Explain St. Thomas Aquinas’s cosmological proof for God’s Existence
In his monumental works, Summa Theologica and Summa Contra Gentiles, Aquinas offered a total of five proofs of God’s existence. The first two proofs begin with an observation about the physical universe. They are called a kind of cosmological argument because they result from a study of the cosmos. Much of Aquinas version of the cosmological argument was borrowed from Aristotle. Aquinas’s cosmological argument consists of his first 2 of the 5 proofs for God’s existence, or the “Five Ways”. His first two ways are two proofs based on logic and observation of nature in proving God’s existence to those who could not accept or believe God on faith alone.
Aquinas’ first way is based on motion. He calls it the most obvious way. This first argument, the Argument from Motion, tries to prove the existence of God as the first mover which is unmoved. Now, it is certain as a matter of sense-observation that some things in this world are in motion. Whatever is in motion, Aquinas states, is moved by something else. So, it is impossible that in the same respect and same manner anything should b
However, this cannot go on to infinity because there would never have been a first mover and, consequently, no subsequent movers. The difference between a "moving" cause and an "efficient" cause is that the moving cause produces another state of something while the efficient cause produces existence. After all, second movers do not move except when moved by a first mover, just as a stick does not move anything except when moved by a hand. Thus, the efficient cause is what brings about the result to be effectively realized as actual. Such a thing would have to be prior to itself, which is impossible. There must always be a cause for any change, a "moving" cause. However, there cannot be an endless string of objects causing other objects to exist so there must be an uncaused first cause. Therefore, if something is in motion, it must have been put in motion by something else, which must have been put in motion by yet another thing, and so on. That is, an object in motion is put in motion by some other object or force. In this, Aquinas means that nothing can move itself. In conclusion, the uncaused cause exists and is called God. Aquinas"tm second way states that no object created itself, or is found to be the efficient cause of itself because if this was the case, the object would have to be prior to itself, which is impossible.