Thomas Aquinas's Philosophy: Thirteenth-Century Foundations and Core Ideas

Historical Framework of Thomas Aquinas's Philosophy

The philosophy of St. Thomas Aquinas developed in the 13th century, a period representing the greatest flowering of medieval Europe. France served as the cultural and political center, enjoying a stable economy driven by flourishing trade, a stable currency, increasing circulation of precious metals, and the consolidation of papal power. The artisan guild system reached its zenith during this era. Denying the existence of God was dangerous, and the prevailing Augustinian philosophy assumed God's existence.

Sociocultural Context: The Rise of Universities

The 13th century is notable for the appearance and rise of universities, including prominent institutions like Bologna, Oxford, and Salamanca. Although the Middle Ages are often treated as the "Dark Ages," there was a major thrust in fields such as astronomy and medicine. Mendicant orders were founded, notably the Dominicans and Franciscans, who held prominent chairs in these burgeoning universities.

Philosophical Framework: Scholasticism

The dominant educational philosophy practiced in the Middle Ages was Scholasticism, an intellectual movement whose primary intent was to systematize knowledge and reconcile faith with reason. Scholastic thinkers all shared the recognition of two types of knowledge: faith and reason. The Scholastic method had two primary ways of teaching:

• Lectio (reading and commentary on authoritative texts)
• Disputatio (public debate and discussion of philosophical and theological questions)

Key Philosophical Influences on Thomas Aquinas

While St. Albert the Great was his grand master, the main influence on Aquinas's philosophy was Aristotle. Aquinas's thought profoundly integrates Aristotelian concepts, aiming to unite Christianity with empirical Aristotelianism.

Aristotelian Principles Adopted by Aquinas

Aquinas accepts much of Aristotle's thought, admitting the structure of reality and nature through:

• Act-Potency concepts
• Accidents and Substance
• Matter-Form theory
• The Theory of Four Causes

In theology, he accepts the demonstration of God's existence based on motion (the First Way), understanding God as the Unmoved Mover and Pure Act. In anthropology, he supports the hylemorphic conception of man and the substantial union of soul and body. In ethics, he subscribes to the ultimate end in happiness, asserting that human nature is the foundation of moral law.

Non-Aristotelian Influences

Aquinas was also influenced by Augustinian Platonism and Neoplatonism, especially in areas where Aristotelian philosophy was incompatible with Christianity. Examples include:

• The immortal soul
• The idea of participation
• The principle of the degrees of being and perfection

A fundamental principle of his philosophy is the distinction between essence and existence, a concept also explored by the Arab philosopher Avicenna, and the concept of natural law. He also drew from Stoic philosophy and, of course, the fundamental texts of Christianity and the Church Fathers (primarily St. Augustine), as well as the thought of Averroes, whose doctrine of double truth, among others, he categorically rejects.