by the expression archetype. It does not concern us here that the painter has perhaps not had such an archetype in his mind before he paints and that it only gradually develops and becomes complete during the execution of the picture.
In the real world of spirit there exist such archetypes for all things, and the physical things and beings are copies of these archetypes. It is quite understandable when anyone who only trusts his outer senses denies this archetypal world and holds that archetypes are merely abstractions gained by an intellectual comparison of sense objects. Such a person simply cannot see in this higher world. He knows the thought world only in its shadowy abstraction. He does not know that the person with spiritual vision is as familiar with spirit beings as he himself is with his dog or his cat, and that the archetypal world has a far more intense reality than the world of the physical senses.
Source: Rudolf Steiner – GA 9 – Theosophy -Chapter III: The Three Worlds: 3. The Spiritland