Piaget has formulated a theory of knowledge construction. This theory and model postulates a direct or inversed isomorphism between ontogenetic and historic knowledge construction, and works with a unified theory and model of knowledge construction of a general epistemic subject, using equilibration as the main mechanism of construction, based on biological theory (embryology, elements of neo-darwinism). The identification of ontogenetic and historic knowledge construction cannot be defended any longer, because there are quite different mechanisms and factors of knowledge construction at work. For example, ontogenetic knowledge construction takes place within the particular contexts of the family, peers, school and a social context, whereas historic knowledge construction takes place in a variable historic context with varying influences of political, economic and intellectual fields, with variable forms of collaboration, competition, exchange and production. It is realized by groups of adults who attempt in an intentional way to optimize parts of their representations of their environment according to historically variable criteria. For example, there are varying forms of financial support of knowledge construction, and distinct forms of knowledge appropriation and distribution in historical forms of knowledge production. Therefore, it seems necessary to differentiate the theory of Piaget, and to elaborate distinct versions of ontogenetic and historic knowledge construction, with partly quite different mechanisms at work, using also other elements of biological theory. This project will work out an outline of these two theories and models of knowledge construction, and specify the links between them.