Vermigli did not see predestination as central to his theological system, but it became associated with him because of controversies in which he became entangled. Vermigli developed his doctrine independently of John Calvin, and before Calvin published it in his 1559 "Institutes of the Christian Religion". Vermigli saw God as sovereign over every event, and believed that all things, including evil, were used by him to accomplish his will. Nevertheless, Vermigli did not hold that humans are compelled to good or evil actions. Vermigli held that God had chosen some people for salvation on the basis of grace or unmerited favour alone, with no consideration for any good or evil characteristics, a view referred to as "unconditional election". Vermigli also believed that God passed over the reprobate, those who were not elected to salvation. He saw this as included in the will of God, but different in character from the decision to choose the elect for salvation. Because all people have fallen into sin, the reprobating will of God treats them as by-nature fallen and deserving of damnation. Vermigli's formulation of reprobation as within God's decree while distinct from his saving election was slightly different from Calvin's. Calvin saw predestination to salvation and reprobation as two sides of a single decree. Vermigli's doctrine was to prove more influential in the Reformed confessions. In his early formulation of predestination (ca. 1543–1544), Vermigli drew heavily on Aquinas's "Summa theologiae".