“A key lesson is a new experience, skill, or concept that orients or informs and allows the human being the possibility to integrate the experience into his or her existing schema after some related physical or mental activity which alters existing schema in light of the new information. A key lesson can be given by any adult, a peer, or an experience.” (Baker, Kay). The key lessons, follow the Great Lessons (see Storytelling) which give the learner an overview of an area of the curriculum and present a unified vision of multi disciplines rather than compartmentalised knowledge.

“To speak to him is not enough for this; it is necessary to interest him. What he learns must be interesting, must be fascinating. We must give him grandeur. To begin with, let us present him with the world.” (Montessori, Maria, From Childhood to Adolescence, p. 19) “The Cosmic Plan can be presented to the child, as a thrilling tale of the earth we live in, its many changes through slow ages… how land and sea fought for supremacy, and how equilibrium of elements was achieved, that Life might appear on the stage to play its part in the great drama... illustrated as it must be by fascinating charts and diagrams, the creation of earth as we now know it unfolds before the child’s imagination, and always with emphasis on the function each agent has to perform in Nature’s household, whether consciously or unconsciously….” (Montessori, Maria, To Educate the Human Potential, p. viii)