Responds to Noam's (PS 524 984) and Cicchetti's (PS 524 985) articles in this issue. Suggests that researchers should turn to the coactions of the internal and the external constraints on development that codetermine performance. States the position that cognitive developmental theory, when sensitized to intra- and interindividual differences,…

Focuses on the conceptual implications of analyses of individual differences in francophone post-Piagetian research. Maintains that these analyses are preoccupied by the "American question" of measurement and method, instead of attempting a theoretical account of the issues raised by intraindividual and interindividual variability in…

Notes that change in the moral and cognitive realms is a long-term historical process that includes progression and regression. Reconstructs the cognitive correlates of historical progress, using as examples the emergence of invariant numbers in Mesopotamia, the growth of logic and perspectivism in the early Middle Ages, and the rise of public…