The evolution of the Social Science Association from the National Reformatory Union, the state of public anxiety about the penal arrangements to follow transportation, and the curious relationship of nineteenth-century liberalism and punishment, which has been a focus of historical research in recent years, ensured that penal policy would be a central theme at the Association and encouraged the extension of ‘reformatory principles’ to new types of offender in different situations. This concentration on crime and punishment, and the SSA's vigorous efforts to win public opinion and government to its views, make possible an assessment of the Association's influence over mid-Victorian social policy in general. Its commitment to a set of ideas about criminal behaviour and its eradication, and its role in making policy according to those ideas, meanwhile, call into question recent interpretations of this transitional period in English penal arrangements emphasising the importance of pragmatism and empiricism. The so-called ‘Tory interpretation’ of social reform, in which officials responded with common sense to institutional difficulties in a continuous process of legislation and adaptation, cannot adequately account for the SSA's capacity to foist its long-held views on government, especially the Liberal administration of 1868 to 1874. Nor can it easily explain why men and women with impeccable liberal credentials constructed a category of offender, habitual criminals, and used the power of the state, illiberally, to control them.