This paper starts by exploring the relevance of Bernstein's work on vertical and horizontal discourses and the constitution of professional knowledge for conceptualisation of the knowledge needed for teaching practice. Building on arguments for the differentiated nature of knowledge, and drawing on the work of Winch, Young and Muller on expertise, and the sociology of the professions, this paper advances a conception of teaching as a "specialised professional practice" that requires the support of particular socio-epistemic arrangements and conditions embedded in professional communities. Prevalent notions of teaching and teacher education that find favour in some European countries are examined in the light of these arguments, with particular reference to recent reforms in England.