Tuesday, June 16, 2009

A Proof for the Existence of God

If one reads Question 2, Article 3 of St. Thomas Aquinas's Summa Theologiae, he will find five ways to prove from natural reason alone that God exists. The juniors (my class) read these texts in our theology class this last year, and one of our paper topic options for that class was to go through and explain in detail one of the five ways and the arguments on which it is based. This was the topic I chose, and I wrote on the fifth way - an argument from the governance of nature. Here is my paper.

In his Summa Theologiae, St. Thomas claims that the existence of God can be proven in five ways. The fifth of these ways is based in large part on Aristotle’s Physics, and concerns the governance of things. Aristotle says that natural bodies lacking knowledge are seen to act always or for the most part in one particular way, and concludes from thence that they are acting toward their end, or what is best for them. Taking up his definition of chance, one sees that this sort of action cannot be attributed to chance. St. Thomas then proceeds further with this argument, saying that the action must therefore be due to intention, which, however, these natural bodies lack, since they are without knowledge. At this point, one can only conclude that such bodies are guided by an external intelligence, by “someone who knows and understands,” and this someone we call God.
In order to convince himself of this argument, one must first examine natural bodies lacking knowledge so that he might see that they always or for the most part act in the same way. A good example of such a body is an insect. In looking at bees, one sees that they inevitably build six-sided honeycombs. All bees, everywhere in the world, do this. Another example of a non-rational natural body is a tree. Trees also have this kind of action in them; every year they produce fruit of some kind which eventually ripens and falls to the ground. This production of fruit is also always and everywhere the case. Many other examples could also be given to illustrate this point.
A further consideration will show that this action in such bodies attains some kind of end which is good for them. In the example of the bees, six-sided figures are the strongest by nature. Thus, the bees’ honeycombs will be sure to be sturdy and last a long time, providing them with shelter. Clearly in this case a good end is attained by the action of the bees. In the case of trees, the fruit produced contains seeds which, when the fruit falls to the ground and rots, can germinate and grow into new trees. Thus in this case, the production of fruit attains to the preservation of the species, which is also a good end.
An additional reason for believing that the action of nature is for an end comes from a consideration of human art. Art tries to imitate and in some cases improve upon nature, always with an end in mind. In agriculture, for example, human art tries to improve upon natural conditions and facilitate the natural process of plants growing and producing their fruit. This illustrates that there is an end which such natural action should obtain, and which man is trying to help it obtain through the art of agriculture. If there were no good end to be achieved through these natural processes, it would not make sense for agriculture to exist and try to facilitate and improve them. Clearly, then, such action in nature produces a good end, since men try to imitate it.
The next question to be considered is from what cause such action in these natural bodies is produced. One possibility is that it is caused by chance. The definition of chance as given by Aristotle in the Physics is as follows: “In things which come to be for the sake of something simply, when things whose cause is outside come to be not for the sake of what happens, then we say [they come to be] by chance.”[1] In other words, when several events which have their own proper causes and ends (“things which come to be for the sake of something simply”) happen to come together, producing some other end separate from those proper ends and not aimed at by any of the individual events (“things whose cause is outside come to be not for the sake of what happens”), the result of this coming together is said to be by chance. For example, if a mother bird leaves her nest to find food for her young, and while she is gone an eagle comes and eats the baby birds in the nest, we would say that the mother was saved by chance. Her leaving the nest with the end of getting food for her young happened to come together with the eagle’s raiding of the nest with the end of finding dinner for himself, with the result that she was saved from being eaten. This result was the proper end neither of the eagle’s action nor of the mother bird’s, yet nevertheless it came about because of the coincidence of those two events. Such a result, Aristotle says, is caused by chance.
Another property of chance is that it is the cause of things which do not happen always or for the most part. In speaking of luck, Aristotle says, “First, then, since we see that some things always come to be in the same way, but some do so for the most part, it is apparent that luck is called the cause of neither of these; nor are these by luck, either what is by necessity and always, or what is for the most part.”[2] Aristotle later goes on to say that luck and chance differ only in that luck comes about in things which have choice, while chance comes about in things without choice. “And because of this fact neither the unsouled nor a beast nor a child does anything by luck, because they do not have choice…but chance is in the other animals and in many unsouled things.”[3] Therefore, since this is the only respect in which chance and luck differ, neither would chance be said to be the cause of things which happen always or for the most part.
Indeed, this fits very well with the abovementioned definition of chance, as it would be very odd if the same totally disconnected events were to come together always or for the most part. If they did, it would seem as though they were meant to be together that way, and that they were for the sake of the result thus produced by their coincidence. To use the example given, if the mother bird left the nest to find food every time the eagle came and raided the nest, it would seem as though the mother bird was really leaving for the sake of avoiding the eagle and being saved. But this is not what people think, and indeed these two events very rarely coincide. Therefore chance cannot bring about things which happen always or for the most part.
From this explanation of chance it is manifestly clear that it cannot be the cause of those good ends produced by nature’s action. Firstly, as was said, those ends happen always or for the most part, and chance cannot cause such things. Also, it seems evident that the natural action is in fact meant to bring about those ends, from the very facts that the action is so effective in causing them and that the action and the good effect always go together. The tree’s production of fruit always brings about the production of a new tree, and when we see that the seed is contained in the fruit and that the fruit falls to the ground, allowing the seed to germinate, it is clear that the action of producing fruit is meant to bring about the end of producing a new tree. Thus there is no chance coming together of actions having other proper ends, but one action with this very end in mind, and therefore chance by definition cannot be the cause of such action.
Since chance is not causing these actions in nature, there is only one other possibility, and that is that there is intention at work. There is an end, a ‘that for the sake of which’ that all such action is meant to bring about. Aristotle says in the Physics that “there is ‘that for the sake of which’ in things which are and which come to be by nature.”[4] Therefore there must be an intention to bring about this end which ordains that such action take place in order to obtain the end. That there is intention in nature can be seen, once again, by a comparison with art. Art has an end in mind with intention to bring about that end through the actions it does, and since art is an imitation of nature, one must conclude that nature also has an intention to bring about the end. Aristotle addresses this point as well. “And, generally, art carries to an end some things which nature cannot work out, and imitates others. If, then, things which are according to art are for the sake of something, it is clear that things according to nature are too. For the posterior is to the prior in a similar way in what is according to art and in what is according to nature.”[5]
One now runs up against the question of where this intention is to be found. Aristotle alludes to this problem in the Physics. “Whence, some people are at a loss as to whether spiders and ants and such things work by mind or by something else.”[6] It seems pretty clear that since the natural bodies in question are those which lack reason and knowledge, they cannot possibly have the intention within themselves. Bees do not build six-sided honeycombs as a result of having deliberated about which was the strongest structure, nor do trees think about what would be the best way to reproduce. This is merely because these bodies do not have knowledge and reason within themselves. Aristotle affirms this fact. “But this is most apparent in the other animals, which act neither by art, nor by inquiring, nor by deliberating.”[7] One must, however, grant that there is intention at work in the action of these bodies. Therefore, since the intention cannot be within them, it must belong to an external intelligence which orders and directs all things toward their ends. As St. Thomas says, “But things which lack knowledge do not tend toward an end unless they are directed by someone who knows and understands…therefore there is something intelligent, by which all natural things are ordered to an end, and this we call God.”[8] Thus it can be seen that God must exist.
In summary, one can clearly see that nature does many actions always or for the most part, and that these actions always bring about some good end. Chance by definition does not cause action for an end, and thus cannot cause things which happen always or for the most part. As a result, one must say that intention is the cause of this action. Since natural bodies lack reason, they cannot deliberate about an end and the means thereto, and thus they cannot have the intention within themselves. Therefore, there must exist an external intelligence which is guiding nature and its actions so that it obtains good ends, and this intelligent being is what we call God.

[1] Aristotle, Physics, Glen Coughlin translation; book 2, chapter 6, lines 197b18-21
[2] Physics, book 2, chapter 5, lines 196b10-13
[3] Ibid, chapter 6, lines 197b7-8, 14
[4] Physics, book 2, chapter 8, lines 199a7-8
[5] Physics, book 2, chapter 8, lines 199a16-20
[6] Ibid, lines 199a21-23
[7] Ibid, lines 199a20-21
[8] St. Thomas Aquinas, Summa Theologiae, question 2, article 3


Anonymous Curious Philosopher said...

That's a very lucid presentation in general, but there's one thing I'm still confused about.

If I understand correctly, your argument that some non-rational beings act for an end runs as follows:
1) All things which act in a certain way, always or for the most part, act for an end
2) Some non-rational beings act in a certain way, always or for the most part
3) Therefore, some non-rational beings act for an end.

My confusion concerns the major premise of the argument: for example, you say that trees produce fruit always or for the most part; but is it not true that, for the most part, the fruit does not become new trees? Is each fruit not intended to become a tree? If not, how can the intention of the generation of the fruit be the preservation of the species, since this is contrary to the end of the fruit? If so, how does this fit with the fact that, for the most part, the fruit do not become trees? In the latter case, what comes about for the most part would not be intended, and in the former, the end of the tree and the fruit would seem to be contrary.

Perhaps you can enlighten me on this difficulty I have with the argument as it is presented. I would certainly like to know what you think about this.

5:47 AM  
Anonymous Frenchy said...

Even if every individual apple does not turn into a new tree, wouldn't it still be true to say that, in general, the reason that plants drop seed-bearing fruits is so that new plants will grow? That seems fairly obvious (to me, anyway). And in addition I would still also say that the ideal end of each fruit is to become a tree, but this end is frustrated for the most part, probably to prevent there being way too many apple trees. So yes, I'd say that the end of the tree and the fruit is the same, and I would also say that the failure of the fruit to germinate for the most part is ALSO intended, but for a different end - to avoid the rampant overgrowth of the species. So there's sort of a hierarchy of ends going on, and the production of fruit with accompanying failure of most of it to reproduce achieves both of those ends. I hope that makes some sort of sense.

11:02 PM  
Anonymous Curious Philosopher said...

I agree that the reason plants produce fruit is so that new plant will grow, and that the end of each seed is to become a new individual in that species, but your third statement is the difficulty: you say that "this end is frustrated for the most part, probably to prevent there being too many apple trees." To which agent do you ascribe this end? Doesn't the success or failure of growth depend on the conditions of where the seed falls, which is determined by chance? However, it is more likely that a seed will fall in a place where it cannot grow, than a place conducive to its end. If these last two statements are true, then the conclusion is that there are some things which happen for the most part by chance, not by intention; and this is all this is required to disprove the major premise of the argument.

5:41 AM  
Anonymous Frenchy said...

Perhaps each specific location of a seed is determined, as you say, by chance (it's by chance that this seed fell behind the fence as opposed to somewhere else), but since I am saying with Aristotle that chance by definition cannot be the cause of that which happens always or for the most part then I would say that the phenomenon as a whole of most seeds falling in areas not conducive to growth is by intention, not by chance.

11:09 AM  
Anonymous Frenchy said...

Whoops, I forgot to answer your question about the agent. Certainly not the tree, and I would not say chance, either, since it happens always or for the most part. This is where I would reference my essay and say that I see there is intention, but not in the natural bodies themselves, and therefore I will ascribe it to God. :)

11:13 AM  
Anonymous Curious Philosopher said...

So you're saying that the major premise (that which happens always or for the most part is for an end) is per se self-evident, i.e., known by the very definition of the terms?
What do you think about this example: an archer shoots many arrows at a target, yet because of the distance, most of them miss. Certainly every individual arrow is intended to hit; but if this were analogous to the case of the seeds, you would have to say that, as a whole, the arrows were intended to miss. But this seems absurd.
As for your last statement, that "there is intention, but not in the natural bodies themselves", isn't it the very point of the argument that the intention is in the natural bodies, which lacking intelligence, must be moved by an intelligent agent?

9:59 AM  
Anonymous Frenchy said...

This comment has been removed by a blog administrator.

12:27 PM  
Blogger Frenchy said...

Yes, I meant to say that there was intention involved in what was happening with the natural bodies, but that since they lack intelligence, there must be an external agent. Sorry I didn't say that very clearly.

As to the difficulites involving seeds and arrows missing their mark, I'm curious to know what you think about that. I don't want to say that chance causes that which happens always or for the most part, but perhaps there are some kind of distinctions which could be made that would clear things up a bit, maybe between kinds of causality. Your thoughts?

Thanks for your comments, by the way.

12:37 PM  
Anonymous Curious Philosopher said...

I'm not sure what to say about those examples: Aristotle certainly makes it clear that he thinks that anything whatever which happens always or for the most part is intentional. It is clear in most examples of a regular occurrence that this is true. It seems that only when chance is somehow involved that it is unclear.

However, with respect to the argument from intention in nature, I think Aristotle provides at least a way around the difficulty of apparent exceptions to the major premise based on chance; he says (and I think this deserves to be quoted at length): "Luck and chance are causes of effects which, though they might result from intelligence or nature, have in fact been caused by something accidentally. Now since nothing which is accidental is prior to what is per se, it is clear that no accidental cause can be prior to a cause per se. Luck and chance, therefore, are posterior to intelligence and nature. Hence, however true it may be that the heavens are due to chance, it will still be true that intelligence and nature will be prior causes of this universe and of many things in it besides." (Physics, 198a6-12)

What I take Aristotle to be saying here is that if anything comes to be by chance, this presupposes per se causes in nature. But per se causes in nature intend the end, since it does not come to be by chance. But intentionality requires intelligence, etc.

Now Aquinas, when he sets out the fifth way, limits himself to asserting that things which act always or nearly so in the same way act for an end. I think this is different from asserting that anything which happens always or for the most part is intended. By explicitly saying "act" instead of "happens", I believe he is pointing to per se causes, so that a consideration of accidental effects is not needed.

4:51 PM  

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