The paper focuses on the reception of Priestley in Germany, which is remarkable for the huge and assiduous interest it raised in different philosophical milieus. Priestley’s dynamical conception of matter, his explanation of the functioning of the brain, and of the production of material ideas are at the basis of the new form of materialism that develops in Germany in the late 1770s, and which differs completely from the model of mechanical materialism Germany was used to in earlier decades. Indeed, (...) the German reception of Priestley’s ideas begins surprisingly early, just one year after the publication of his edition of Hartley’s Observations on Man (1775), and traverses the two final decades of the eighteenth century with a considerable number of reviews and references in the main philosophical journals and works of the time. In 1778, his introduction to the Observations was translated into German and presented in the form of a manifesto of a new materialistic philosophy compatible with the claims of morals and religion. Within a few years, Priestley became the unavoidable reference point for the most relevant theological and philosophical discussions concerning the nature of matter and spirits, the place of God, the possibility of human freedom, and the legitimacy of free thinking. (shrink)