ABSTRACT
This chapter faces a difficult task: that of showing the relationship between subjective and objective knowledge of mathematics in social constructivism. It skirts the edge of psychologism, and it needs to conjoin two different languages, theories and modes of thought that apply to two different realms, the subjective and the objective. Suitably elaborated, the social constructivist view also provides an account of the development of knowledge of the world of people and social interaction, and the acquisition of language. The very mechanism which improves the fit of subjective knowledge with the world also accounts for the fit with the social world, including patterns of linguistic use and behaviour. The relationship between subjective and objective knowledge of mathematics is central to the social constructivist philosophy of mathematics. According to this philosophy, these realms are mutually dependent, and serve to recreate each other.
