James Hutton defended the doctrine of phlogiston in two lengthy dissertations 1792 and 1794. Empirical, biographical and disciplinary contexts jointly explain his position. Observationally, Hutton based his argument on facts about heat, light and the storage of energy, explicitly contrasting them to concerns about weight relationships. Hutton's intellectual development shows how he found these particular problems centrally relevant, and focusing on phlogiston indicates how his better known geology fits into more fundamental thinking about the natural economy. The resonance of Hutton's (...) views with many contemporaries highlights the significance of his views, and suggests how we might reconsider the role of phlogiston in late-eighteenth-century chemistry. (shrink)