Discusses the four "planes of development" posited by Maria Montessori: (1) from birth to age 6; (2) from age 6 to 12; (3) from age 12 to 18; and (4) full maturity. Although Montessori schools have been successful in dealing with children during the first two planes, efforts need to be focused on adolescents at the third stage. (MDM)

Discusses the four planes of development and the periods of creation and crystallization within each plane. Identifies the type of independence that should be achieved by the end of the first two planes of development. Maintains that it is through individual work on the environment that one achieves independence. (KB)