St. Thomas Aquinas (1225-1274) is a Doctor of the church. He was an Italian Dominican friar and Roman Catholic priest who was an influential philosopher, theologian, and jurist in the tradition of scholasticism. Canonized in 1323 by Pope John XXII, Aquinas was the foremost classical proponent of natural theology and the father of Thomism.The late John A. Oesterle was assistant chairman of the department of philosophy at the University of Notre Dame (1972-1977) and the editor of The New Scholasticism (1967-1977).

"At the heart of this treatise are the subtle but crucial distinctions St. Thomas draws among the intellect and will, and the intellectual, moral, and theological virtues—establishing at the same time their interdependence. The discussion of prudence, as the bridge between the intellectual and moral virtues, is one of the classic accomplishments of Western thought." —Faith & Reason