Maria Montessori based her pedagogical method on a theory she formulated through scientific observation of children and humans. The most basic units of this theory are the assimilative – receptive – mind, human tendencies, stages of development, sensitive periods and the mathematical mind of man.
If we were to liken man to a car and his evolution to the route he has to travel, the assimilative mind would be its engine, human tendencies its fuel, sensitive periods its headlights, stages of development the completion of a part of its route, and the mathematical mind its counter.