The Catholic Church holds a nuanced position on Romans 9:18-21, affirming God's absolute sovereignty while maintaining human free will and moral responsibility. The Catechism of the Catholic Church (§§ 600-605) presents salvation as entirely dependent on God's mercy and grace, yet human beings remain free to accept or reject this grace. This mirrors the Thomistic synthesis, developed by St. Thomas Aquinas, which reconciles divine predestination with human liberty through the concept of God's scientia visionis (knowledge of all future free choices).

Catholic exegesis of Romans 9 interprets Paul's discussion of God's election and hardening of hearts (drawing on the potter-clay metaphor) within the larger theological context of divine mercy and human responsibility. The Council of Trent (1545-1563) affirmed that grace is genuinely offered to all, and that human cooperation with grace is necessary. Catholics reject both determinism and Pelagianism, maintaining that predestination is God's foreknowledge of human choices made in grace, not external compulsion.