Man, Woman, and Child in the Light of Spiritual Science
The physical body develops until the child's first teeth change. Of course, the human being continues to grow, but this growth is only an enlargement of the form, an expansion of the shape that it has acquired by the age of seven. This is an important regulator for education. Until this time, the physical form of the child should be developed first. If this is not done, something has been neglected for the whole life of the person concerned. In the second period, up to puberty, the etheric body develops. Of course, it was not inactive before this time. It is just that until the teeth change, the etheric body is enclosed in a kind of mother's shell. Only from this time on does it become free and able to unfold. At sexual maturity, the development of the etheric body reaches its conclusion, and from now on the development of the astral body becomes free. Even later, the actual formation of the ego begins.