The Montessori classroom is an environment prepared by the adult for learners. It contains all the essentials for optimal development but nothing superfluous. Attributes of a prepared environment include order and reality, beauty, and simplicity. Everything is child-sized to enhance the children's independent functioning at the early levels. The outdoors, a trained adult, and a large enough group of children of mixed ages make up a vital part of the prepared environment. (Haines)

“This environment has a dominant part to play in the process of maturation. …As regards psychological maturation, this can only occur by environmental experience, and the latter changes its form at each level of development because of the horme (inner drive) changes in its type, appearing in the individual as an intense interest for repeating certain actions at length for no obvious reasons, until—because of this repetition—a fresh function suddenly appears with explosive force.” (Montessori, Maria, The Absorbent Mind, p. 85) “This environment must provide a great deal of mental food and warm loving treatment…we must create an attractive environment… put everything that is good for the mind, along with an understanding and affectionate person.” (Montessori, Maria, 1946 London Lectures, p. 114)