Recognising that 'the longer one does attend to a topic the more mastery of it one has,' the great American psychologist William James remarked, 'An education which should improve this faculty would be the education par excellence.' (1892/1985, p. 95) Montessori, who knew of James, set out to do just that. She believed that if environments could be prepared with 'objects which correspond to...formative tendencies' (1949/1967, p. 169) the child's energy and interest would become focused on that aspect of the environment which corresponded to the developmental need.