Saint Thomas Aquinas: Philosophy and Theology
Saint Thomas Aquinas: Key Philosophical and Theological Concepts
The Five Ways: Proofs for the Existence of God
First Way: Argument from Motion
It is evident from our senses that the world contains things that move. Everything that moves is moved by another. To be moved requires potentiality, and to move requires actuality. It is impossible for something to be both mover and moved in the same way simultaneously. Therefore, it is necessary to arrive at a first mover, a pure act, that is not moved by anything else. This is what we understand to be God.
Second Way: Argument from Efficient Cause
We find that in the sensible world, there is an order in the chain of efficient causes. It is impossible for something to be the cause of itself. It is also impossible for the series of causes to regress infinitely because there are always subordinate causes, and if a cause is removed, the effect is removed. Therefore, we must posit a first efficient cause, which is God.
Third Way: Argument from Contingency
We observe things in nature that can either be or not be, as beings are born and die. It is impossible for these things to always exist, and it is possible that at one time, nothing existed. If there had been no being, nothing would have come into existence, and now nothing would exist, which is false. Therefore, not all things are contingent; there must be a necessary being, which is God.
Fourth Way: Argument from Degrees of Perfection
We observe in nature things that are more or less true than others. The terms “more” and “less” are applied based on their proximity to the maximum. Therefore, there must be something that is the ultimate truth, the cause of goodness, and all the perfections of beings. This is God. Although this does not occur via the principle of impossibility, it is clear that if there were not a perfect being, we could not attribute any perfection to anyone, as there would be no referent.
Fifth Way: Argument from the Order of the World
We see in nature beings without knowledge that act for an end. What lacks knowledge cannot tend to an end unless it is guided by someone who possesses knowledge. Therefore, there is a highly intelligent being who directs all things. This is God. If there were no ordering intelligence, it would be impossible to have order in the universe.
The Moral Philosophy of Saint Thomas
The only good is in God, and there are two possibilities: to live in God or to live against God. Saint Thomas argues that what people understand as good (e.g., money) are not goods in themselves but distorted reflections of the authentic good (God). He also connects the search for good with the pursuit of happiness. Saint Thomas speaks of beatitude, and this happiness is reserved for those who live in God. This notion attempts to define who is good and who is evil. Here arises the notion of evil with appearances, reflecting the truly real (God).
Positive Natural Law
Created by humans following the precepts imposed by natural law. Reason introduces good as something that we all pursue and evil as something to avoid. Thus, the order of moral precepts correlates to our inclinations and constitutes the contents of natural law:
- All humans, as substances, seek to preserve their existence and being.
- Humans have an inclination toward procreation and the care of children.
- Humans tend to seek truth and live in society.
The Doctrine of Truth in Saint Thomas
Faith and reason each have their truths, but they are aspects of a single truth. Saint Thomas identified natural reason with supernatural faith. The preambles of faith are used to reach the articles of faith; these cannot be proven. The articles of faith belong to faith, while the preambles of faith belong to both faith and reason. These articles are self-evident and can only be known by the perfect and infinite understanding of God. Human understanding is finite and imperfect and cannot fully understand the articles of faith. The proofs of God are an example. The Bible gives information about the existence of God. The notion of God’s existence is not against reason; reason can help to understand and demonstrate the preambles of faith and understand the articles of faith.
Political Approach of Saint Thomas
Saint Thomas argues that spiritual power should be at the head, with temporal power subordinate to it. God is the author of creation and has not created it in just any way but in a hierarchical fashion. There are two hierarchies:
- The ontological hierarchy, which has to do with being and perfection (God).
- The axiological hierarchy, which has to do with values.
Natural law is the reflection of divine law in creation. When we speak of natural law in the Middle Ages, it refers to the ontological hierarchy. Positive law reflects the rules for humans in society, so that these are just, they should conform to natural law but are not perfect.
“Per se” and “Quoad Nos” (To Us)
Per se (in itself) evidence will only be understood by infinite and perfect understanding. Quoad nos (to us) evidence can be understood by our imperfect and finite understanding. Only God’s understanding can fully grasp per se evidence, not ours.
Theory of Knowledge of Saint Thomas
Saint Thomas made changes, but we will consider only two:
Abstraction: Saint Thomas conceives of abstractions, but for Aristotle, it is the way of understanding the subject, and where that form is a concept akin to the concept of essence. What makes the concept an essence is that it defines the features common to all the essences of the same group. Saint Thomas said that our senses are able to perceive the universal but common features in particular that can be represented by an understanding through concepts.
The Principle of Individuation: In Saint Thomas, the question is how individuals are what Aristotle called substance. Substance is formed through the raw material. Aristotle says that form is used to define the universal. Saint Thomas argues that the difference between individuals of the same genre comes from the field, while the differences between individuals of different genres come from the form.