What is meant by "explanation"

I have often stated that intelligent design fails to explain anything. It offers the explanation that things are the way they are because a designer made it that way, but that does not qualify as an explanation. Here I would like to produce a list of the different meanings we give to the word "explanation".

One meaning of explanation is to provide a causal explanation for something. We can explain malaria by saying that a parasite enters the body by a mosquito bite. The parasite then infects the blood cells and liver cells. The body's response to this infection, and the periodic release of parasites, explains the bouts of fever typical of malaria. This explanation tells us how A causes B (how Plasmodium causes malaria). It also explains things like why malaria is found in some parts of the world, and how to prevent it.

A related meaning of explanation is to break something down into its component parts. We can explain how a car engine works by explaining how the fuel injectors and pistons and transmission and cooling system and other components interact. This might also involve the causal relationships between the parts. Science often breaks larger things into their parts--organisms are described as groups of cells, and cells are broken down into organelles and molecules.

What both of these first two explanations have in common is that it helps us to understand one thing in terms of something else. Another kind of explanation is to explain why something is one way rather than another way. This is something that evolution excels at. Why do we have five fingers rather than four? Why do marsupials dominate in Australia rather than placentals? It is common in other fields as well. Why does the United States have a democracy rather than a monarchy? Why is hydrogen more abundant in the universe than helium?, etc.

At first I was thinking this was a complete list of the ways we use the word explanation. Of these meanings, intelligent design clearly fails to deserve the word explanation. If we want to know the mechanism by which organisms were created, we are out of luck. They just formed. Any attempt to make ID proponents explain how comes up empty. ID does not help us understand organisms in terms of other things as well. And ID most certainly fails to explain why it is this way rather than another. The answer is always the same--because the designer wanted it that way. The designer wanted to use a pentadactyl pattern for a limb, for his inscrutable reasons. The designer wanted to put marsupials in Australia.

But then I realized there is another level of explanation, for designed things. After all, someone might ask why the first iPods were all white, and an answer could be "Steve Jobs wanted it that way". Isn't that similar to the answers ID gives for why things are the way they are? Do we mean something else when we explain designed things?

But "Steve Jobs wanted that way" is not explanation, or at least it is an explanation only in the sense that we can understand his motivations. Is white Jobs favorite color? Did market surveys indicate white would be popular? Jobs is well known as a minimalist, and perhaps the white color and simple lines of the iPod are a result of this personality trait. Or perhaps it was pure whimsy or the flip of a coin. No matter what the reason, we still try to understand Jobs motivation in terms of personality or other motivations. We want to know why Jobs wanted it that way.

Intelligent design fails as an explanation in this way as well, although it need not, in theory. If we could claim to understand the motivation of the designer, then it could be used. Perhaps the designer's goals were maximal effeciency, or beauty, or minimalist lines. Of course, ID offers no such explanations, because there are too many exceptions to any such rules. Life can be inefficient and ugly and complicated. If we make any attempt to claim to know the motivations of the designer, we are accused of wandering into theology. ID proponents make it clear that the designer could want anything for any reason and these reasons are inscrutable to our human minds. ID really could be a science and could be considered an explanation if it offered some insights into the mind of the creator. I suspect it would fail when tested, but at least it could be tested, and at least it could be considered an explanation.

Some forms of creationism actually are explanations. Flood geology actually does attempt to explain the distribution of fossils in terms of causal mechanisms, involving the hydrodynamics of a great flood. It fails miserably at it, but at least it attempts an explanation. Intelligent design is reducing creationism down to the parts that aren't even an explanation. The reason to reject ID is simply because it fails to explain anything, by any definition of the word.

When children ask why the sky is blue, we sometimes say "because God wanted it that way". But that is a cop out. Why didn't God want it red? That is not an explanation. It simply says it's blue because it's blue. If we explain that blue is refracted less than other colors by the atmosphere, then we understand why the sky is blue in terms of other things. This also helps us understand why it is red at sunset, and why the sky of mars is not blue.

I realize this list of the use of the word explanation matches Aristotle's list of the kinds of causes--material, efficient, formal, and teleological. This match gives me confidence that I have a fairly complete list of the ways in which we use the word explanation. However, if there is a way that the word is used that I have not considered, I would appreciate pointing it out.