Five Ways to Prove God’s Existence
Introduction
Humans possess inherent biases and deduce conduct rules for proper compliance. These trends are classified as substantial, as humans must rationally tend to know the truth and live in society. Living in a society requires legal rules to regulate interactions. Positive law must be compatible with human rational nature and seek the common good.
The Five Ways
Movement as Mobile Performance
It is evident that in this world, some things move. Everything that is moved is moved by another. If what moved is moved in turn, it must be moved by another, and so on. This cannot proceed infinitely. Therefore, a first mover, unmoved by anything, is necessary. This is God.
Experience of an Order of Efficient Causes
We experience an order of efficient causes in this world. Nothing can be an efficient cause of itself, as it would have to be prior to itself, which is impossible. The order of efficient causes cannot proceed ad infinitum. Thus, a first efficient cause is necessary, which is God.
Contingency or Limitation Exists
Some things exist and cease to exist, as some are generated and decay. If all things had the possibility of not existing, nothing would have ever existed. Since something exists now, not all things are possible not to exist. Something must be necessary, and this is God.
Different Degrees of Perfection in Things
We find things in this world more or less good, true, and noble. “More” and “less” imply varying approaches to the highest in each order. Something must be optimally good, true, and noble. What is highest in a genus is the cause of everything under that genus. Therefore, a highest cause of goodness, truth, and nobility exists, and this is God.
The Government of Things
Things lacking knowledge, like natural bodies, act with intent or purpose. However, things without awareness cannot tend toward an end unless directed by something knowing and intelligent. Therefore, an intelligent being directs all natural things to an end, and this is God.
Arguments Against God’s Existence
Some argue against God’s existence based on the notion of absolute infinity. If God is infinitely good, its opposite, evil, could not exist. The existence of evil, therefore, proves that an absolute good (God) does not exist. Another argument suggests that natural processes can be explained without resorting to God, requiring only nature itself and conscious processes like intentions (reason and will), which reside in the human mind.
Thomas Aquinas’s Theory
Thomas Aquinas argues for God’s existence using a biblical quotation from Exodus, where God names himself to Moses: “I am who I am.” Aquinas relies on supernatural theology criteria, although not on authority, in his demonstration. He then presents five “ways” (proofs) for God’s existence. These a posteriori proofs analyze facts in the world to conclude God as their explanatory cause. Aquinas considers demonstrating God’s existence a fundamental task of reason. He raises two questions: Is it necessary to prove God’s existence? And is it possible to prove it?
The first question might seem idle, as it appears clearly necessary to demonstrate God’s existence. However, for Aquinas, the question is not fanciful given the religious and intellectual context of his thought. He lived in a society where religious belief was fully valid, expressed in the conviction that knowledge of God’s existence is naturally imbued in all men. Nevertheless, Aquinas believes God’s existence is not immediately obvious to the human mind and therefore needs proof.
Regarding the second question, Aquinas answers that it is possible to prove God’s existence using the proper procedure: starting from beings in the world considered as effects and reaching God as their cause. This demonstration, going from effect to cause, is called a posteriori. The reverse demonstration, from cause to effect (a priori), is excluded by Aquinas in proving God’s existence.