A Montessori education is holistic, it considers all aspects of development: physical, aesthetic, social, emotional, spiritual and cognitive. Maria Montessori viewed life as a series of transformations, each stage characterized by the emergence and disappearance of special potentialities or sensitivities. This series of transformations is a natural, normal, spontaneous process through four planes of development: the first from birth to six years, the second from six to twelve, the third from twelve to eighteen, and the fourth from eighteen to twenty-four. A child progresses from sensory motor to abstraction to moral development. Montessori is a child-centered pedagogy designed to help children with their task of self-construction as they develop through these planes, from childhood to maturity.