This paper examines overlaps and interplay between the worlds of formal Liberal politics in Britain and the ‘social liberalism’ that was coalescing in activist social work. Focusing on the growing intimacy of Liberal MP Leonard Courtney and East End social worker Kate Potter (the sister of Beatrice Webb) as documented in their personal letters, it illustrates how the liberal-minded reformism of the period had an emotional, subjective dimension. The discussion pays fine-grained attention to how Kate and Leonard expressed their inner feelings and subjectivities in relation to large public topics such as regulatory legislation, the efficacy of voluntarist social work, and concerns about the imperialist tendencies of British foreign policy. By exploring the intimate expressions of these themes in their private correspondence, we gain insights into a private liberalism crafted by hearts as well as minds.