Romanus Cessario, O.P., argues that theology must be joined to conversion, prayer, asceticism, and moral discipline: the theologian’s personal holiness is part of understanding and witnessing to truth. Against self-reliant accounts of theological work and human autonomy, the essay presents Veritatis Splendor as a renewed moral theology centred on the human person’s relation to God. Its historical inquiry traces the post-Tridentine disputes between Dominican and Jesuit approaches to grace and freedom, the rise of Molinism and Jansenism, and Pope Benedict XIII’s 1727 bull Pretiosus, which distinguished authentic Thomism from condemned Jansenist positions. Thomist physical premotion is used to explain how God, as First Cause, moves human beings as genuine secondary causes without destroying their freedom. Sufficient grace is offered to all, efficacious grace moves the will toward good, and human beings can resist grace and remain responsible for failing to use it. The essay rejects both despairing claims that God’s commands are impossible and mechanical accounts that eliminate liberty. Human freedom is instead participated theonomy: reason and will share in divine wisdom. Holiness therefore depends on grace actively received, concrete moral orientation toward God, and a life of continuing conversion rather than speculation about the number of the saved.