It is one of the great enigmas of our time that the same people who utterly depend on the products of modern science for their health, leisure, even life, can be so naïve and obtuse when it comes to one scientific theory that is the cornerstone of biology: evolution.
Anyone who understands what a scientific theory is will also understand that intelligent design, aka creationism, is not one.
Evolution is a scientific theory. It should be taught as such. And in most schools it is. The misinformation seems to be in determining exactly what a scientific theory is and how it differs from a scientific law or hypothesis, or a religion.
A scientific law is like the law of gravity or Newton’s laws of motion. They are simple, direct, truthful statements that define a very specific observation. Laws are simply statements that everyone agrees to be true, so that they can move on.
Hypotheses are deductions based on observations and what is known to be true at the time. They are educated guesses, not haphazard or wild guesses.
A theory is an explanation of a set of related observations or events based upon proven hypotheses and verified multiple times by detached groups of researchers. One scientist cannot create a theory; he can only create a hypothesis.
In general, both a scientific theory and a scientific law are accepted to be true by the scientific community as a whole. Both are used to make predictions of events. Both are used to advance technology.
The biggest difference between a law and a theory is that a theory is much more complex and dynamic. A law governs a single action, whereas a theory explains a whole series of related phenomena.
Compare a slingshot to an automobile. A scientific law is analogous to a slingshot. A slingshot has but one moving part - the rubber band. If you put a rock in it and draw it back, the rock will fly out at a predictable speed, depending upon the distance the band is drawn back.
An automobile, on the other hand, has many moving parts, all working in unison to perform the chore of transporting someone from one point to another point. An automobile is a complex piece of machinery. Sometimes, improvements are made to one or more component parts. But the function of the automobile as a whole remains unchanged.
A theory is like the automobile. Components of it can be changed or improved upon without changing the overall truth of the theory as a whole.
Some scientific theories include the theory of evolution, the theory of relativity and the quantum theory. All of these theories are well-documented and proved beyond reasonable doubt. Yet scientists continue to tinker with the component hypotheses of each theory in an attempt to make them more elegant and concise, or to make them more all-encompassing. Theories can be tweaked, but they are seldom, if ever, entirely replaced.
Most importantly, scientific theories are a part of how science works. You start with a question to which you do not know the answer. You observe, collect data, perform experiments and then come up with a hypothesis to explain it. Other scientists take your hypothesis and verify it with observations of their own.
Over time, it develops into a theory, which nearly all scientists can then use to predict what will happen next. Or if the facts do not support the hypothesis, it is abandoned, even if the hypothesis was an elegant one. Thomas Huxley once wrote, "The great tragedy of Science is the slaying of a beautiful hypothesis by an ugly fact."
Creationism is not a theory, nor even a hypothesis, because it was not arrived at by the scientific method. Creationism starts out with the answer - that God created everything. Then it works backward to try to find pieces of "evidence" to support the conclusion that has already been made. It is the opposite of science.
If schools want to teach a class in creationism, they must call it what it really is: religion, not science. And it’s not just any religion. Catholics and many Protestant denominations, such as Disciples of Christ, Lutherans, and most Methodists have no problem accepting the scientific truth of evolution. Creationism is part of the conservative, fundamentalist religions. But they are the ones who scream the loudest for their reactionary causes.
And if it is taught in schools, it should be labeled as such. Then let the schools who teach it be exposed to the consequences of intermingling church and state, for that is exactly what they would be doing.