Thomas Aquinas: Philosophy, Theology & Ethics
Thomas Aquinas
1. Faith and Reason
The spread of Aristotelian thought in Europe challenged the Augustinian understanding of the relationship between faith and reason. Thomas Aquinas’s novel approach defended a theory of harmonious coexistence, where faith and reason could offer different perspectives on the same truth. Latin Averroism and the theory of double truth represented attempts to defend the autonomy of reason. Aquinas’s approach rests on three principles:
- Reason and faith are distinct faculties of knowledge, each with its own methods.
- Certain truths are accessible through both faith and reason; these constitute natural or rational theology.
- Faith and reason cannot contradict each other. While apparent contradictions may arise, true contradiction is impossible as truth is singular.
Aquinas’s approach aimed to maintain the autonomy of reason while avoiding extremes. However, this autonomy remained limited, as reason was ultimately subordinate to faith and recognized as a source of knowledge only within the boundaries of Christian doctrine.
2. Metaphysical Thought
Aquinas’s metaphysics synthesized Greek philosophy and medieval Christianity, incorporating both Aristotelian and non-Aristotelian principles.
- Essence and Existence: A cornerstone of Thomistic philosophy, this distinction posits that in any substance, essence (what a thing is) can be differentiated from existence (that a thing is). In God, essence and existence are identical, as God is the being whose essence is to exist. This principle distinguishes created beings from the necessary being (God).
- Exemplary Causality: This Platonic principle, interpreted through a Christian lens, asserts that God is the exemplary cause of all creation, serving as the model for all things.
- Principle of Participation: Related to causality, this principle suggests that creatures participate in some way in their creator.
- Hierarchy of Being: This principle introduces a hierarchical view of the universe, where beings closer to God are more perfect and resemble Him more closely.
3. Theology: The Five Ways
Aquinas believed that God’s existence is self-evident in itself but not to us, necessitating proof. Rejecting ontologism, which sought to demonstrate God’s existence without evidence, Aquinas advocated for a posteriori arguments (reasoning from effects to causes). He argued that demonstrating God’s existence must begin with the empirical world due to its accessibility. Aquinas developed five rational arguments, known as the Five Ways, to prove God’s existence. His rationale for employing a posteriori arguments stemmed from the belief that we must proceed from the simplest to the most complex. The empirical world, perceived through the senses, serves as the starting point, while God, a non-empirical reality, is the ultimate goal. The Five Ways follow a common structure:
- Starting Point: An empirical fact observable through the senses.
- Principle of Causality: A principle of natural philosophy used to develop the argument.
- Rejection of Infinite Regress: Every effect has a cause, leading to another cause, and so on. An infinite series of causes is impossible; there must be a first cause that is the source of all existence.
- Conclusion: The first cause is identified as God. Each Way attributes a different divine characteristic.
The Five Ways not only aim to prove God’s existence but also provide insights into God’s nature.
4. Anthropology
Aquinas defended a dualistic view of humanity, attempting to reconcile Greek thought with the Christian understanding.
- Body-Soul Union: Aquinas emphasized the significance of the body-soul union, rejecting the notion of the soul’s mortality. He viewed the soul as the form of the body, making the human being a unified entity.
- Faculties of the Soul: The soul possesses distinct faculties or powers, including higher powers (unique to humans, such as intellect and will) and lower powers (shared with other animals, such as sensation and appetite).
- Immortality of the Soul: Upon separation from the body, the soul endures, retaining its higher powers, which are not dependent on the material body.
- Theory of Abstraction: Aquinas explained the origin of concepts through a process of abstraction. The senses perceive a real entity, and the data is stored in memory as images. The intellect then acts upon these images, abstracting common features and eliminating individual differences, resulting in the formation of universal concepts. These concepts are then applied to images through a process of judgment.
The roles of knowledge (abstraction and generalization) are complementary. The intellect primarily knows the universal, not the individual, which it knows indirectly through the application of universal concepts.
5. Ethicopolitical Thought
Aquinas’s ethics and politics were heavily influenced by Aristotle. He defended a hedonistic (happiness as the ultimate end of life) and teleological (happiness as a goal achieved through the development of natural human capacities) ethical framework.
- Happiness: True happiness, according to Aquinas, consists in achieving the highest knowledge, which is the knowledge of God. This ultimate happiness can only be attained in eternal life and is distinct from the imperfect happiness achievable in earthly life.
- Laws: Aquinas identified three types of laws governing the universe:
- Eternal Law: The divine order of God’s intelligence, according to which God governs all creation. Only human beings are aware of the laws governing their behavior.
- Natural Law: The divine order inscribed in nature. Human beings possess natural inclinations that impose rules of conduct. These include self-preservation, procreation, and the pursuit of truth and social life.
- Human Law: Positive laws enacted by human authorities to promote the common good and guide human behavior in accordance with natural law.
These inclinations give rise to fundamental moral precepts that guide human action towards the ultimate goal of happiness.