This article takes a fresh look at the intellectual context of the poor law in Britain and Ireland from the 1830s to the 1930s, and is focused on the different conceptions over time of the ‘service user’ as agent (drawing on Le Grand) in relation to a fundamental contrast between social theory which is ‘non-idealist’ and ‘idealist’ (drawing on Harris). It first examines the ideas of liberal tories, rather than Benthamites, in remodelling the poor law in England and introducing it to Ireland in the 1830s. Second, it explicitly draws a contrast between idealist and non-idealist social thought, relating it to the idealist nature of both the majority and minority reports on the poor law of 1909 and to the non-idealist thought of Spencer and the earlier discussion. The subsequent dominance of idealist thought in social policy theory and practice is then reviewed, considering Titmuss on agency, the ‘rediscovery’ of informal care in the 1970s as evidence of a shift to the non-idealist perspective that people can act as rational agents for their own well-being, and the resurgent influence of idealist thought on ‘New Labour’. The article concludes that links identified between ideas of agency and types of social theory since the 1830s enhance our understanding of debates today.