An Introduction to the Five Ways of St. Thomas Aquinas, Part 7

The Second Way: The Argument from Efficient Causes

1. We see that there are some things that cause other things.
2. It’s impossible for something to be the cause of itself, for then it would have to exist before it existed, which is absurd.
3. The chain of causes can’t go back forever, for then there would be no first cause and, if no first cause, then no intermediate causes, and no ultimate cause.
4. It’s necessary, then, to arrive at a first cause, not caused by any other, and everyone understands this to be God.

St. Thomas Aquinas, from Aristotle, identified four causes of things: material, formal, efficient and final. Think of a clay pitcher. The material cause of the pitcher is simply what the pitcher is made of, that is, the clay. The formal cause of the pitcher is the form it takes, a cylindrical-shaped container with a spout. The material and formal causes of the pitcher simply make up the matter and form of the pitcher. The efficient cause of the pitcher is that which actualizes it’s potential as a pitcher: the potter, the one who shaped the matter of the clay into the form of the pitcher. At last, the final cause of the pitcher is the purpose for which it was made: to hold and pour out liquids. Thomas developed a demonstration for the existence of God from our experience of efficient causes. As with the Argument from Motion, let’s consider each premise to see if the conclusion is valid.

The first premise seems obvious. A clear example is that of a violinist causing the Ave Maria to come into existence by manipulating the strings of the violin with her bow. Or of the violin maker making the violin in the first place. We see all sorts of examples of some things causing other things. The first premise stands.

The second premise is true. It’s absurd to claim that something can be the cause of its own existence, for how could something exist before it existed so that it could cause itself to exist?

The third premise makes a claim that isn’t so obvious: that the chain of cause and effect can’t go back forever, infinitely. Thomas says that, if there were no first cause, there would be no intermediate causes (regardless of how many) and no ultimate cause. It’s the first cause that gets things rolling. No first cause, no second cause, or third, or fourth, etc, … . Just as in the Argument from Motion, if there were no first mover, there would be no movement at all. So here, if there’s no first cause, then there’s no effect to speak of.

But, why can’t the chain of causes go back forever, to infinity? Here we need to consider a distinction Thomas makes between chains of cause and effect where the effect comes after the cause in time, and chains of cause and effect where the cause and effect happen simultaneously. Consider, for instance, the difference between a violin maker and a violinist. The violin maker exists before his violin exists. When the violin maker is finished, the instrument exists now independently of the maker. If the violin maker should go away, the violin would continue to exist in his absence. Not so with the violinist and her song. If the violinist should stop playing, for whatever reason, the song would come to an end. The song would cease to exist. Thomas argues that the first cause causes the second, and the third, and the fourth, and so on, …, not as a violin maker causes a violin to exist, but as a violinist causes a song to exist. In the case of the violin maker, in a chain of cause and effect where the effect comes after the cause in time, Thomas agrees that it’s possible that the chain of causes goes back forever. He didn’t think it did, personally, but he didn’t think it could be proven philosophically that it didn’t. But, in the case of the violinist, of a chain of cause and effect where the cause and effect happen simultaneously, it really doesn’t matter if the chain goes back forever. Even if it does, there must be a first cause to sustain the song here and now. In this sense, causing something to exist isn’t separate from sustaining or maintaining something in existence. To cause something to exist and to sustain that thing in existence are the same. Given this, it’s clear that there must be a first cause, or nothing would exist. The bow, the strings, the violin – none of these secondary causes has the power, of themselves, to play the song. What’s needed is the violinist. If there’s no violinist, there’s no song to speak of in the first place.

There must, then, be an uncaused cause that’s ultimately responsible for the cause of everything. But, this uncaused cause can’t be a part of everything that’s caused, for then it would be responsible for causing itself, which is absurd. The uncaused cause is a being that is not caused by another. It is pure Being. This idea of pure Being is important for Thomas. For every other being, essence and existence are separate. But, for the uncaused cause, essence and existence are the same. The uncaused cause isn’t a Being that merely exists, but a Being whose essence is existence. God doesn’t merely exist. God is existence.

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