Intelligent Design (ID) is simply Creationism with the Biblical references stripped away. ID promoters say they can infer the existence of a Designer from the "Irreducible Complexity" and the "Complex Specified Information" in living things, but those concepts actually leave a LOT of things unanswered, such as.....
- Why would an IDer make the eyes of all vertebrates wired backwards with the nerve fibers exposed and a blind spot, while the eyes of cephalopods are wired forwards, with the visual receptors facing the light and no blind spot?
- Why would the IDer make any animals lay eggs, making the offspring and often the parents vulnerable to predators or rivals instead of bearing live young?
- Why would an IDer make whales that must breath air to survive, but at the same time they cannot survive on land?
- Why would the IDer make the wings of bats, birds, and pterosaurs different from each other, instead of giving them all the same ideal design?
- Why would an IDer allow entire groups of animals to become extinct?
Natural selection (Nat Sel) can account for all these things, because it is a blind process that never takes future events into account, and must rely on the structures organisms already have to modify them into new forms. Nat Sel could not simply give birds and other flying vertebrates two extra limbs to enable them to fly, so it merely modified the forelimbs. The modifications differed in the three types of flying vertebrates because of the random element involved in Nat Sel. Nat Sel made whales without gills and also without legs because whales didn't need either to survive and reproduce, even though having them would have made them survive either being cut off from air or being stranded on a beach. If either of these happen to a few of them, the rest will continue to survive and perpetuate the species. Nat Sel made vertebrate eyes with bad wiring because it worked better than no eyes at all. Nat Sel made most animals lay eggs because they could still reproduce (by greatly overproducing). Nat Sel has no interest in ideal designs, only in what happens to work a little better than the designs that came before, regardless of what those designs turn out to be. And Nat Sel could never simply recreate from scratch any species that becomes extinct, which is why mammals replaced the dinosaurs and the dinosaurs themselves may never return. Surely an IDer would have simply created mammals immediately and not bothered with dinosaurs at all.
Ironically, if those Creationists and ID promoters had their way and their teachings were allowed in science classrooms, then critiques of their claims and arguments would also have to be allowed in....and that would actually destroy the credibility of Creationism and Intelligent Design once the totally unscientific and dishonest nature of those dogmas became clear.
Intelligent Design theory may be bad science, but it is good politics. People with no grounding in the scientific method and philosophy are highly susceptible to its arguments, for the simple reason that the scientific method does not come naturally to people. After all, if the scientific method did come naturally to people, it wouldn't have taken humanity more than three thousand years after the discovery of iron to figure out that you can make a boat out of it.
So what is the basic philosophy of Intelligent Design, and how does it differ from the philosophy of science? Well let's review: the Intelligent Design argument goes like this:
"Evolutionists cannot explain exactly how [insert species or organ name here] evolved."
"Therefore, evolution theory cannot explain how it evolved."
"Therefore, it could not have evolved."
"Therefore, it must have been magically created by God ... er, an "intelligent designer"."
Each of these steps is riddled with falsehoods and basic logic errors. Let us address them one at a time, before we discuss the fundamental reason why Intelligent Design is completely useless.
Step 1: "Evolutionists cannot explain exactly how [insert species or organ name here] evolved". In a surprisingly large number of cases, this statement is actually false. In many cases (such as the Bombardier beetle), the feature is described inaccurately, in order to exaggerate the unlikelihood of it evolving naturally. In other cases, it is claimed that there is no scientific explanation when in fact there is. But nevertheless, with millions of species in the world, it is obvious that scientists could not possibly have developed a complete family tree for every single one. The real question is: why is this a problem? It may seem like a problem to you, but it is actually not, as we shall see.
Step 2: "Therefore, evolution theory cannot explain how it evolved." If you pick a name of a species and an organ from that species out of a hat and I can't fill in its family history, then I lose, right? Well that's not really how it works. Contrary to what you might think, there is a difference between explaining how things work (ie- science) and giving a complete history. As an analogy, imagine that you see me get into a car in Toronto on Friday morning and you hear that I arrived at my destination in Philadelphia late Friday evening. You would naturally conclude that I drove my car to Philadelphia. If you could not say exactly which route I followed, would that shake your confidence in this theory? Of course not.
You don't know whether I crossed the border at Niagara Falls or Buffalo. There is a "missing link", yet that does not disturb you at all, does it? The correct way to disprove this theory is not to point to the "missing link", but to show that the theory makes predictions which are different from the outcome. For example, the theory predicts that it would take at least 10 hours. If I arrived in Philadelphia one hour after leaving Toronto, the theory clearly makes a prediction which is much different from reality, hence the theory fails. Perhaps I took a flight and then rented a car which just happens to be the same make, model, and year as my car. But the fact that a theory can't give you a complete history does not mean it fails; you need to generate a prediction with that theory and then show that this prediction is different from reality.
Step 3: "Therefore, it could not have evolved." To return to our previous analogy, this is like saying that I could not have driven from Toronto to Philadelphia if you cannot explain which route I took. Let's be very clear about this: neither science, religion, or any other intellectual method will ever produce a reliable complete history of all the species on this planet. Too much evidence has been obliterated over the eons. There will always be unanswered questions. But these are not "holes in the theory"; they are holes in our history.
The distinction between theory and history is a crucial distinction which "intelligent design" proponents invariably ignore in their zeal to attack evolution. The scientific theory of evolution only provides a mechanism which successfully predicts many otherwise staggeringly unlikely patterns in nature and in the fossil record. It does not provide a complete history of our entire biosystem, nor should it be expected to. It would be thoroughly illogical to conclude that a mechanism must not work if you can't use it to fill in a complete history. It works if its predictions are not contradicted by observation and it is found to be necessary, ie- it explain patterns that would otherwise beg for an explanation, such as the coincidental patterns of species characteristics and migration paths, or the fact that features never abruptly jump from one animal family to another. Evolution meets and passes these tests with flying colours, which is why "intelligent design" proponents try to move the goalposts. That is why they unreasonably demand that it fill in a complete history of our world before it can be considered a successful theory.
Step 4: "Therefore, it must have been magically created by God ... er, an "intelligent designer." Now it goes without saying that this is primitive logic: this is the exact same flawed logic used by the ancient Greeks to conclude that since they didn't understand lightning, it must have been thrown down from Mount Olympus by Zeus. The reasoning here is that if you can't explain the mechanism for something, then any story about it must be correct. And keep in mind: once again we encounter the distinction between a mechanism and a story, ie- a scientific theory and a history.
Of course, an "intelligent design" proponent would argue at this point that "intelligent design" actually fulfills my earlier tests for a scientific theory. After all, it can predict any kind of species, so its predictions are never contradicted by observation1. And since evolution theory can't generate a complete history, "intelligent design" is necessary! However, this argument has three crucial flaws. As stated previously, it is not necessary for a scientific theory to function as a complete history, and in fact, expecting it to do so is totally unreasonable. Also, the theory is generally defined in such a manner that it denies evolution, so the patterns which were explained by evolution would require explaining once again. But the argument also has a third huge flaw. Can you see it?
Here's a hint: "intelligent design" can predict any kind of species, no matter what it looks like. This is touted as the great strength of "intelligent design" theory, but it actually proves that "intelligent design" is completely useless. You see, if you make a real prediction, you are not just predicting what will happen: you are also predicting what will not happen. If I use the theory of action/reaction to predict that a rocket will move forward in space when the engine is fired, I am not just predicting that the rocket will move forward: I am predicting that it will not move backwards or stay still. Similarly, the mathematical equation 2+2=4 does not just say that 2+2=4; it also says that 2+2 does not equal 3, or 5, or 100.Predictions and the Failure of Intelligent Design
That is what it means to make real predictions; if a "theory" predicts that anything can happen, it is not a scientific theory at all. Imagine if someone promoted a theory of rocketry by saying that no matter whether the rocket goes forward, backward, or nowhere, his theory will predict it. You would be quite justified in asking what on Earth his theory is good for, right?
When you think about it, a theory which can predict anything is actually a theory which predicts nothing. An open-ended "prediction" which is incapable of ever saying "no, we won't see that" is absolutely, utterly, completely useless. And that, ladies and gentlemen, is "intelligent design" theory in a nutshell: completely useless.