Proof Through Gradation

We're covering St. Thomas Aquinas's 5 proofs for the existence of God. Here's the fourth: Gradation.

There are different levels of existence and being. Look at inanimate matter, like minerals. They represent a basic level of existence, they are merely there. The next level up is plant life- simple, but alive. Farther up is animal life-capable of life and reproduction, but also possessing an awareness based on senses. Animals can detect things with their ears, noses, mouths, and eyes.

Next on the ladder is human life, capable of the animal properties, but also possessing the power of rational reasoning. Humans also have free will.

Up the hierarchy, the next level of beings is angelic - pure spirits with no bodies. Angels have a superior form of existence to humans, since angels possess all the knowledge they will have at once, and have much more powerful minds than mortals. With no bodies, they feel no pain, hunger, thirst, sickness, or sleep. They are immortal and have power over the world as pure spirits.

The final level of existence is a Supreme Pure Being that has no beginning or end. St. Thomas believed that this Being was God. Like angels, God has no body, but is composed of a pure spirit. However, there is a difference: angels have a beginning, since God created them. Also unlike angels, who have limited knowledge and power, God has infinite power, meaning that he's omnipotent; he posseses infinite knowledge (omniscient); and he's everywhere (he's omnipresent).