Thomas Aquinas: The Existence Of God

In Summa Theologiae 1a.2.3, Aquinas writes that ‘the existence of God can be proved in five ways’, concluding each of his five arguments with a form of the phrase ‘this everyone understands to be God’. Critically examine the limits and critically assess the legitimacy of Aquinas’ leap from the proofs/ways to the existence of God.

This question is loaded with an assertion that Aquinas' arguments conclude with a 'leap' to reach 'God' in each of the five arguments presented. In response to this, we will seek to dissect the intention of the passage in the context of the whole Summa Theologiae. With this in mind, we will demonstrate that while these arguments appear independent of each other, when taken together they convey a sense of what the

What does proof mean in this context? The Dominican scholar, Fergus Kerr, notes "the famous 'five ways' of demonstrating God's existence...are not an attempt to refute atheism but an effort of faith seeking understanding of itself" . Velecky, himself a laicized Dominican friar, similarly does not think that these arguments demonstrate God's existence as "none of the five arguments ends with the logical conclusion about God's existence" . Since for Aquinas "God's existence is neither self-evident nor purely a matter of faith" , these proofs concern whether "saying God exists" ('deum esse') is possible - not whether God exists ("dei esse") . Brian Davies illustrates the distinction as the difference between knowing "that there is something stopping the door from opening [and] knowing what it is" . The proof presented by the five ways simply the possibility for humans to speak about God existing. The apparent leap in logic is due to a misunderstood and exaggerated understanding of the five ways purpose. While these arguments end with the phase 'and this everyone calls God', later Aquinas does simply say "and this one is God" (ST 1, 11, 3); this distinction in language chosen supports this distinction between being able to say God exists verses proving that God

However as God is not self-evident (ST 1, 2, 1), there ought to be a means to come to understanding God. The Summa Theologiae aims to bring this understanding about by a gradual and systematic approach to doctrine. However, Aquinas is clear that faith is necessary to reinforce even those things that can be grasped by reason alone, therefore to obtain "knowledge of God, free of doubt and uncertainty, it was necessary for Divine matters to be delivered to them by way of faith, being told to them, as it were, by God Himself Who cannot lie" (ST 2/2.2.4).

With his deliberate and calculated approach to the Summa Theologiae, it would not be unreasonable to go further and suggest that this perceived leap does itself provide a precise function in his institutional scheme. Dionysius explained that "the most goodly knowing of God is that, the which is known by unknowing" . Aquinas does not aim to exhaust the mysteries of the Divine for "unless there is a sense in which it falls silent before the mystery of God, theology cannot speak of him" . Or, to put it in his own words, "we cannot know what [God] is, but only what He is not" (ST 1.3.