The notion of the school as a learning community represents a fundamental shift in the ideology that shapes the understanding of schools and professional practice. The traditional view of schools is grounded in a mechanistic worldview and associated with a positivist epistemology, rationalist methodology, and a managed system. From this perspective, control and power reside at the top of the school organization, and roles, responsibilities, and spheres of decision making are clearly delineated. Wholes are composed of parts that can be removed and replaced, with ‘no intrinsic relationship of parts: parts are held together by an authoritarian hierarchy and discrete horizontal status divisions’ (O’Sullivan, 1999, p. 53). A fundamental assumption of this worldview is that there is one best way to do certain things, that this best way can be discovered through experimentation, that it comprises universally valid knowledge, and that it is best disseminated through direct instruction. These are the assumptions underlying Newtonian science, and this view of the world and of science has had a profound impact on human beliefs about how knowledge develops and how systems operate.