Four Planes of Development

Dr. Montessori was asked toward the end of her career what her greatest achievement was and her response was that it was the development of the four planes of development.

In the above diagram, the person's first 24 years of life is divided into four planes of 6 years each. Each six-year plane is also divided into two sub-planes of three years each.

For each sub-plane there is a corresponding Montessori environment for that three-year age grouping. The exception is the first three years of life, which is further subdivided into Nido (6 weeks to 18 months) and Toddler (14 to 36 months).

Bergamo Acadmey currently has Toddler, Primary, and combined Lower/Upper Elementary environments. In the future, Bergamo Academy may open an Erdkinder in a rural location outside Denver, which is a farm school suited for the beginning of the third plane (ages 12-15), a time Dr. Montessori referred to as the "second infancy", a time of great physical and emotional growth that parallels the first three years of life. This parallelism is highlighted by the dashed blue lines.

Later, Dr. Montessori refined her diagram to make it more illustrative. The above is called the "bulb diagram" and is suggestive of how the first six years of life are the most formative. This is contrast to the ramp below it that depicts conventional education where the first six years of life are ignored. Also, in the upper part of the bulb diagram that represents the Montessori philosophy, the person (student) develops oneself to his/her final purpose. In contrast, in conventional education the person is pushed along a path pre-determined by a pedagogy not rooted in scientific observation the way Dr. Montessori developed her method.