This is the essay for the 26th week of the 9th Grade Tom Woods Homeschool. In this blog post, I will be answering two questions. 
The first one is, How does Thomas Aquinas argue for the existence of God based on the concepts of potentiality and actuality? 
The second one is, How did Thomas Aquinas derive two of God’s divine attributes?

Thomas Aquinas tries to prove the existence of God by using logic. He does this by using the principles of potentiality and actuality. Potentiality is the potential of something to do something. For example, a book has the potential to be open, a car has the potential to move. Actuality is when the potential of something is actualized. So when a book is open, it’s potential of being open has been actualized and when a car is moving, then its potential to move has been actualized. No potential can be actualized by itself, it has to be actualized by something else. No car can start itself or a book can open itself. What’s also important is the continued actualization of something. For a car to keep going the engine needs to stay on, if the engine goes off, then the movement stops. This is an essentially ordered series. What this means is that for the car’s potential to move to be actualized, the engine’s potential of being on also needs to be actualized, but the engine’s potential can only be actualized if the ignition is turned on and so on and so on. This series of potentiality and actuality keeps going until it reaches the first member in the series, which is the one that started the series. For the series to not keep going forever and ever, this first member needs to be pure actuality and have no potentiality. This means that the first member has no way to change and is also perfect. Aquinas argues that this first member is God.

Using potentiality and actuality Aquinas also can derive God’s divine attributes. There are 8 divine attributes according to Aquinas and they are simplicity, perfection, goodness, infinity, ubiquity, immutability, eternity, and unity. I will only be covering two of these divine attributes, which are perfection and goodness. I already touched on why god is perfect, but I can now give a more in-depth explanation of why. The reason comes from the Aristotelian principle that something can’t give something else a feature that it doesn’t itself have. An oven can’t open a book because it can’t move. So for God to be the first member of an essentially ordered causal series he needs to possess all features, because he possesses all features God is perfect. The second divine attribute is goodness. What people might say in response to the fact that God possesses all features, is that he also possesses negative features like blindness, weakness, stupidity, etc. Aquinas argues that the negative features aren’t features. He says that they are privations, which are a lack of a feature. So blindness is a lack of sight, weakness is a lack of strength and stupidity is the lack of intelligence.