Aquinas' Influences: Philosophy, Theology, and Natural Law

Key Influences on Aquinas

The primary influence on Aquinas was Aristotle. His hylomorphic theory, which posits that the soul and body form a single substance, significantly impacted Aquinas's anthropology and epistemology. This concept addresses the structure and order of beings, applying even to God as the total and ultimate being. Aquinas also drew from Aristotle's understanding of knowledge, which begins with sensory experience and progresses through abstraction to universal knowledge. Furthermore, Aristotle's ethical framework, which emphasizes happiness as the ultimate goal and virtues as the means to achieve it, influenced Aquinas. The study of natural pathology also stems from Aristotle, further developed by Albertus Magnus.

Aquinas was also influenced by Augustine, who explained God's existence through the concepts of the unmoved mover, perfection, and the first cause. Plato's theory of 'participation' also shaped Aquinas's understanding of the relationship between beings. Additionally, Muslim thinkers like Avicenna, who distinguished between essence and existence, and Averroes, who explored the problem of universals, divine knowledge, and the nature of the prime mover, contributed to Aquinas's thought.

His religious background also played a crucial role, shaping his understanding of God. The impact of Aquinas's work is immense, with his thought becoming the official doctrine of the Church for centuries. His concept of natural law, while not exclusive to him, became central to the Church's official position and influenced international law through Thomistic scholars of the Second Scholasticism.

Reason and Faith

The relationship between reason and faith is a key aspect of Aquinas's philosophy. While truths of reason are dependent on revealed truth or faith, the new Averroist philosophical vision of two truths had a significant epistemological impact. The definitive separation of reason and faith occurred in the fourteenth century. Aquinas sought to bridge the gap between reason and faith, considering them both essential principles in Thomistic philosophy. His anthropology emphasizes salvation and is rooted in Greek thought, particularly Aristotle. Aquinas adopted Aristotle's view of humans as occupying the highest position in the hierarchy of beings. However, Aquinas's anthropocentrism is tempered by a theocentrism, with God considered the supreme being. For Aquinas, all beings, including God, are understood through a human lens.

Aquinas believed that humans can reflect on themselves, and through this self-reflection, they become aware of their own humanity. This self-determination is linked to the supreme nature of God. Reason and faith work together to understand God, who is worthy of human thought. This places humans at the center of creation, not just as a creation but also as the center of philosophical thought.

The Faculties of Understanding: Reason and Faith

The human understanding is superior, encompassing both faith and reason. Each has its own distinct field of knowledge, and neither can claim to fully understand the other. Reason is used to establish scientific or philosophical knowledge, based on empirical evidence. Faith, on the other hand, leads to a higher form of knowledge, which is not evident through the senses, such as the knowledge of God.

Reason can also, through analogy to faith, arrive at knowledge of God's existence, the soul, and the immortality of the created world.

Intellectual Knowledge

Intellectual knowledge (scientific or philosophical) begins with sensory experience. Through reason, sensory data is transformed into concepts. These concepts are universal, unlike the particular sensory perceptions. The process of understanding involves:

• Recognizing sensory information from the world.
• Registering this information in memory.
• Abstracting the universal content from the image.
• Formulating the concept.

The understanding universalizes through the formulation of concepts.

Knowledge Through Faith

Knowledge through faith is based on the certainty of God's revelation. Divine grace allows us to understand these truths. This knowledge is more personal and individual, as it is based on the freedom of faith. For Aquinas, the human being is perfect in nature. The imposition of faith is not from God, nor does it force human freedom. Rather, it is a product of grace and individual will.

Philosophy and Theology

Knowing and Reasoning God's Existence

Knowledge of God through reason is achieved by analogy. Data abstracted from sensory experience allows reason to infer the existence of God. The human understanding is open to infinity and has the capacity to know God rationally. This knowledge is necessary for transcendence. The human being's knowledge includes God, who is the ultimate goal. God is the ultimate being, not just a place, but the perfection of human life.

Aquinas also argued that God's existence can be proven rationally through natural human faculties. By contemplating nature, one can conclude:

• Everything that exists has a cause.
• Everything that moves is moved by something else.
• There is a hierarchy of perfection in nature.
• Everything that exists could also not exist.
• All beings in nature act for an end.

Arguments for God's Existence

Based on these principles, Aquinas proposed five ways to prove God's existence:

1. The Argument from Causality: There must be a first cause, uncaused, which is the cause of all other causes.
2. The Argument from Motion: If everything that moves is moved by something else, there must be a first unmoved mover, which is pure act.
3. The Argument from Perfection: If there is a gradation of perfection in beings, there must be an infinitely perfect being, the source of all perfection.
4. The Argument from Contingency: If everything is contingent, there must be a necessary being, which is the source of all contingent beings.
5. The Argument from Order: If all creatures act for an end, there must be an intelligent being that imposed this order on all natural beings.