Thread: "Just a theory"

The purpose of this thread is to serve as a reference for the debunking of the "just a theory" cop out. So far, this mostly relates to people who claim that evolutionary theory shouldn't be taught or is wrong because it is "just a theory" but it certainly can apply to any other science and may be relevant in other discussions. I am tired of repeating this debunking ad nauseum all over the board, so I am putting a thread about it here, as a reference. Please feel free to respond, and start a discussion of this, if there are any questions, additions, or disagreements regarding what I post here.

"Just a theory" - a common cop-out:
In common conversation, the word theory has come to represent when a person has a guess, hunch, inkling, piece of inside information, or some other such half-cocked, yet potentially true idea. This might include, "I have a theory that Jones is boffing his secretary" or "I have a theory that the Cavaliers are going to trade LeBron James to the Lakers." These "theories" are simply speculation that may or may not have any degree of accuracy. They may or may not turn out to be true, and certainly should not be accepted as fact until it happens (ie you catch Jones in the act or see LeBron in purple and yellow).

It would be fair to say, in response to someone proposing these theories, "It's just a theory - we don't know the truth!" These theories should not be taught, accepted as fact, passed off as Gospel truth, or often taken with more than a grain of salt. We are absolutely correct to casually dismiss them with "it's just a theory".

Switching gears, we are absolutely wrong if we accept these definitions or rationale in the realm of science. In scientific language, "theory" does not refer to guesses, hunches, inklings, pieces of inside information, half-cocked or potentially untrue ideas. A "scientific" theory is much different.

Answers.com tells us that a theory is:

A set of statements or principles devised to explain a group of facts or phenomena, especially one that has been repeatedly tested or is widely accepted and can be used to make predictions about natural phenomena.

Furthermore, a terrific explanation of the gap in understanding between vernacular and scientific usage can be found at http://encyclopedia.laborlawtalk.com/scientific

Excerpt (emphasis mine):

Most non-scientists are unaware that what scientists call "theories" are what most people call "facts". The general public uses the word theory to refer to ideas that have no firm proof or support; in contrast, scientists usually use this word to refer only to ideas that have repeatedly withstood test. Thus, when scientists refer to the theories of biological evolution, electromagnetism, and relativity, they are referring to ideas that have survived considerable experimental testing. But there are exceptions, such as string theory, which seems to be a promising model but as yet has no empirical evidence to give it precedence over competing models.

Especially fruitful theories that have withstood the test of time are considered to be "proven" in the scientific sense – that it is true and factual but of course can still be falsified. This includes many theories, such as universally accepted ones such as heliocentric theory and controversial ones such as evolution, which are backed by many observations and experimental data. Theories are always open to revision if new evidence is provided or directly contradicts predictions or other evidence. As scientists do not claim absolute knowledge, even the most basic and fundamental theories may turn out to be incorrect if new data and observations contradict older ones.

As is outlined here, theories are basically the same thing as "established scientific fact". Since they are falsifiable in nature, it is always theoretically possible that contrary evidence could be found. The Earth could theoretically be discovered to be flat and the sun might revolve around it, for example. However, this is practically absurd, as is the case with all established scientific theories.

Going back to our original "theory" examples, if we brought one into the scientific sphere, it might look like this:

Theory: "Jones is boffing his secretary."

Evidence: Every day I hear yelling and panting coming from the office. Every day, they emerge sweaty and naked, holding hands. Some days, I look in and see them on top of one another, moving rhythmically. Recently, the secretary became pregnant and told everyone the baby belonged to Jones. A DNA analysis indicated that the baby was Jones's.

Falsifiability: No one ever actually saw penetration occur. The DNA test could have been wrong (the odds of this are astronomical). All of these indicators might have been wrong - they could have been rehearsing for a play.

Conclusion: While theoretically falsifiable, the evidence in favor of our theory is so overwhelming as to make this theory an accepted fact.


So, as you can see, saying that a scientific theory is "just a theory" is really a gross distortion. Scientific theories don't become theories late one night when a bunch of people are drunk in a lab. Theories become what they are through a long process in which they are constantly being assaulted on all sides by people attempting to falsify and/or reform them. Theories are only accepted if the overwhelming majority of the scientific community subsrcibes to them, and they are insantly vaporized if one tiny iota of evidence to refute them comes to light. If a scientific theory were a baseball team, you could think of it as having a record of 10,000,000,000 - 0. Betting on it to win tomorrow would probably be a safe bet.

Good doctor, I respect your view on this matter - the "its just a theory" morons really are rather annoying and ignorant.

However, I must suggest that the ID or Creation-theorists are irrelevent. As long as they are prevented from shoveling their religion in schools, the point is moot and a matter of private conscience.

Can you not allow Creationists and ID'ers to wallow in their own ignorance? It is their right you know.

Please explain why it's called "The Theory of Evolution" when the theory hasn't been proven.

I think that they are ignorant of the meaning of theory. However, they are only using it as a disclaimer so that the person they are talking to is not offended and/or really pissed off by thinking that it was an honest belief of the ignorant "theorize"

Originally Posted by Mrs. M

Please explain why it's called "The Theory of Evolution" when the theory hasn't been proven.

No scientific theory can ever be "proven to be true". That is epistemologically impossible.

Science generally works on the theory that all theories are 'tentatively true' until proven otherwise. Gravity has not yet been disproven, ergo, we speak of the "theory of gravity". Likewise with the 'theory of evolution".

Seems simple enough.

And please note that a theory must be "falsifiable" or it cannot be considered scientific.

Originally Posted by Mad_Michael

No scientific theory can ever be "proven to be true". That is epistemologically impossible.

Science generally works on the theory that all theories are 'tentatively true' until proven otherwise. Gravity has not yet been disproven, ergo, we speak of the "theory of gravity". Likewise with the 'theory of evolution".

Seems simple enough.

And please note that a theory must be "falsifiable" or it cannot be considered scientific.

Which is exactly why using the word "theory" for something unproven has become socially acceptable in the lay world.

Originally Posted by Mad_Michael

Good doctor, I respect your view on this matter - the "its just a theory" morons really are rather annoying and ignorant.

However, I must suggest that the ID or Creation-theorists are irrelevent. As long as they are prevented from shoveling their religion in schools, the point is moot and a matter of private conscience.

Can you not allow Creationists and ID'ers to wallow in their own ignorance? It is their right you know.

You are calling large groups of people ignorant. This would imply that YOU know the whole story. Please fill us in.

Originally Posted by Mrs. M

Which is exactly why using the word "theory" for something unproven has become socially acceptable in the lay world.

First of all, please consider this in more general terms than the ones that you're using (evolution/creation), which will cause you to be unable to look at what I'm saying with any objectivity. If you want, consider the "Theory" of Gravity. Are you seriously attempting to suggest that laymen use the word "theory" to mean "guess" because gravity doesn't work?

Regarding your above comment, it is circular logic. You're saying that we should take scientific theories with a grain of salt becuase they are "just theories". Then you go on to say that they are "just theories" and this is why it makes sense to take them seriously.

The vernacular usage of the term "theory" does not have anything to do with whether or not certain branches of science are valid. This is like saying that the use of the term "cool", meaning both "good" and "cold, temperature-wise", should tell us that cold doesn't exist. You are suggesting that colloquial use of words should invalidate their original meaning.

Regarding your quip about calling it "The Theory of Evolution" when it hasn't been "proven" - I'll concede the point if you agree that the "Theory of Gravity" has not been "proven", nor has the "Theory of the Heliocentric Solar System". Theories are never "proven" - but this is really just a semantical cop-out used in a nonsensical way. If "theories" are just a load of crap, why do you express doubts when people tell you that the Earth isn't flat and that things fall up? After all, those are "only theories" and no one has "proven" them.

To reiterate what MM said, in a way that you will perhaps find less objectionable, no "theory" can ever be "proven" in the logical/mathematical sense of the word. When you hear someone say "prove a theory" you think that they mean that they are validating a guess (ie they walk in on Jones boffing his secretary and say "Aha!"). In logica/math/science, to "prove a theory" is to use a particular rule set to prove a hypothesis from a set of axioms, which is not possible in applied science.

In math, I can "prove" that if a = b and c = b then a = c by the property of transitivity. There is no such absolute with gravitation. We can observe that when we drop things they fall. We can record the speed and accelleration with which they fall. We can record terminal velocity as a function of drag. We can make predictions about falling bodies and show them to be bourne out every single time without exeception. But we can never, ever prove gravity in an absolute sense.

MM isn't just blowing smoke - for scientists, logicians and mathematicians, this is a distinction of paramount importance.

Originally Posted by Mrs. M

Which is exactly why using the word "theory" for something unproven has become socially acceptable in the lay world.

As is common, the lay usage is completely wrong. Nothing can be positively proven.

I think the logic would be comparable to me going to the doctor, having him feel my forehead and telling me, "You're quite cool." I then go to my friends and say, "Dude, I'm so cool! The doctor told me so - and he's a doctor, so you know it's true."

Also, for those of you who feel a need for scientific theories to be proven, how about an excercise in the nature of proof. Here's a simple "theory" - see if you can "prove" it.

Theory: The sun exists.

Proof:___________________