Nominalism is a theory that universal abstract ideas such as truth and goodness do not exist because they are not founded upon objective reality. It holds that the words we use for such concepts are merely convenient labels, and that reality cannot be perceived by every human mind through the use of such labels; there are no “universals.”
Complex as it may seem, nominalism has implications for religious faith. If there are no universals, then we cannot really know God, nor can we know about the nature of grace or sin in our lives. We cannot know where we stand with God, as God himself acts arbitrarily; his acts lack an objective nature and do not correspond to human reason. We therefore cannot reliably use reason or logic to discern good from evil, justice from injustice—and therefore we cannot freely and reliably choose what is good.
Martin Luther and John Calvin were heavily influenced by nominalism and its leading proponent, the 14th-century Franciscan scholar William of Ockham. To different degrees, and in opposition to 15 centuries of Catholic thought, they limited the utility of reason in discerning truths of faith and relied instead upon subjective experience and interpretation. Their progeny is the tens of thousands of Protestant denominations, splinter groups, and other independent “nondenominational” churches we have today. Another fruit of nominalism and its rejection of universals is one of the great errors of our time: moral relativism, the denial that any moral absolutes exist.