["The British Journal of Sociology, Volume 73, Issue 3, Page 623-642, June 2022. ", "\nAbstract\nThe developing discourse around social investment and impact investing makes strong claims regarding the possibility of both furthering one's own interests while simultaneously acting for the benefit of others—“doing good and doing well”. Such claims are central to UK‐ and US‐centric attempts to reform capitalism in the face of multiple global crises. This article uses Foucault's writing on (neo)liberal governmentality to analyze a particular manifestation of the logic of “doing good and doing well”: the attempt to build a market for social investment in the UK between 2010 and 2016, a project closely related to the development of the broader impact investment movement. Building on a close reading of Foucault's writing on the role of self‐interest, it is argued that two incompatible versions of social investment are present within the development of the market: one (the “innovative version”) that assumes purpose and profit are fully compatible, and one (the “principled version”) that assumes it is important to maintain a boundary between them. The relevance of these findings and the approach used is discussed in relation to the social studies of market, and ongoing efforts to develop a critique of “doing good and doing well”.\n"]