Christopher Martin's Examination of the Fifth Way #1

The Fifth Way of Thomas Aquinas is one of the most misunderstood arguments for the existence of God. Primarily because of the Intelligent Design movement making such a loud racket that nobody can really hear anything else. Fortunately, there is an excellent article by Christopher Martin that digs  deep into this argument and shows why it isn't anything like the argument from design.

I will go through this article slowly; very slowly. Just a paragraph or two at a time. It is long, and sometimes technical. The article can be found here.

The Fifth Way, as often remarked, depends on final causality, explanation in terms of an end, of what is the point of things. The aim is to show that the world, like its parts, requires an explanation in terms of what it’s for, and what the world is for is set by God. It is a mistake to say that this argument is based on the world’s being for a purpose: it is rather based on the world’s having a point, which is at first sight quite another thing. The circulation of my blood has a point, but it does not have a purpose: nor do even I have a purpose in circulating my blood, since circulating my blood is not something in the strict sense which I do. I can’t help it. It is true that in order to reach God Aquinas has to argue that the point of the world has to be a purpose set for it by God, but that is a further step in the argument.

So explanation in terms of an "end" is different from explanation in terms of a "purpose." Martin's circulatory system has an explanation in terms of an "end", of "what it's for": to deliver oxygen throughout his body. But it does not have a purpose: it might have been created directly by God, or by blind evolutionary forces. Whether it is a part of something larger that has a purpose or not, considered as a part of the system of his body, Martin's circulatory system only has an end, not a purpose.

This is the briefest of all the Five Ways, and its structure is apparently clear.

1. We see that there are things that have no knowledge, like physical bodies, but which act for the sake of an end.

2. But things which have no knowledge do not have a tendency to an end unless they are directed by something that does have knowledge and understanding.

3. Therefore there is some being with understanding which directs all things to their end, and this, we say, is God.

This is his formalization of the Fifth Way.

But this simplicity is deceptive, and the history of natural theology and apologetics has made it yet more difficult for us to read this argument as we should. Most people would want nowadays to object to the first premiss, and to deny that we see that physical bodies act for the sake of an end. But they would grant that if we saw physical bodies acting for the sake of an end, we should conclude immediately to the existence of God. Aquinas does not agree, I think. He thinks that it is almost unquestionable that e.g. physical bodies act for the sake of an end: what is tricky is the step from the unconscious end-directedness which we see all around us to the conscious end-directedness which he needs to assert if he is to prove the existence of God. 

An important point. One of the key differences between Intelligent Design and the Fifth Way is that in the former, ends and goals are difficult to find but if they are, the existence of a Designer is immediately inferred. However, in Aquinas, it is obvious that physical systems act for the sake of an end; the harder part is getting from that fact to the existence of a Designer. This will become clearer as the article proceeds.

That's enough! I told you this would be short! Snippets. The blog is supposed to be digestible.

The take home points:

• There is a difference between "end" and "purpose"; as Martin will make clear later, something can have an "end" relative to the system of which it is a part, even if that system does not have any overarching purpose.
• In the Fifth Way, the existence of "ends" in the world is easy to find; it is the move from this fact to the existence of God that is difficult.

The Teleological Argument from St Thomas Aquinas - The Fifth Way

Consider a can of flammable liquid. It has a "flammable" label on it because it has a disposition to catch fire or explode, in a way it doesn't have a disposition to freeze or turn into an oak tree. Even if it never catches fire, it still always has that disposition, and thus, in a sense, "points" to the production of fire over ice or oak trees.

Does that sound plausible to you? If so, then you may be skirting dangerously close to final causes/teleology and an argument for the existence of God called the "teleological argument", also known as "Aquinas's Fifth Way."

Let's take a look:

The fifth way is taken from the governance of the world. We see that things which lack intelligence, such as natural bodies, act for an end, and this is evident from their acting always, or nearly always, in the same way, so as to obtain the best result. 

In other words: causal dispositions. Flammable liquid lacks intelligence, but has a disposition to act for the final effect of "flame" and not for the final effect of "ice" or "oak trees".

Now whatever lacks intelligence cannot move towards an end, unless it be directed by some being endowed with knowledge and intelligence; as the arrow is shot to its mark by the archer.  

In other words, how does the flammable liquid "know" to act for the final effect of flame rather than ice? We can explain why a person acts for a particular end, because they are intelligent. We can explain how non-intelligent building materials such as concrete and steel act for the final effect of becoming a building because it is directed to that final effect by intelligent beings.

So how can a non-intelligent natural substance act for a specific final effect, since it isn't intelligent? Obviously, because it is being directed by an intelligence, in the same way the builder directs the concrete and steel to become a building.

Therefore some intelligent being exists by whom all natural things are directed to their end; and this being we call God.

In other words, the very existence of causal dispositions shows that there is an intelligence behind the workings of the universe. We could put this argument into a syllogism:

1. Final causes, in order to be efficacious, must exist (duh)
2. If they exist, they must exist either in A) reality, or B) a mind, or C) a Platonic "third realm" (where else?)
3. They do not exist in reality (because they have not happened yet; the flammable liquid has not yet caught fire yet)
4. They do not exist in a Platonic "third realm" (assuming Platonism is false)
5. Therefore, they must exist in a mind

But clearly, no human mind directs flammable liquids to their final effect of flame, so it must be whatever is responsible for the very existence of flammable liquids.

Now consider further that a "disposition" is a potential to act a certain way, but for that disposition to become real, some other state of affairs must "bring it out". E.g., a match must be dropped into the flammable liquid in order to make its potential to be on fire into an actuality, And thus, you also have the beginning of the First Way...