With rare exceptions these teachers lead the main lesson at the beginning of each day. Other teachers handle special subjects, but the class teachers provide the continuity so often lacking in our disjointed world today. The class teacher and the children get to know each other very well, and it is this teacher who becomes the school's closest link with the parents of that class. This experience of class community is both challenging and deeply rewarding to teachers. Having to prepare new subject matter as their students get older from year to year is a guarantee against going stale.
Children begin to see that a human being can strive for a unity of knowledge and experience.
When children reach high school age, the pupil-teacher relationship changes specialist teachers replace the class teacher. Physics, for example, is introduced in the sixth grade and continued each year as a main lesson block until graduation. As the students mature, they engage themselves at new levels of experience with each subject. It is as though each year they come to a window on the ascending spiral that looks out into the world through the lens of a particular subject. Through the main-lesson spiral curriculum, teachers lay the ground for a gradual vertical integration that deepens and widens each subject experience and, at the same time, keeps it moving with the other aspects of knowledge.