Reflecting the focus of a Jean Piaget Symposium entitled Biology and Knowledge: Structural Constraints on Development, this volume presents many of the emergent themes discussed.

Among these themes are:

• Structural constraints on cognitive development and learning come in many shapes and forms and involve appeal to more than one level of analysis.
• To postulate innate knowledge is not to deny that humans can acquire new concepts.
• It is unlikely that there is only one learning mechanism, even if one prefers to work with general as opposed to domain-specific mechanisms.
• The problems of induction with respect to concept acquisition are even harder than originally thought.