Every esoteric who's trying to develop himself inwardly must know about his connection with spiritual powers who live in the surrounding world and who stream in and out of him continually. When we look at a human being we first have his physical body. It's due to the working of spiritual beings that the physical body is put together the way it is. Archai work in the earth, water, air and fire elements. They stream in and out of his physical body. Likewise archangels are at work in his etheric body, and angels in the astral body. The sentient soul that developed out of the latter is worked on by the Exusiai. Dynamis work on the intellectual soul and Kyriotetes on the consciousness soul. Even high beings work on man's higher members: Seraphim on spirit self, Cherubim on life spirit and the Thrones on spirit man.
When an esoteric pupil wanted to know the essence of Christian teachings he had to look at this picture of man shaped like a tree that's rooted in the spirit. That's why they meant by Buddha sitting under the bodhi tree, or Nathaneal sitting under the fig tree. The world ash Yggdrasil is also a depiction of this tree.
The forces that work on the physical body are Archai. There's four kinds of these beings. They're not incorporated in physical bodies, they only have a corporality down to the ether. These are the four kings who work on man in the ether. Man owes his physical body to these beings who live in the ether. If one thinks of ever finer substances from solids to fluids, gases, warmth and ethers, one is getting the wrong idea about ethers for they are quite different from physical substances.
One should look upon the four forces in ether that work on man's physical body as the four temperaments. The substances of the four beings are the four temperaments. Beings who are incorporated in the choleric temperament work in man's warmth element, those in sanguine in his air, phlegmatic in water, and ones who are incorporated in the melancholic temperament work in his solid or earthy things. The melancholic temperament enables a man to form firm concepts that remain the same, so that if he thinks horse today it will remain the same concept for him tomorrow. Whereas the phlegmatic temperament keeps concepts fluid so that he can always take in new things. When a man thinks, his thoughts are firmer parts of the uniform mass of his aura. In some people thought forms tend to stay firm; in others they're constantly changing. If a man's forms of thoughts are flexible, new thoughts can press into them and the two understand each other very well. An esoteric must cultivate this flexibility of thought forms. This is of great importance for him. That a man can do this is based on phlegma. It's a mistake to say that a man has this or that temperament because he has this or that physical body. His physical body was formed out of the temperaments by the spirits who work in him.