Saturday, November 14, 2009

Final Causes in Nature

This is the final paper I wrote for my philosophy class last semester.

According to Empedocles, the universe is at times dominated by Love, and at other times by Strife. During times of Strife, things are spread apart, and the world ends up scattered. But in times of Love, things become attracted to one another, and the world reforms into a sphere. During this time, living things are generated randomly. Limbs and organs will attach and form a whole, creating all forms of living things, including monsters. “Many neckless heads sprang up. Naked arms wandered, devoid of shoulders, and eyes strayed alone, begging for foreheads.” (B 57.1-3) When a living thing happened to be organized in an appropriate and working way, they survived, and reproduced. When a living thing was disfigured and ill-formed, they were not able to survive.

This concept seems oddly prescient, and similar to the modern theory of evolution, which has a preponderance of evidence in its favor. Due to this, one could call this Empedocles' theory of evolution, though this is something of a misnomer, since evolution implies gradual change over time.

Aristotle objects to Empedocles' theory of evolution, because he claims that if it were true, there would be no final causes in nature. According to Aristotle, there are final causes in nature, therefore Empedocles' theory of evolution cannot be true.

I would say that Aristotle is wrong. Nature does not exhibit final causation. Nature merely seems to exhibit final causation; it cannot actually have final causation, because final causes require intentionality.

First, I will define some terms. The final cause is that for the sake of which something is done. If X is the final cause of Y, then Y is done for the sake of X. This is the same as Aristotle's definition.

An event is spontaneous, if it did not have a final cause. Aristotle gives two more qualifications of spontaneous: That it might have come about for the sake of something, and that it had an external cause.

The first is unnecessary. Anything might have come about for the sake of something. A rock could have fallen into a position to give a person an elevated surface to sit or climb on. A glacier may have gouged lakes into the land to give cities clean water. Because any event can (efficiently) cause other events to occur, any event can be ascribed a hypothetical final cause.

That a spontaneous event have an external cause seems to later be contradicted by Aristotle. He gives an example of a horse that saved itself spontaneously, because it did not leave the barn for the sake of safety. But the horse's leaving did not have an external cause. The horse moved itself. In either case, this particular requirement does not seem to be relevant, so it will be ignored.

Using these definitions, Aristotle's assertion that an event either has a final cause, or it is spontaneous. By the definition of spontaneous, if an event does not have a final cause, it is spontaneous. If an event is not spontaneous, it has a final cause.

However, using this definition of spontaneous, it is not clear just what is spontaneous, and what has a final purpose. Perhaps Empedocles' theory of evolution could generate living things with a final purpose, rather than spontaneously. It is important to determine what constitutes having a final cause, and what doesn't.

I propose that intentionality is required for a final cause. I would say it follows from the language of the definition: If Y is done for the sake of X, then Y is done with the intention that X follow. If X follows Y unintentionally, Y did not happen for the sake of X. I find it hard to see how it could be any other way.

Nature in general does not have intentionality. Natural forces, such as weather and fire, and plants do not have intentionality. Some animals may have a degree of intentionality. Because nature does not have intention, natural occurrences cannot have final causes, except perhaps some particular animal actions.

This concept can seem counter-intuitive. Particularly because nature seems so well-ordered. However, order does not require intention to come about. For example, a crystal forms in well-ordered grids, due to the nature of the material, and chemical laws. The molecules and atoms do not intend to form a crystalline structure. The order does not come from final causes, but from efficient causes.

This is analogous to living things. As Aristotle says, teeth grow in the same order in all humans, incisors and canine at the front, and molars at the back. This is analogous to the way that the crystal forms the same repeating pattern. Again, the teeth do not grow in the same way consistently because of a final cause. It is because of an efficient cause, the biology of humans.

Efficient causes can give the appearance of final cause. If Y is the efficient cause of X, it is easy to conclude that X is the final cause of Y, since it is frequently the case. But it is clearly not always true. For example, in the case of the rain and the corn. The rain falling is the efficient cause of the corn growing, but the corn growing is not the final cause of the rain falling.

Aristotle makes several arguments that nature exhibits final causation. The first is as above, that teeth and other natural occurrences normally come about in a certain way. According to him, this cannot come about due to spontaneity. To back this up, he appeals to common usage and says that heat in the summer, and rain in the winter are not attributed to spontaneity. (198b33-199a8)

I respond to this by saying that there is no reason that an event that happens regularly or normally can't be spontaneous. That property does not follow from the definition, and in fact, I would say that regular spontaneity is actually fairly commonplace. For example, the aforementioned crystal, or corn growing after rain. That heat in the summer and rain in the winter are not commonly referred to as spontaneous only shows that our technical definition does not exactly match the everyday use.

This may warrant attention, and a redefinition of the technical term. I don't think it's a grave concern though, as this definition seems appropriate in circumstances where the common term is used, if not where it is not used. Though, if another definition is chosen, this entire subject deserves to be critically re-evaluated, since I rely heavily on that spontaneity and final causation are mutually exclusive. A new definition may not necessarily have that property.
Another argument is that a builder building a house is analogous to a swallow building a nest. The building of the house has a final cause, for people to live in the house. Similarly, it does appear that the building of the nest has a final cause, for swallows to live in the nest. He extends the analogy to ants building ant-hills and trees growing leaves.

However, Aristotle's own argument can be used against him. In the same way that a builder is analogous to a tree growing leaves, a gardener watering flowers is analogous to rain watering crops. If a gardener watering flowers has a final cause, then rain watering crops also has a final cause. The gardener does have a final cause, therefore the rain has a final cause. But this contradicts Aristotle's conclusion that rain does not have a final cause.

This takes the same form as Aristotle's original argument, so if it is valid, this argument is too, and if this argument is invalid, the original argument is invalid. The second argument contradicts what was previously determined, so it cannot be valid. Therefore, the original argument is not valid either.

Aristotle's next argument pertains to mistakes. He claims that if a mistake is made, it is because a purpose was attempted but failed to be achieved. He continues that there are mistakes in nature, such as when an animal is born with birth defects. Therefore, there is a purpose in nature.

Aristotle's does not support his first claim that mistakes imply purpose. But this seems to serve well as a definition. A mistake is when a purpose was attempted, but failed. From this definition, it can be deduced that when a mistake occurs, it had a final cause, and it was in vain.

But determining a purpose based off of a mistake is difficult if not impossible. For example, consider the famous movie, Star Wars. In that movie, Han Solo brags about how fast his ship is and states, “It's the ship that made the Kessel Run in less than twelve parsecs.” The parsec is a unit of distance, not time, so Han Solo must have misspoken. But is this a mistake on George Lucas's part? Without knowing any more information than that, it is not possible to determine whether George Lucas mistakenly used the wrong term, or if using the term incorrectly was his intention, perhaps to characterize Han Solo as somewhat uneducated.

In order to determine whether a particular action was a mistake or not, the purpose must be known beforehand. Attempting to go the other way around, by determining purpose from a mistake is dubious at best.

Going back to nature, it is unclear what a mistake is. An animal born with a birth defect does seem at first to be a mistake. Certainly it is unusual and not what typically happens. But that alone is not enough to decide if it is a mistake or not. Consider the paintings of Leonardo da Vinci, Michelangelo and Picasso. Leonardo's and Michelangelo's paintings are very realistic, while Picasso's paintings are not at all. This does not, however mean that Picasso's paintings were mistakes. Also, consider the crystal again. Occasionally, the process that makes the repeated pattern is interrupted, or in some way disrupted. Then, slight irregularities are introduced into the crystal. These irregularities are no more mistakes, than the regular pattern is intentional.

A possible objection that someone could make against the idea that final causation requires intention, that Aristotle did not make, is that machines can be said to have final causes. This is very common. A toaster heats up for the sake of toasting bread. A garage door opener spins its motor for the sake of opening the garage door. These machines do not have intentionality, but they do have final cause.

My response to this is that it is not the intentionality of the machine that goes toward the final cause, but the intentionality of the human that either made the machine or used the machine. In this way, the machine itself does not need intention to have a final cause.In this way, nature could be considered to have a final cause if there is some kind of creator god with intentionality to give it one.

This particular aspect is outside the scope of this paper. Suffice to say, nature, on its own, has no final cause.

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