Her name is Amanda. She is a wonderful character, with great moral values. She and I always enjoyed talking at the dinner table in college; we'd laugh about whatever was going on around us, we were both forensic science majors (before I switched majors); both of us were taking biology, and she usually has a great deal of common sense. Despite our friendship, we always differed on just about every debatable topic. She is pro-life; I am pro-choice. She was for capital punishment; I am vehemently opposed to it. She puts an inordinate amount of faith in the Bible; I view it as a trivial work of fiction. Needless to say, she believes in Creationism; I believe that we are products of evolution.
We always got into arguments at the dinner table. We remained friends, but we always got into arguments. The one thing that I could never get over was that she was a forensic science major and rejected any piece of science that conflicted with the old testament. She always tells me that "Evolution is only a Theory;" this is what kills me.
"Evolution is only a theory." Many fundamentalists chant that mantra when they want to protect their views. I find myself fuming on the inside when I hear this. You can believe in your religion and accept evolution simultaneously; they often do not conflict, but no scientifically literate individual would willingly state the above mantra.
Most of us, when we hear the word theory, think of a proposed idea with insufficient knowledge to be considered valid. Dictionary.com defines a theory as:
Theory - a coherent group of tested general propositions, commonly regarded as correct, that can
be used as principles of explanation and prediction for a class of phenomena:
A theory is actually a very high degree of confidence. The reason why evolution is a theory and not a law is that there is no way to experimentally prove this. Evolution takes too much time and depends on variables that cannot be independently manipulated. Imagine trying to design an experiment to prove evolution; you can't! This is why evolution is "only" a theory; the quotation marks parody the fact that all scientific theories are very well established.
This is in contrast to a law, which is an idea that has been thoroughly tested and found to have stood strong despite several attempts to "foil" such principle. Scientists are really designing experiments in an effort to disprove their hypothesis. This is why a law is the most powerful degree of certainty in science.
So, where do we have absolute truth in science? We don't. Well, sort of. We could state that it is absolutely true that 3 is a prime number, or that adding 2 jelly beans to 3 jelly beans yields 5 jelly beans, but these are rules of mathematics, which is really science without the tangible world. Once you add the physical universe, you can no longer state that you are "absolutely certain" about something; this concept doesn't exist.
Gravity, currently a law, was once a theory. It remained a theory until Henry Cavendish created a device that could determine the universal Gravitational constant, G, which equals 6.67 x 10^-11 Nm^2/kg^2. It is possible that one day, gravity will be replaced by an even better explanation. Nobody currently knows why gravity exists; we only know how it exists.
On the scale of scientific certainty, the most basic level is a paradigm. A paradigm is a proposed, highly uncertain model, or explanation of how something works. Aristotle's explanation of how the universe worked was a paradigm; it had no real proof, other than a few inert, incomplete observations about how things always "seek rest." He was absolutely wrong on that matter.
After a paradigm is a hypothesis, which is an announced, educated proposal. Some call it an educated guess, but a hypothesis is better than this. Evolution does not contain a real "hypothesis" because it cannot be tested. A theory occurs when instead of directly testing a hypothesis, people make observations related to the idea, all of which seem to support it. Not all scientists have to definitively agree on a theory; but most should.
Where does creationism or intelligent design fit on this spectrum? Think for yourself on this one. I don't think there will ever be true scientific support for creationism, since evolution can consistently explain what creationism cannot. Evolution does not ever have to become a law; a theory remains valid until a better explanation is reached; the only way to "kill" an idea is with a better idea.
My conclusion: Evolution may only be a theory, but on the same scale, creationism is not even that. I am not telling people to drop their religion; I have many Jewish and Christian friends who accept evolution over creationism, so there is no reason why you cannot have your cake and eat it, too.