This is a major study of the theological thought of John Calvin, which examines his central theological ideas through a philosophical lens, looking at issues in Metaphysics, Epistemology, and Ethics. The study, the first of its kind, is concerned with how Calvin actually uses philosophical ideas in his work as a theologian and biblical commentator. The book also includes a careful examination of those ideas of Calvin to which the Reformed Epistemologists appeal, to find grounds and precedent for their development of 'Reformed Epistemology', notably the sensus divinitatis and the internal testimony of the Holy Spirit.