You will have gathered from the lectures given here recently that when we ascend with clairvoyance into the higher worlds we there meet with beings who, it is true, do not belong to our physical world, but who are in themselves so independent that we can describe them as ‘persons’ for those worlds, just as we call men here on the physical plane ‘persons.’
You have seen that groups of animals of the same species together belong to a group-soul or group-ego and that on the astral plane we come upon the lion-soul, the tiger-soul, and so on, as independent personalities whom we can meet there as we meet the human being on the physical plane.
In the same way we find in still higher regions, on the devachanic plane, the egos of quite large plant groups, and in the highest parts of Devachan we find the egos of the minerals, personalities as distinct as men are here on the physical plane. We saw in this way that in these higher worlds we meet with certain beings who, so to speak, extend part of their organism, their separate members, down into the physical plane.
If a man were to extend his fingers through openings in a curtain or partition we should only see the ten fingers, the man himself would be behind the partition. So it is with the group-egos of the animals. Here with the physical eye we see what is extended down below as members by higher beings of the astral world, and the actual ego is behind the partition, behind that wall which separates the physical world from the astral world.
Source: Rudolf Steiner – GA 102 – The Influence of Spiritual Beings on Man: Lecture I – Berlin, 6th January 1908