The role of professions in the development of advanced industrial societies has long been recognized – for example, by Harold Perkin. However, the focus has been on the higher professions. Other professions have usually been dealt with as imperfect variants, with Etzioni, typically, referring to nurses, schoolteachers, and social workers as “semi-professions”. However, by conceptualizing such professions as social formations in their own right, as ladders of social mobility, and in terms of their permanent social and professional insecurity, it is possible to create a different picture both of their internal dynamics and broader influence. Members of such groups fostered types of social and political activity that became a recognisable feature of developed societies. Moreover, an appreciation of the distinctive ideational and professional contribution of insecure professions can offer a perspective on a number of the major concerns of social historians. The argument is illustrated by reference to the development of such professions mainly in England and Scotland.