A Brief Explication of the De Ente Proof
St. Thomas Aquinas is probably most well known for his “Five Ways”, Quinquae Viae, found in the Summa Theologiae (ST I, q. 2, a. 3). However, these arguments are frequently misunderstood because they are often presented totally removed from their relation to the rest of Aquinas’s corpus, which makes them appear much weaker than they actually are. For example, Aquinas’s First Way is often displayed as being nothing more than a reiteration of Aristotle's argument for an unmoved mover in Book 8 of the physics, however this fails to capture the novelty of the First Way, and the other Five Ways in general (Physics 251a8-251b10). The actual power of these arguments comes from Aquinas’s metaphysics of esse as presented in the De ente et essentia . This power is mostly clearly observable in chapter 4 of the De ente et essentia because this is where Aquinas provides his argument for God’s existence as first cause while explicitly utilizing his metaphysics of esse . In order to fully ...