This book presents the philosphical, psychological, and educational ideas of Maria Montessori. Chapters deal with: (1) the contribution of Montessori's ideas to philosophy, education, science, and child development; (2) the relationship of the Montessori materials to a child's intellectual, emotional and social development; (3) Montessori's view of people in relation to modern psychology; (4) the psychological value of work in school; (5) the Montessori view of the process of education and learning; (6) education in a changing world; (7) Montessori philosophy as related to the rapidly changing values of society; and (8) the concept of cosmic education. An appendix contains observations of a Montessori classroom. (SB)