. . . the basic idea [of activity theory] is not "evolution," that is, the idea of adaptation to the environment, but "revolution," that is, change of the environment.  The dialectical analysis of human history, as it was done, for example, by Hegel and particularly by Marx, showed not only that humans adapt to the environment but also that they change it in accordance with their demands . . .  Activity is not an active adaptation to the environment but the transformation of the environment and--in interrelation with it--of humans themselves.   Although  this  idea  is  not new, it has only begun to prove its explanatory potental.  Among the first to apply this idea to psychology were Vygotsky and one of his closest students, Leontiev.  (pp. 103-105)

In Finland, for thirty years, theoretical frames for early childhood education and preschool have been outlined through Bronfenbrenner's ecological approach, Vygotsky's developmental theory, didactic theories and the psychological theories of learning, among which the latest is the constructivist theory of learning.

The importance of the theory of ecological development lies in the fact that personal development is seen in relation to different kinds and different levels of systems. This has introduced to the methodological principles of educational research a systems approach, according to which an object is studied as a system of its structural and functional relations.

Early childhood education and preschool have received strong theoretical stimuli from developmental psychology. This is true of Finland even today and evident also in this article. Developmental psychology theories are represented here by the often referred to theories of Bronfenbrenner and Vygotsky. They both focus their attention on human development and both have introduced a systems dimension to their ideas.