Abstract
In a recent paper Ryle introduced the idea of integrating object relations theory and activity theory, a conceptual tradition originated by Vygotsky and developed by a number of Soviet psychologists during the previous decades. A specific aspect of this integrative perspective will be examined, implied in Ryle's paper but not elaborated by him. It is the issue of sign mediation which was Vygotsky's primary contribution to the methodological problems of modern psychology. The aim is to show that object relations theory, especially the work of Winnicott, may bring fresh understanding into Vygotsky's early notions. It is further claimed that, by introducing the contribution of Mikhail Bakhtin and his circle to the notion of sign mediation, the profundity in Winnicott's understanding of the transitional object and of the potential space may be more fully appreciated. At the same time the ideas of Winnicott and Bakhtin will jointly clarify the limitations in Vygotsky's sign conception.