During the 16th century, Europe underwent fundamental sociopolitical changes, which challenged theologians and the church to respond theologically. In light of the celebration of the Reformation and the theme of this conference, this contribution presents Calvin as a ‘public theologian’. To this purpose it is necessary to define ‘public theology’, describe the sociopolitical changes which challenged theologians during the 16th century, and lastly to focus on Calvin’s contribution to the discourse. Because of the vast amount of material that is available, (...) this contribution is limited to Calvin’s first publication, his ‘Commentary on Seneca’s De Clementia’. Calvin’s fundamental understanding of law and justice, as well as his theological engagement with sociopolitical issues, made him a public theologian par excellence. Calvin’s legal training surfaced whenever he addressed the authorities, for instance, when pleading the case of persecuted Protestants. He had a fundamental understanding of issues such as justice and freedom. The rights, responsibilities and obligations of government and people should always remain in balance. Sociopolitical transformation, as experienced in South Africa during the last three decades, requires of theologians to engage theologically with relevant issues. In this, Calvin set a remarkable example. (shrink)