A good curriculum must respect the hierarchical nature of knowledge. A fundamental error committed by today's schools is the inversion of this hierarchy. Science classes begin with Newton's laws of motion; history classes begin with controversial current events; math classes begin with set theory. These topics precede, or preclude, the more basic concepts that make them graspable. In this lecture, Mrs. VanDamme discusses how most elementary programs, including the Montessori elementary curriculum, violate the conceptual hierarchy. She offers an overview of the proper, hierarchical approach to each of the major subjects. And she discusses how this approach has produced thorough, first-hand knowledge, and consequently passionate enthusiasm, in her own students.