Thomas Aquinas: Philosophy, Theology, and Political Thought
Thomas Aquinas: Proof of God’s Existence
To prove the existence of God, Thomas Aquinas proposed several demonstrations, which he called “tracks.” Some of these are:
- The Argument from Motion: Things are in motion, and everything that moves requires a mover to initiate it. This first unmoved mover is God.
- The Argument from Efficient Cause: All existing beings have an efficient cause that created them. This uncaused cause is God.
- The Argument from Necessity: Since everything around us exists and then ceases to exist, it follows that all of this is merely possible. The necessary being is God.
- The Argument from Gradation of Being: All people are able to judge events and actions, qualifying them as better or worse. This is possible because there is a supreme good, which is God.
- The Argument from Design: Everything that happens is for a purpose, and must have been designed by a superior mind, which is God.
Thomas Aquinas’ Metaphysics
In his metaphysics, Thomas Aquinas asserts that God is not self-evident to all beings. To prove this, he reasons and analyzes the difference between the being of God (the creator) and humans (created creatures). God is the reason for the existence of other beings. He identifies essence as that which defines an entity, composed of matter and form, shared by all members of the same species. This is identified with the Aristotelian concept of potentiality. Existence is that by which the essence exists, identified with the Aristotelian concept of actuality. Humans are contingent beings; their essence is not identical with their existence. They are beings with potentiality. God created these creatures and the universe, so the universe is not eternal. Saint Thomas uses the theory of potentiality (qualities that beings can develop) and actuality (qualities that have become realities) to explain movement. He uses the hylomorphic theory for the formation of beings and the causes of being to explain their origin. Therefore, all things that move are moved by something, and it is impossible for a being to be in actuality and potentiality at the same time.
Anthropology
The conception of the human being follows Aristotle’s hylomorphic theory. The human being is understood as a substantial unity composed of matter that has a form called the soul. There are three kinds of soul: rational (characteristic of humans), sensitive (of animals), and vegetative (of plants). Saint Thomas maintains that the soul is immortal.
Thomas Aquinas’ Theory of Knowledge
Saint Thomas distinguishes two kinds of knowledge:
- Sensitive Knowledge: Humans grasp reality through the senses. Thanks to the imagination, an image of reality is formed in the human mind, which Thomas called a “phantasm.”
- Abstract Knowledge: Understanding performs two operations: abstraction (by the intellect) and the formation of universal concepts (by the agent intellect). Human beings can only know sensible reality. Divinity is beyond the scope of their senses. However, there can be indirect knowledge of God.
Thomas Aquinas’ Ethics
Following Aristotle, Thomas Aquinas adopts a eudaimonistic ethic and recognizes that all natural beings tend toward an end, which in the case of humans is happiness.
He distinguishes two kinds of virtues: theoretical and ethical.
- The Theoretical Path: Also called intellectual or contemplative, it develops the theoretical virtues. It aims to achieve happiness in the beatific contemplation of God.
- The Path of Habit: This path develops moral virtues and involves acquiring the habit of choosing good actions at all times.
This ethic is based on natural law. When deliberating on a matter, reason discovers that there are moral principles inherent in nature, an unwritten, universal, and unchanging law. Natural law refers to the purposes for which human beings are created, imprinted in their nature in the form of tendencies and habits, and the fact that human beings can behave rationally and choose the appropriate means to achieve those goals.
Politics
Politics is an extension of the laws of nature. Human beings are social by nature and have a transcendent purpose. The state should enable humans to achieve their supernatural end. The individual serves the community. Saint Thomas believes that political and religious power are independent and compatible, but temporal power is subordinate to religion and promotes compliance with natural law, thus distancing himself from Augustine’s political Augustinianism. State sovereignty is limited by natural law and the common good. If there is tyranny, there should be a law-abiding democracy. There are bad forms of government (democracy, demagoguery, oligarchy, tyranny) and good forms.