School leaders are expected to act with integrity, but values are always contested: one person's 'moral purpose' is not the same as another's. Researchers have explored these issues from different angles. One approach focusses on individual leaders, seeking to understand how their values inform their practice. Other work highlights that individual values are only part of the story: values are embedded within professional norms and organisational cultures, while policy and governance frameworks serve to structure and constrain individual agency, particularly in marketised and performative systems. This paper draws on examples from recent research in England to argue that leadership responses to structural constraints should be seen on a spectrum in terms of how far they reflect individual agency and values, proposing four possible categories - 'toxic leadership', 'pragmatic compliance', 'principled infidelity' and 'authentic agency'. It also discusses the question of how values operate at locality and national levels as well as within individual schools and draws the analysis together into a conceptual frame.