The development of the novel of ideas has at times been closely related to the development of another literary form that emerged out of the social and political transformations of nineteenth-century Britain: the historical novel. With a glance back at a prototype of both forms – the fiction of Sir Walter Scott – this chapter moves on to discuss the work of one of Scott’s unlikeliest yet most significant inheritors, the Scottish socialist and feminist novelist Naomi Mitchison. It argues for Mitchison as one of the foremost twentieth-century practitioners of the historical novel as novel of ideas, focussing on The Bull Calves (1947), which she wrote during the Second World War, and which drew on her own family history as well as the wider history of Scotland’s complicated political status in the aftermath of the 1745 Jacobite rising. Mitchison’s most important contribution to the twentieth-century novel of ideas, the chapter concludes, was to forge a new kind of historical fiction which took seriously the dialectical relationship between conceptual and linguistic change.