What is God?' was the question of Thomas Aquinas; 'What is theology for?' is the question of this book. These two concerns are inextricably connected and while the first question can never be adequately answered it is in and through the process of answering it that an answer to the second can be found. The theology that is a sacra doctrina facilitates an ever deepening relationship with the God who is love. This book suggests that this is precisely what Thomas' life as a Dominican friar and theologian witnessed to. Theology is a work of fides et ratio, faith and reason. Hence this book claims that the doing of theology is best understood as not only an academic discipline but also a sacramental, a holy-making one. Far from feeling a need to leave their brains at the door of the church, as contemporary Christians may feel is asked of them, the suggestion is that the development of our intellect is central to human growth into the image and likeness of God. It is a teaching of Thomas Aquinas that the 'ultimate beatitude of a human consists in the use of their highest function ...the operation of the intellect' and so he is a natural partner for this enterprise.