Is God One?

Hello everyone and welcome back to Deeper Waters. We are diving into the ocean of truth and into the deepest ocean that we can, the ocean that is the doctrine of God. We’ve been using as our guide the Summa Theologica of Thomas Aquinas. Those of you who do not have the Summa in your possession can go to and read it online. We are right now studying the Unity of God. Before that, my prayer requests. First, I ask for your prayers for my Christlikeness as I learn to seek the true, the good, and the beautiful. Second, I ask for your prayers for my financial situation. Finally, I ask for your prayers for a third related area in my life. Time to get to our question tonight!

We’ve been going over the topic of unity and tonight, we’re going to bring God into it. Is God one? Aquinas says he is of course. He draws this from a number of points and as we can expect from Aquinas, he will be building on the earlier points he’s established in the doctrine of God.

To begin with, he starts with God’s simplicity. He uses Socrates, the classic example in philosophy, saying that which makes Socrates a man is had by many. Because of that, there can be many men. However, that which makes Socrates Socrates is particular to him. If he was Socrates by what makes him a man, then there could not be many men. However, God is God in turn by his nature being his essence. Because of this, there cannot be many gods and God is one.

This is also shown by his infinity. Because God is infinite, he possesses in himself all perfections of being. This is an important argument and one in fact that I am dialoguing on with a Mormon at this point as Mormon theology is quite lacking. In it, God only differs by degree and not by kind.

Let us then take Thomas’s idea that God has all perfections fitting of being. Let us suppose there was another God who supposed had the same. How would the two differ? Would it be by one having an imperfection? Then the other isn’t perfect. Would one have a perfection the other lacked? Then that other one isn’t perfect. In the end, it would seem that the two would have to be absolutely identical. However, if they are absolutely identical, they are not two but one.

Thomas’s third reason is the order of the universe. For Aquinas, it is easier to have one being the source of order rather than many for even in the multitude, there must be something that makes the multitude one. Oneness is the greater of the two principles. One is the cause of oneness by nature, but there are only many by accident, when there is a division in the oneness. Thus, since there is order in the universe, it follows that that which is the cause of the order is one rather than a multitude. (We will later on see how this works with the Trinity.)

We shall conclude the discussion of God’s unity tomorrow.

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