Asher Sisneros

John Duns Scotus (1265-1308) and William of Ockham (1288-1347) were scholastics whose opinions shattered the framework set by earlier scholastics. They were both nominalist Franciscan Englishmen who taught theology at Oxford and attacked various principles that Thomas Aquinas taught. Their attacks caused people to question Aquinas’ teachings for a time. The dissension they had with Aquinas was rooted in a question regarding the reliability of human reasoning and the reliability of God. 

Thomas Aquinas devoted his life to proving God’s existence by logic. In his book Summa Cuma Gentiles, he elaborated on the Quinque Viae, i.e., the five ways that God’s existence can be proven through nothing but logical reasoning. The unmoved mover argument was one of his proofs. While Aquinas did not deny that men were saved by faith alone, he also believed it was possible to prove to the atheist that God existed on the atheist’s own terms. However, Duns Scotus and William of Ockham disagreed with Aquinas on whether proving God’s existence through reasoning was even possible. 

One of the important differences between the philosophy of Aquinas and the philosophy of William of Ockham stemmed from their difference of opinion regarding God’s divine will. They almost came from opposite approaches. Aquinas borrowed from the teachings of Aristotle and Plato regarding inherent nature. Plato believed that various things could be categorized underneath a label. However, he did not think they were just labels; he thought that similarity and preconceived standards were divine—not bestowed by a divine, but divine themselves. For example, despite the differences between specific dogs, even a young child can recognize them as part of the dog species. Plato called this phenomenon “dogness.” Aristotle accepted the inherent natures that some categories have, but he rejected the divinity Plato attributed to the “forms.” Moreover, Aristotle said that people were called to pursue their unique factor—the thing differentiating them from other species—and that was how to attain happiness and satisfaction in life. The differentiating factor between humans and animals was reasoning and logic. Thus, Aristotle argued that humans obtain the most satisfaction in life through studying reasoning. Thomas Aquinas was an Aristotle sympathizer in this regard. While he was not adamant that philosophy was the only way to attain happiness—he was a Christian, after all—he did believe that fulfillment was attained through doing this under human nature. In other words, he thought it was good for people to pursue what was good for them. As a Christian, Aquinas acknowledged that God never commanded people to do something bad for themselves. However, his starting point was the inherent essences/natures of man and the pursuit of goodness; God was the means of knowing what is good. William of Ockham held to the completely opposite view. He thought God was more than the means of knowing good, God was the definer of good. First, as a nominalist, he rejected the entire concept of natures/essences. Instead, he believed in individual objects. From there, he went on to say that God is not only the means of knowing what is good, but God is the definer of goodness. As such, anything God commands is good or says is good. One example he states is that if God had hypothetically created people, commanding them to hate Him, then hating God would be good. Aquinas completely rejected that, believing that commanding people to hate God would be bad for people and that God making one command for them to hate Him would not change that. It would be, as Aquinas describes, a logical contradiction because loving God is good, and God cannot command what is not good. But as William would say, if God commanded it, it would be good. As one can see, they held fundamentally opposite opinions regarding God’s divine will, which impacted their opinions about reasoning. William would say that apart from faith in God, using reasoning to prove divine truths is impossible; it is only possible with faith. In other words, William would say that truth is defined through divine revelation, while Aquinas would say that truth is defined as the synthesis between human reasoning and divine revelation.  

Similar to William, Scotus was adamant that divine truths—the existence of God, an understanding of the soul’s immortality in heaven, God’s providence, etc.,—could only be known through faith. He rejected the notion that attributes of God or God’s existence could be proven through reasoning alone. As he argued, fallibility is part of human nature, and relying on personal intellect to prove concepts outside of man’s scope is not only hubris, it is also futile. Instead, he argued that divine truths can only be known by the grace of God, through faith, as revealed in the Bible. 

In conclusion, Scotus and William thought Aquinas was wasting time in proving God’s existence through nothing but logic. They believed it was futile because reasoning is fallible. Unlike reasoning, divine revelation is not fallible. By trying to prove the infallible with the fallible, Scotus and William considered Aquinas’ work as nothing more than an impossible proof.