Bodin's Colloquium Heptaplomeres is one of the most important clandestine manuscripts of the early modern period. A fascinating dialogue between seven different religions it tackles some of the main debates of the early modern era. It has long in the historiography been recognised as a key text promoting toleration. However, a close reading of the text and a focus on the way in which it used and debated written authorities (from ancient literature to the Scriptures) directs us toward another crucial issue of the period. Indeed, it challenges and questions received authorities by making use of the dialogue form to question each in turn. Each character relies on the likes of Aristotle, Augustine or the Bible to support their views only to see them challenged by the others through the use of counter interpretations or other authorities. This leads to seeing the text as fundamentally embedded in the sceptical arguments developing at the time, as noted by early modern readers who voiced their concerns about the way in which this text led to doubt, rather than about the potential toleration it promoted