The origins of knowledge
As we have seen, there is a significant difference between the traditional and the ecological systems view of the mechanisms by which knowledge arises. In this first section I review the different positions, and analyze a modern version of the tradi tional view, Jean Mandler's (1988, 1992, 1997), to show how easy it is for a mixed, in fact, contradictory paradigm to be used, as she herself describes processes which are consistent with those of dynamic theorists, yet retains traditional dichotomies. I try to show just why she is bound to take the position she does, given certain traditional assumptions she makes and to once again emphasize where the differences are significant and incommensurable (cannot be evaluated within the same paradigm). In the second section I consider the origins of knowledge from a dynamic ecological perspective to show that the same developmental principles underpin the means by which knowledge of the physical and social worlds emerges, but that knowledge of the social world does require the utilisation of different sorts of invariances than are suffi cient to understand the physical world. Finally I look back over the route we have taken. First, a review of the alterna tives.