Abstract
Calvin holds that the Bible is an authoritative source of the knowledge of God. It imparts that authoritativeness to us is chiefly by the internal testimony of the Holy Spirit, testifying to the truth of the internal cognitive content of Scripture immediately, not by reference to Church Councils or the Pontiff. But there are also external arguments for the authority of Scripture, which are less certain and which may have an apologetic use. Calvin's discussion of these matters raises epistemological issues to do with self-authentication, certainty, knowledge, evidence, doubt, and epistemic circularity, which this Chapter considers.