Comments on Lewis's ideas about reconciling stage and specificity in neo-Piagetian theory in this issue. Focuses on whether general stages, domain specificity, and individual diversity are compatible from a nonlinear, dynamic perspective. Suggests that, by using catastrophe theory, intra- and interindividual diversity and domain specificity can be…

To resolve tension between general stages and conceptual specificity in neo-Piagetian theory, R. Case introduced the idea of central conceptual structures. To resolve difficulties of separating developmental level and conceptual diversity, this article reconceptualizes central conceptual structures as self-organizing systems that stabilize in…

Comments on Lewis's ideas about reconciling stage and specificity in neo-Piagetian theory in this issue. Summarizes R. Case's central conceptual structure and its relation to other neo-Piagetian theories. Notes similarities between Lewis and Piaget, suggesting that differences adhere to a limited number of general laws instead of being…