"Just a theory"

After seeing more references than I care to remember about evolution merely being a "theory," I got annoyed and wrote up a post on my G+ account.  Decided to share it here.  Full text follows:



Particularly whenever somebody mentions evolution, or speaks against creationism, one of the evolution deniers will inevitably throw out the phrase “just a theory.”

I won't go so far as to say that it enrages me, but it does piss me off.  As Inigo Montoya says in The Princess Bride, “You keep using that word.  I do not think it means what you think it means.”
Words used in different contexts can mean completely different things.  To most of the English-speaking world, in common parlance, “theory” refers to how something is thought to work.  It's how something works on paper, but hasn't necessarily been conclusively proven in practise.  It may or may not be commonly believed, but in the end, it is unproven.

In science, it has quite a different use.  It is not some airy-fairy thought that scientists have faith in.  It is not merely something that they haven't managed to disprove yet.  It is not a hypothesis.  Steven D. Schafersman* describes it better and more forcibly than I'd be able to without borrowing from him:


"The final step of the scientific method is to construct, support, or cast doubt on a scientific theory. A theory in science is not a guess, speculation, or suggestion, which is the popular definition of the word "theory." A scientific theory is a unifying and self-consistent explanation of fundamental natural processes or phenomena that is totally constructed of corroborated hypotheses. A theory, therefore, is built of reliable knowledge--built of scientific facts--and its purpose is to explain major natural processes or phenomena. Scientific theories explain nature by unifying many once-unrelated facts or corroborated hypotheses; they are the strongest and most truthful explanations of how the universe, nature, and life came to be, how they work, what they are made of, and what will become of them. Since humans are living organisms and are part of the universe, science explains all of these things about ourselves.

"These scientific theories--such as the theories of relativity, quantum mechanics, thermodynamics, evolution, genetics, plate tectonics, and big bang cosmology--are the most reliable, most rigorous, and most comprehensive form of knowledge that humans possess. Thus, it is important for every educated person to understand where scientific knowledge comes from, and how to emulate this method of gaining knowledge. Scientific knowledge comes from the practice of scientific thinking--using the scientific method--and this mode of discovering and validating knowledge can be duplicated and achieved by anyone who practices critical thinking."


Just a theory?  Scientific theories contain some of the best of humanity and what we're capable of.

Just a theory?  To those using that phrase about evolution for example - excuse the rudeness - but please shut up and go away.  You don't understand the words you are using, and it is pointless to engage with you, as you don't know the language, and don't want to know the language.


* http://www.geo.sunysb.edu/esp/files/scientific-method.html
Bolding in the excerpt is added by me.