Feelings and passions are (in the astral world) expressed by plant and animal forms. When man begins to behold his passions in the astral world he sees them as animal forms. These forms proceed from himself, but he sees them as if they were assailing him. This is because his own being is objectivised — otherwise he could not behold himself. Thus it is only in the astral world that man learns true self knowledge in contemplating the images of his passions in the animal forms which hurl, themselves upon him. A feeling of hatred entertained against another being appears as an attacking demon.
This astral self-knowledge occurs in an abnormal way in those who are troubled with psychical illnesses which consist in constant visions of being pursued by animals and menacing entities. The sufferers are seeing the mirror images of their emotions and desires.
Source: Rudolf Steiner – GA 94 – An Esoteric Cosmology – Lecture IX: The Astral World – Paris, 2nd June 1906
Translated by Rene Querido