ABSTRACT
Piaget’s theorizing can be seen to exist in three distinct tiers (in a form which parallels theory building in biology; see e.g. Maderson 1982). In the first tier Piaget collected data concerning the occurrence of certain observed behaviours amongst children of various ages. In the second tier he imposed upon those observed behaviours a classificatory system in which he characterized some behaviours as formal operational, some as concrete operational, and still others as pre-operational. In the third tier he attempted to theorize his behavioural accounts, classifications and the progression of the subject towards intellectual maturity by relying on a meta-system based on principles drawn from logic and mathematics. Where critics express some reservations concerning the validity or applicability of Piagetian theory, that often occurs at the formal operational stage. At least part of this concern derives, directly or indirectly, from Piaget’s use of an idiosyncratic logicomathematical model to describe significant features of the underlying structure of thinking at this stage.
