The Invisible Elements of Human Nature and Practical Life
Human beings can spoil what nature has given them. Just as a plant could only become deformed if the etheric or life body did not regulate what is going on, so human beings develop an inner deformity if they work incorrectly from within, from the ego, on the lower members. The astral body must be permeated in a healthy way by the experiences of the ego. Those who do not want to admit that an astral body is at work in the development of the child's brain will also not realize how important it is for the ego to act correctly on the astral body. But those who understand this will say to themselves: You can continue where nature has left off. If you allow the whole range of sensations to run their course in a healthy way, this will continue to affect your physical body, your brain, and in this way you will build up your physical body throughout your whole life.