Addresses the extent to which differences in Piagetian and Vygotskyan psychologies make their theories incompatible. Differences result from a Vygotskyan belief in a material primary cause for development; Piagetians do not hold this view. Explores this difference in perspective, concluding that, despite it, the two approaches are compatible. (JW)

Contrasts work of Leontiev and Vygotsky. Suggests that Leontiev concentrated on social activity as a whole, whereas Vygotsky made semiotic mediation through culturally developed symbols a central aspect of his analysis. Maintains that they shared a philosophical base and that Leontiev used Vygotsky's ideas as a starting point to explore human…

Explores developmental issues regarding domain theory, a theory explaining moral development. Concludes that this theory does not explain how domains of moral reasoning and behavior evolve, neglects social and historical aspects of domain development, and does not recognize the effects of individual differences on domains. (JW)