From Rudolf Steiner’s Secret Brotherhoods and the Mystery of the Double (CW 178), lecture 2, “The Mystery of the Double. Geographic Medicine, St. Gallen,” 16 November 1917 (audio excerpt below, read by Dale Brunsvold).
“We arrive in this world with the garment of our organism, without being able to reach down into it with our soul to any great extent. Instead, shortly before we are born … there is also an opportunity for another spiritual being apart from our soul to take possession of our body, namely, of the subconscious part of our body. This is a fact. Shortly before we are born, another being indwells us. In the terminology we use today we would call this an Ahrimanic being. It is just as much in us as is our own soul.
These beings lead their lives by making use of human beings to enable them to inhabit the sphere in which they wish to dwell. They have an exceptionally high degree of intelligence, and a very significantly developed will, but no qualities of soul, nothing like what we would call the human qualities of soul and heart and mind. So we proceed through our life while having our soul and also a double who is far cleverer, far cleverer than we are; very intelligent but with a Mephistophelean intelligence, an Ahrimanic intelligence. And in addition also an Ahrimanic will, a very strong will; a will that is much more akin to the forces of nature than it is to our human will, which is ruled by our heart and mind.
In the 19th century science discovered that our nervous system is interspersed with forces of electricity. Science was quite right. But the scientists are wrong if they believe that the nervous force which belongs to us, and which provides the foundation for our inner world of pictures and thinking, has anything to do with the electric currents that course along our nerves. These electric currents are the forces that are introduced into our being by the being I have just been describing. They do not belong to our being at all.…
These beings have decided, out of their own will, that they do not want to live in the world to which they were assigned by the wise gods of the upper hierarchies. They want to conquer the earth, so they need bodies. Having no bodies of their own, they use as much of human bodies as they can, since the human soul cannot quite fill out the human body. While a human body is developing, these beings can slip into it at a specific point before birth, and, thereafter, they accompany us beneath the threshold of our consciousness.
But there is one aspect of human life which they cannot stand, and that is death. So they always have to depart from the human body they have invaded before it is afflicted by death. This is again and again a bitter disappointment for them, for what they so much want to succeed in is to remain in the human body beyond death. In their own Kingdom this would be a high achievement for these beings, but so far they have failed in this. If the mystery of Golgotha had not taken place, if Christ had not passed through the mystery of Golgotha, these beings would long since have gained the ability on earth to remain in the human body after a karmically predetermined death. They would then have gained control over human evolution on earth, and would have become the masters of this human evolution on the earth.
.… These matters have long been known to certain secret Brotherhoods, who are very well informed about these things yet have withheld this information from humanity at large.… This knowledge must take hold of people in the right way, and cannot be allowed to be spread around by secret Brotherhoods who want to use it as a way of increasing their power. Nor above all may it be permitted to be kept secret as a means of increasing the power of certain Brotherhoods who work egoistically.…
This double of whom I have been speaking is neither more nor less than the originator of all physical diseases that arise spontaneously from within. And to know this being fully is what is meant by organic medicine. Diseases that come spontaneously from within, not those caused by external injuries, do not come from the soul but from this being who is the originator of all organic diseases that arise spontaneously from within.
… Psychoanalysis, together with other ways of thinking … involves having to deal with spiritual entities while not knowing enough about them. So one is at a loss as to how to deal with phenomena that are entering more and more into human life. It will thus be necessary for certain things to happen, even things that may be harmful in one respect must happen, because people need to be exposed to this harm in order to overcome it, and gain strength by doing so.”