Saint Thomas Aquinas was a thirteenth century Dominican monk: Soccio notes that "Dominicans were dedicated to education and to preaching to common people" (Soccio 219). It is this learned quality which permeates Aquinas' approach to building a Christian system of philosophy: Aquinas is usually considered part of a larger medieval intellectual movement known as Scholasticism. Scholasticism represented an attempt on the part of Christian thinkers of the middle ages to justify Christian doctrine so that it was in line with Aristotelian natural philosophy (the medieval equivalent of what we know as "science"). But in the greater sense, Scholasticism was a philosophy that hinged upon the "logical and linguistic analysis of texts and on arguments producing a systematic statement and defense of Christian beliefs," as Soccio puts it (Soccio 222). In other words, there was a strong interest in not only the legalistic codification of Christian doctrine, but also the philosophical justification for the self-contained code itself. Aquinas' approach to religion has sometimes been referred to as "natural theology" because of its analogy to Aristotelian naturalism. Soccio notes that Aquinas' "efforts to prove God's existence begin with appeals to concrete experience and empirical evidence, rather than with revelations or dogma -- an argument style favored by Aristotle" (Soccio 224). In the immediate period before Aquinas, Aristotle had actually been controversial and considered to pose too many contradictions to Christian...
But by Aquinas' day it had become clear that the church needed to account for its own doctrines according to the scientific and systematic philosophies of Aristotle, and Aquinas would fill this gap. Aquinas ultimately produces the "Quinque Viae" or "Five Ways" whereby the existence of God was proven. There had been attempts by Catholic thinkers to provide a proof of God's existence before Aquinas -- such as St. Anselm's "ontological" argument for the existence of God -- but Aquinas felt that Anselm's proof was flawed, and offered the Five Ways as a superior alternative. It may be worth noting that Aquinas does not necessarily present the Five Ways as self-sufficient logical proofs, but more like a logical and Aristotelian definition of terms to establish what is meant by "God." All five of the ways seem obvious reflections of Aristotelian modes of understanding: the argument of the Unmoved Mover and the argument of First Cause both operate by an Aristotelian understanding of movement and change as being prompted by some prior cause, and asserting that only God could present the first element in the chain of causation. The arguments from Contingency and Degree seem more about Aristotelian intellectual categories, and the final Teleological argument seems to…
