Aquinas’ Philosophy: Reality, God, Knowledge, and Ethics
The Problem of Reality: Metaphysics
Aquinas accepted Aristotle’s conception of reality, but several of his theories claim that God is the creator of the universe and is therefore a necessary being, as opposed to beings that are created by him, which are contingent. Contingent beings are those who may or may not exist, while God is necessary, as there cannot be non-existence. In addition, in contingent beings, there is a distinction between their essence (their universal definition) and their existence (whether they really exist or not), but in God, as a necessary being, his essence implies his existence. The essence is the power of being (possibility), and existence is the act of being. Aquinas also establishes a hierarchy of beings because there are varying degrees of perfection. The potential of a being’s essence and its similarity (participation) with God’s will be more or less perfect according to its resemblance to a greater or lesser degree to God.
The Problem of God: Theology
Saint Thomas affirms God as pure act, necessary, immutable, and perfect, whose activity is thought itself, as Aristotle says. However, Aquinas’ God is a creator God and, therefore, knows the world, thinks of himself, and cares for his creatures. But Thomas understands that the existence of God is rationally problematic, and therefore a fundamental task of reason is the demonstration of the existence of God because if it is self-evident (because God is necessary), it is not clear to us because our reason is limited and we do not know the concept of God, his essence being unknowable to human reason. Saint Thomas says it is only possible to demonstrate the existence of God using the demonstration a posteriori, where we start from the knowledge of the effects, the creatures, to demonstrate the existence of their cause, God. Aquinas demonstrates the existence of God in five ways. The first starts from the movement of beings to affirm the existence of God as the unmoved mover. The second starts from the existence of caused causes to establish the cause of God as uncaused. The third starts from the existence of contingent beings to affirm God as necessary. The fourth (Platonic influence) starts from the existence of degrees of perfection in people to affirm God as a perfect being. The fifth starts from the orderly behavior of natural beings to affirm the existence of God as ordering intelligence. This ordering is done through the imposition of the eternal law, the law governing physical irrational beings, and men with the natural law, the moral law, which allows for their freedom. So God turns out to be the unmoved mover, first cause, creator, necessary being, perfect being, and computer in the universe.
The Problem of Knowledge: Epistemology
The essence of God is unknowable to human reason, as the object of study itself and human understanding are natural beings, our understanding of materials being joined to the sensibilities. Saint Thomas distinguishes two different sources of knowledge: reason and faith. Human reason imperfectly knows God’s essence and has limits that may be extended only by faith. Reason and faith have their own specific contents, but also common content. For Saint Thomas, reason and faith are autonomous and independent; there can be no contradiction between the contents of both and they must help each other: reason helps to build faith in theology, and faith helps reason as a criterion of extrinsic negative findings.
Saint Thomas, in connection with the claim that rational knowledge develops from sensory perception through abstract universal concepts, states that the agent intellect abstracts the common characteristics, knowing the universal concept, and understanding these universal concepts can be applied.
The Problem of Man: Anthropology
Understanding, the rational capacity, is the power most typical of the human soul, which is its essence and the principle of life. Man is, for Aquinas, the substantial union of the body (mortal) and the rational soul (which exists, immortal and incorruptible). The human soul has three faculties:
- Vegetative, allowing food and development
- Sensory, allowing sensations gifted by the senses, desires, and movements
- Rational, enabling thought
The Problem of Morality: Ethics
Saint Thomas proposes a teleological view of human life, stating that with the development of our soul, we get perfect happiness, man’s final end, to which it tends. Perfect happiness is given through the contemplation or knowledge of the supreme being, God, the first cause of all beings. In man, he asserts the existence of natural law, the way God has imposed on men the eternal law, respecting their freedom. Synderesis is the habit whereby we tend to carry out the precepts of natural law and spontaneous natural tendency. Natural law contains provisions that are based on human nature and should govern our behavior. Natural law has several provisions that are based on one principle: the duty to develop the very essence, doing good and avoiding evil. From this are derived three primary precepts that guide the development of the three faculties of our soul:
- The duty to preserve life, developing the vegetative power
- The duty to procreate and raise children, developing the sensitive faculty
- The duty to respect social justice and to seek the truth (the knowledge of God), thus developing the rational faculty
The content of natural law (its provisions) is clear (all can learn it), universal (applies to all human beings), and immutable (never changes) because it is implicit in the human essence. Conscience is the rational reflection whereby we deduce from the general precepts about specific secondary precepts for real situations. These are almost always the same for all men, except in certain cases and for various reasons, or when for some reason it is impossible to observe a particular provision.
The Problem of Society: Social Theory
The rational faculty of man can only thrive in society, and man is, to Saint Thomas, by nature a social being. The precepts of natural law are too general and should be concretized by positive law, the laws governing a given society, that make possible the fulfillment of natural law in society. Positive laws are conventional and should be a requirement and extension of natural law, respecting the contents of this because if they do not, they will be unfair, and there is a right to disobey. Seeking justice is the junction between morality and law. The best forms of government, according to Saint Thomas, are the monarchy, the aristocracy, and democracy, while respecting natural law in positive law.