“Grace does not destroy nature, it perfects it” is a quote from Thomas Aquinas, one of the most influential theologians and philosophers in the Christian tradition.
This quote expresses a central concept in Aquinas’s thought. He believed that both nature and grace are aspects of God’s creation and therefore, they work together, not against each other. In his view, God created nature, and nature is good because it reflects God’s goodness. Grace, in Christian theology, is generally understood as the unmerited favour or love of God, and it’s seen as a transformative power that helps humans to act in accordance with God’s will.
When Aquinas says that “grace does not destroy nature, it perfects it”, he means that the infusion of divine grace doesn’t negate or eliminate our natural qualities or inclinations. Instead, it completes, perfects, and elevates them, helping us to use our natural capacities in the highest and best way possible – that is, in accordance with the divine will. In other words, grace helps nature to fulfil its potential, leading it towards its ultimate purpose or end, which for Aquinas would be union with God.