Conclusion: Psalm 14:1G.K. Chesterton once said, "If a thing is worth doing, it's worth doing badly." I hope that I have been able to contribute some small amount to a greater understanding of St. Thomas' proofs of God's existence. Where my eloquence and erudition have failed, I hope the grace of God and the open minds of my readers will supply my defects.
Christopher Hitchens, the famous atheist, opined regarding the Five Ways, that even if they did prove the existence of a deity, that the bulk of the work still lies ahead of us. The proofs show us that a God exists, but they don't tell us anything about that God. To this I make two replies: the first is simply to agree with Mr. Hitchens. After all, St. Thomas' proofs for God are written in Part 1, Section 2, Article 3 of his expansive three-volume Summa Theologica. While the arguments take about a page to articulate, the work of coming to know Who this God is, what He is like, and how we are to relate to Him goes far beyond simply establishing that He exists. Certainly no one could claim otherwise. Atheists, of course, don't deny the existence of a particular God, however, but the possibility of any God, whatsoever.
On the other hand, however, the Five Ways do still reveal a lot about the identity and characteristics of the God which they set out to prove. From the first three Ways, we see that God is omnipotent, the effective power behind all existence and action in this universe. From the Fifth Way, we recognise that God is also omniscient, the supreme Intelligence. The Fourth Way, though, really fleshes things out, for in it we find that God is entirely simple, not made of parts, but utterly One. That unity is infinite, and contains within it intrinsically all perfection—all truth, beauty, goodness, life, justice, wisdom, and all the perfections there are, which, when brought to their infinite fullness are all one, and are God. Perfect, infinite truth is perfect, infinite goodness, which is perfect infinite beauty, which is perfect, infinite Love. As such, the logical conclusion of the Five Ways does not merely bring us to an abstract notion of a deity, but very and specifically close to the deity that the Christians worship.
That God is infinite, moreover, rules out the possibility of polytheism, because if there is more than one God, then they cannot be infinite. There must be some limit that distinguishes them. Since God is infinite, He must be the only God. Anything finite must be a lesser, created being, or simply a fiction. St. Thomas' proofs leave no other option. This is why I said in my introduction, that the atheist's accusation that he and I are both atheists, the only difference being that he believes in one less God than I do, but for the same reasons, is completely false. Because of reason, I believe in an infinite, all-powerful, all-knowing, loving God. No others need apply. My belief in this God is the reason I disbelieve in all the others.
I consider this series on St. Thomas' proofs for God to be a challenge, a dare, even, to those who don't believe in God. This past year, I finished off my Bachelor of Religious Education. One of the last classes I took was a philosophy class. The professor, a Protestant, made the claim that God could not be proven to exist—that we could only take His existence on faith, though a faith aided by reason. All the proofs, according to him, were only probabilities. St. Thomas Aquinas felt otherwise about his Five Ways. He believed that his proofs had the same weight that all logical or mathematical proofs have—and I, for my part, agree with him. Incidentally, so does the Catholic Church, which at the first Vatican Council, made it a binding truth of faith that reason alone could bring a person to a sure knowledge of the existence of God (Canon 1 On Revelation).
So the challenge is this: are you open-minded enough to reason through the arguments, and to follow reason to whatever conclusion it arrives at? What arguments can be brought against the Five Ways? Evolution doesn't work against the Fifth Way, of Design, because the very laws of nature themselves did not and could not evolve! Positing an eternal universe that proceeds from "big bang" to "big crunch" to "big bang" again, as Dr. Stephen Hawking suggests, does not work to overthrow the Second Way, of Causality, since St. Thomas himself held that the creation of the world at a particular moment in time was a matter of divine revelation, but not necessitated by philosophy or reason itself. Since his arguments specifically exclude revelation as a factor, they are equally valid whether the universe began yesterday, or whether it has always existed. Adding millions of years of slow processes to the equation, or removing time altogether from it, does nothing to affect the arguments.
Moreover, each argument stands alone. They do not combine to make a cumulative case for the probability of God's existence. Each demonstrates His existence independently of the others. Cumulatively, they reveal more of Who that God is, as we saw above. But thinking you have shot down one argument still leaves four more that must be dismantled as unreasonable or objectionable in some way in order to escape the inescapable conclusion. That is the challenge. That is the dare.
The thing is, there is a difference between St. Thomas' proofs for God, and a mathematical proof such as 2+2=4. The difference is not in their respective solidity or grounding in reason. The difference is in the subject matter. One has very little personal investment or responsibility in how he lives his life if 2+2=4. There is significantly more to consider about how one's life is lived, however, if God exists. The conclusions are equally inescapable, but they are not equally liked. The only way to avoid the logical conclusions of the Five Ways is to pointedly ignore them or attempt to shout them down. One's lack of faith in God is not the result of a well-reasoned thought process. It is the result of a choice, the choice to close one's eyes, stick one's fingers in one's ears, and shout "Non serviam!"
To quote Chesterton again, "The Christian ideal has not been tried and found wanting; it has been found difficult and left untried."
Prove me wrong!
(Category: Theology Proper: God in general.)