How did William of Ockham's nominalism challenge scholastic theology?

William of Ockham's nominalism — the denial that universal concepts like "humanity" or "goodness" refer to real entities beyond individual things — cut the ground from under Aquinas's metaphysical synthesis by severing the necessary connection between reason and divine reality. If universals are merely names (nomina) rather than real forms, then natural reason cannot demonstrate that God is goodness itself or that natural law is grounded in divine nature — these truths become accessible only through revealed will. Ockham's voluntarism and his separation of faith from reason were deeply influential on late medieval theology, the Reformation's skepticism toward scholasticism, and early modern philosophy.