An Introduction to the Five Ways of St. Thomas Aquinas, Part 2

In the first article in this series, I presented the three objections to the idea that God’s existence can be demonstrated that St. Thomas Aquinas lists in his Summa Theologica.

In responding to these objections, Thomas turns to Romans 1:20, where St. Paul insists that the “invisible attributes” of God can be seen in what He has made. So, we can demonstrate the existence of God by looking to what He has made. Thomas explains that there are two ways to demonstrate something: to begin with the cause and move forward to the effect, or to begin with the effect and move backward to the cause. He then says that demonstrating the existence of God is an example of the second way: since the effects of God are those things we can observe, we can start there and move back to the cause, where we find God.

An example: you’re sitting on a park bench, reading a book and enjoying a brisk autumn afternoon. You hear just in the distance a stirring rendition of Ave Maria on the violin. You listen and enjoy. After the music stops, you look about to see from where the music came. You see a gazebo, now empty save but a music stand and a violin box. Do you know who was playing the music? No. But, you know someone was playing.

We can look at the effect of Creation and conclude backward from the effect to the cause: someone or something created this, just as someone created the strains of Ave Maria on the violin. Can we know all about who or what did the creating? No. The evidence doesn’t reveal enough to say so. But, we can know that someone or something created all of this. Nothing creates itself. Just as there must be a cause for the strains of the violin playing softly the Ave, or the effect wouldn’t have happened and wouldn’t now be heard, so there must be some cause to Creation. Otherwise Creation wouldn’t be here, us included.

Thomas replies to the first objection (that the existence of God is an article of faith), and rejects it. There are qualities of God that can be known by natural reason, by deduction. These qualities of God aren’t articles of faith. Rather, faith is built on top of them. The most basic quality of God we can come to know by natural reason is the fact of His existence. We may not know much about whoever was playing Ave Maria, yet we can certainly know that he or she exists. Just so, we don’t require faith to conclude that God exists, but we see and experience His effects all around us. Reason is sufficient to conclude for the existence of God. Faith, then, is what we believe about the God Whose existence reason demonstrates. Some may be surprised that the Catholic Church doesn't regard the existence of God as an article of faith. Catholic faith begins with our belief that God is Trinity. In a sense, one could say that the Creed doesn't begin with the words, "I believe in God..." but with, "I believe in God, the Father... ." We know that God exists. We believe He is our Father.

The second objection (that we can’t know God’s essence) fails for the same reason. Existence comes before essence. We don’t need to know the essence of a thing in order to know it exists. Rather, just the opposite: we must first have knowledge of a thing’s existence before we can hope to know its essence. Who is responsible for the music we heard in the park? A man? A woman? A maestro? An amateur? We don’t know. But, whoever it is, we know he or she exists. Further investigation can then answer the question of essence.

Finally, the third objection fails for the same reason: we don’t need to know everything about a cause in order to know that the cause exists. The finite can never completely reveal or explain the infinite. But, that isn’t the same as saying that the finite can say nothing about the infinite. The effect can’t always tell us much about whatever caused it. But, it can point to at least one attribute: existence. Again, we don’t need to know everything about a cause, even an infinitely complex cause, in order to know something. What we can certainly know about a cause through its effects is the existence of that cause.

After answering objections to the claim that God’s existence can be demonstrated, Thomas begins the inquiry on whether or not God does, in fact, exist.

Be Christ for all. Bring Christ to all. See Christ in all.