Enlightening the matter of science; The anti-materialistic Enlightenment philosophy of Jean de Castillon (1709-1791)

Castillon was an active scientist and enlightener, who engaged in dialectics with Rousseau, Hume and d'Holbach, adopting their moral, skeptic and materialist discourse in order to show that science was compatible with religious belief and revealed truth. Along the way, he developed a non-reductionistic scientific method. Taking his life and work as a case study, three thesis will be defended: (1) The dichotomous historiography that divides the Enlightenment into radical and conservative strata - hich has become the standard since Jonathan Israel's work - fails to grasp the methodological discussions that were central to Enlightenment discourse. As an alternative, both Castillon's enlightened 'conservatism' and the 'radical' philosophy that he opposed will be approached as exponents of a dialectic of secular theology, which aimed to establish a rigorous scientific methodology that subsumed also moral and religious questions. (2) The mid-eighteenth century critical reaction to materialism forms a missing link in the history of philosophy, connecting Locke, Hume and Leibniz with the later Kantian philosophy. (3) The large-scale notion of 'science', as a general concept unifying different disciplines, only emerged in the mid-to-late-eighteenth century; conceptual innovation and institutionalization interacted to make its development possible.