was, first of all, a theologian. He easily takes the lead among the systematic expounders of the Reformed system of Christian doctrine. He is scarcely inferior to Augustin among the fathers, or Thomas Aquinas among the schoolmen, and more methodical and symmetrical than either. Melanchthon, himself the prince of Lutheran divines and the Preceptor of Germany, called him emphatically the Theologian.
Calvin's theology is based upon a thorough knowledge of the Scriptures. He was the ablest exegete among the Reformers, and his commentaries rank among the very best of ancient and modern times. His theology, therefore, is biblical rather than scholastic, and has all the freshness of enthusiastic devotion to the truths of Gods Word. At the same time he was a consummate logician and dialectician. He had a rare power of clear, strong, convincing statement. He built up a body of doctrines which is called after him, and which obtained symbolical authority through some of the leading Reformed Confessions of Faith.
[from "History of the Christian Church" by Philip Schaff, D.D. LL. D.]