St. Thomas Aquinas is primarily a theologian. He writes of Sacred Scripture not only as a theologian, but because he is a theologian. As a master of theology his essential textbook was the Bible. From earlier theologians St. Thomas received an understanding of theology, which he shared with his contemporaries and which he in turn was to deepen and strengthen: Sacred Scripture provides the auctoritas of theology. It gives rise to theology, enables and governs it. M-D Chenu has emphasized and demonstrated St. Thomas’ fundamental reliance on the Bible as the foundation of his theological work.
St. Thomas says that ‘the truth of faith is contained in Sacred Scripture.’ He understood that a cursory reading of the text would not reveal this truth very clearly, because it is in Scripture, but ‘diffusely, in diverse ways and sometimes darkly.’ Thomas provides an insight into his own approach to exegesis when he continues: ‘the result is that to draw out the truth of faith from Scripture requires a prolonged study and practice.’ Here we see Thomas the theologian approaching the sacred books in order to draw out carefully from them what faith teaches through them.
St. Thomas served the Church as a ‘Master of the Sacred Scriptures’ (Magister in Sacra Pagina) and, therefore, as J. Mahoney states, the systematic works of Aquinas do not constitute his truly magisterial activity. Mahoney notes the valuable work of H. Denifle who, in his discussion of the text-books of the medieval professors of theology, shows the Bible to be the basic text-book and indicates that ‘the theologian of that day knew no book so well as the Bible.’