St. Thomas Aquinas's holiness did not flower alongside his endeavor as a theologian or in isolation from it. Rather, it was a fruit of his practice of theology and the asceticism proper to magnanimous souls who dare to examine the mystery of God. Theological affectivity--charity present through a living faith--is necessary for an authentic practice of theology. The experience of God, which is essential to the mystical life, is at the heart of Aquinas's...