THEOLOGY AND PHILOSOPHY

After completing his education, St. Thomas Aquinas devoted himself to a life of traveling, writing, teaching, public speaking and preaching. Religious institutions and universities alike yearned to benefit from the wisdom of "The Christian Apostle."

At the forefront of medieval thought was a struggle to reconcile the relationship between theology (faith) and philosophy (reason). People were at odds as to how to unite the knowledge they obtained through revelation with the information they observed naturally using their mind and their senses. Based on Averroes's "theory of the double truth," the two types of knowledge were in direct opposition to each other. St. Thomas Aquinas's revolutionary views rejected Averroes's theory, asserting that "both kinds of knowledge ultimately come from God" and were therefore compatible. Not only were they compatible, according to Thomas's ideology, they could work in collaboration: He believed that revelation could guide reason and prevent it from making mistakes, while reason could clarify and demystify faith. St. Thomas Aquinas's work goes on to discuss faith and reason's roles in both perceiving and proving the existence of God.

St. Thomas Aquinas believed that the existence of God could be proven in five ways, mainly by:

1) observing movement in the world as proof of God, the "Immovable Mover";

2) observing cause and effect and identifying God as the cause of everything;

3) concluding that the impermanent nature of beings proves the existence of a necessary being, God, who originates only from within himself;

4) noticing varying levels of human perfection and determining that a supreme, perfect being must therefore exist; and

5) knowing that natural beings could not have intelligence without it being granted to them it by God. Subsequent to defending people's ability to naturally perceive proof of God, Thomas also tackled the challenge of protecting God's image as an all-powerful being.

St. Thomas Aquinas also uniquely addressed appropriate social behavior toward God. In so doing, he gave his ideas a contemporary—some would say timeless—everyday context. Thomas believed that the laws of the state were, in fact, a natural product of human nature, and were crucial to social welfare. By abiding by the social laws of the state, people could earn eternal salvation of their souls in the afterlife, he purported. St. Thomas Aquinas identified three types of laws: natural, positive and eternal. According to his treatise, natural law prompts man to act in accordance with achieving his goals and governs man's sense of right and wrong; positive law is the law of the state, or government, and should always be a manifestation of natural law; and eternal law, in the case of rational beings, depends on reason and is put into action through free will, which also works toward the accomplishment of man's spiritual goals.

Combining traditional principles of theology with modern philosophic thought, St. Thomas Aquinas's treatises touched upon the questions and struggles of medieval intellectuals, church authorities and everyday people alike. Perhaps this is precisely what marked them as unrivaled in their philosophical influence at the time, and explains why they would continue to serve as a building block for contemporary thought—garnering responses from theologians, philosophers, critics and believers—thereafter.