ABSTRACT
Mediation is a theme that runs throughout the writings of Lev Semenovich Vygotsky. In his view a hallmark of human consciousness is that it is associated with the use of tools, especially 'psychological tools', or 'signs'. Mediation also provides the foundation for another of Vygotsky's theoretical goals, namely, building a link between social and historical processes, on the one hand, and individuals' mental processes, on the other. During the last decade of his career, Vygotsky was busy speaking to psychologists, teachers, and professionals concerned with children and adults with disabilities and difficulties, and in doing so he employed a professional language of the psychology and physiology of his day, a form of speaking that qualifies as what M. M. Bakhtin called a 'social language'. From Vygotsky's perspective, the development of mediated action involves a dynamic transition from minimal appreciation of the meaning and functional significance of a sign form to ever increasing levels of sophistication.
