St. Thomas Aquinas: Proofs of God’s Existence & Moral Philosophy
St. Thomas Aquinas on God and Morality
According to St. Thomas Aquinas, the existence of God is a natural knowledge in humans, which can be reached through the proper use of reason and logic, even without Christian Revelation or an act of faith. Reason, when addressed logically and scientifically, can attain certainty of God’s existence, as well as the immortality and spirituality of the soul. These two statements are called, the preambles of faith.
Reason precedes faith and philosophy precedes theology, moving away from the Augustinian view that faith precedes reason. Aquinas rejects the ontological argument of St. Anselm, which is based on the notion of evidence and the metaphysical distinction between essence and existence. This distinction, new in the history of philosophy, states that the essence is the set of notes or properties constituting the being in question, that is, the answer to the question, what is it, while existence is the actualization of the essence of an individual, beginning at the time of onset or birth. In God, there is no such distinction, because His essence is full existence, to exist by itself. His existence is eternal and is the cause of all other beings.
However, human beings find it hard to form the concept of God, which is why there are atheists. Some people even conceive of God in the form of an animal, human, or natural force. For these reasons, the philosopher understands that God’s existence is self-evident, but not for us, as we are limited beings. A thesis, trial, or sentence is self-evident when the predicate is included in the concept of the subject, forming part of its core properties. Therefore, the proposition ‘God exists’ is self-evident because in God there is no distinction between essence and existence, but existence itself is full and complete. However, this is an inconceivable concept for humans. The existence of God needs to be demonstrated by things more accessible to us, even though these things are less obvious.
For this reason, St. Thomas favors a demonstration from effects to causes, ending in the acceptance of a First Cause, which he calls God. Aquinas speaks of a demonstration in the strict sense, or mathematically, five pathways or roads leading to the affirmation of the existence of God. These pathways all have the common structure of causality: every effect has its cause, and it is impossible to have an infinite chain of causes. Therefore, we come to the conclusion of the existence of a first cause, which he called God.
The Five Ways
The first path is that of movement: everything that moves is moved by something else.
The second is that of efficient causality: in the sensible world, there is an order of efficient causes, which cannot be infinite. Therefore, it is necessary to admit a first efficient cause, God.
The third path leads from contingent beings to a necessary being: things can exist or not exist, because they may be produced or destroyed, carrying the possibility of not existing. This means that there was a time when nothing existed. Then, these contingent beings require the existence of a necessary being whose necessity is in itself and is the cause of the necessity of others. This must be called God.
The fourth way is clear from the hierarchy of values found in things. Goodness, truth, kindness, and other values exist in some more than others. This more or less is said regarding a maximum, which is God’s perfection.
The fifth way is clear from the order of things, which, having no knowledge, act upon an end. This order and purpose implies a supreme intelligent being, God.
These five paths are a synthesis of other earlier philosophers, but the originality lies precisely in its structure to demonstrate the existence of God and its main feature: the existence of God is full, it identifies the essence and existence, because it is the higher foundation of other beings, including humans.
Ethics and Politics
In ethics, Aquinas continues an Aristotelian orientation: the end of moral actions is the pursuit of happiness, but this happiness cannot consist in the possession of anything created. Only in God, in the beatific vision, can happiness be found. An act is good if it leads to the ultimate end, and bad if it departs from it.
In politics, Aquinas says that the authority of the rulers comes from God, but the leader must have consultants, representatives of the people. The best form of government is a mixture of monarchy, aristocracy, and democracy. In any event, he recognizes the people’s right to rebel against the rulers when they are corrupted and have not sought the ultimate end of the state, which is the common good. Positive law is an ordinance of reason, directed to the common good, issued by the competent authority, and sufficiently promulgated.