Theory vs. Fact: The Erroneous Premise

A common representation by many religious people who are skeptical of the theory of evolution is that it is "just a theory" and not "fact." Making this statement reveals an underlying misconception of just what a theory is. In the realm of science, "the meaning of theory is very rigorous: a theory must be based on observable facts and must make testable predictions." (Wikipedia: Evolution As Theory and Fact)

In some respects, theories are on a higher order than simple facts because theories serve to explain facts. Very often the word "fact" is used to convey something that is presumed to be immutable or unalterably true. This is not the case in a scientific sense. Something is factual when its predictions have survived so many tests that continuing to perform tests makes little or no sense; its degree of probability is extremely high. In this context, the consensus among scientists is that evolution is indeed a fact as well.

It's quite possible that what many skeptics intend to say is that evolution is a hypothesis, i.e., a proposition set forth as a possible explanation for certain phenomena. The problem here is that it has been a hundred and fifty years since evolution has been considered a hypothesis. It has long since graduated to accepted theory. Bearing in mind that theories are never proven absolutely true, current or accepted theories - to be more precise - have survived numerous tests to invalidate them, thereby rendering their probability very high.

At this point, we arrive at the reason something like intelligent design is unacceptable as a scientific theory: its predictions are not testable! Rational scientists do not preclude the possibility that there may be an intelligent designer behind the creation of the universe; they merely contend that such a hypothesis is untestable, ergo not fit for presentation in the scientific classroom. To be more precise, predictions made by intelligent design are not based on observable facts. They often purport to be, but so far these claims of fact have been scientifically refuted. The essence of ID is that where there is no explanation for something as of yet, e.g., gaps in the fossil record, the default explanation is there must be an intelligent designer.

In short, ID proponents thought that if they presented intelligent design as a scientific theory, it would be suitable for the science classroom. As jurisdictions throughout the country are beginning to confirm, whatever ID is, it is not science. "...[I]t is unconstitutional to teach ID as an alternative to evolution in a public school science classroom." (The TalkOrigins Archive: Kitzmiller v. Dover Area School District)