Just a “Theory”

😡 I am really sick and tired of hearing “evolution is just a theory!” Knowing the difference between a scientific theory and our everyday use of the word theory is just basic scientific knowledge. Recently I have been having a hard time with creationists who want to argue with me. I am really getting bored with the “just a theory” bit. It seems to be the only thing that I hear anymore.

Biological scientists are nearly unanimous in their support of biological evolution as a fact!  The amount of evidence supporting this position is overwhelming. I’ve lost count of the number of times classmates of mine and grown adults have said to me, “Well, evolution is just another theory.” The late Stephen J. Gould addressed this confusion over twenty-seven years ago. His explanation is awesome! It’s simple and can be used to refute this ridiculous “just a theory” nonsense. I especially like what he says about gravity and apples. Here is Gould’s explanation:

In the American vernacular, “theory” often means “imperfect fact”–part of a hierarchy of confidence running downhill from fact to theory to hypothesis to guess. Thus the power of the creationist argument: evolution is “only” a theory and intense debate now rages about many aspects of the theory. If evolution is worse than a fact, and scientists can’t even make up their minds about the theory, then what confidence can we have in it? Indeed, President Reagan echoed this argument before an evangelical group in Dallas when he said (in what I devoutly hope was campaign rhetoric): “Well, it is a theory. It is a scientific theory only, and it has in recent years been challenged in the world of science–that is, not believed in the scientific community to be as infallible as it once was.”

Well evolution is a theory. It is also a fact. And facts and theories are different things, not rungs in a hierarchy of increasing certainty. Facts are the world’s data. Theories are structures of ideas that explain and interpret facts. Facts don’t go away when scientists debate rival theories to explain them. Einstein’s theory of gravitation replaced Newton’s in this century, but apples didn’t suspend themselves in midair, pending the outcome. And humans evolved from ape-like ancestors whether they did so by Darwin’s proposed mechanism or by some other yet to be discovered.

Moreover, “fact” doesn’t mean “absolute certainty”; there ain’t no such animal in an exciting and complex world. The final proofs of logic and mathematics flow deductively from stated premises and achieve certainty only because they are not about the empirical world. Evolutionists make no claim for perpetual truth, though creationists often do (and then attack us falsely for a style of argument that they themselves favor). In science “fact” can only mean “confirmed to such a degree that it would be perverse to withhold provisional consent.” I suppose that apples might start to rise tomorrow, but the possibility does not merit equal time in physics classrooms.

Evolutionists have been very clear about this distinction of fact and theory from the very beginning, if only because we have always acknowledged how far we are from completely understanding the mechanisms (theory) by which evolution (fact) occurred. Darwin continually emphasized the difference between his two great and separate accomplishments: establishing the fact of evolution, and proposing a theory–natural selection–to explain the mechanism of evolution.

– Stephen J. Gould, ” Evolution as Fact and Theory”; Discover, May 1981

You know, if a person does not accept evolution it does not magically change the fact that we are all “talking monkeys!” 



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  1. Joy Wang
    September 2, 2008 at 5:00 pm —

    Um, not to be a grammar nazi or anything, but, ” I am really getting board…” “bored”?

  2. Cassie
    September 2, 2008 at 8:17 pm —

    wow that’s embarrassing 😆 … thanks joy! fixed it!

  3. September 2, 2008 at 9:36 pm —

    Wow, we both must have had the same conversation over the weekend. My mom brought up Sarah Palin, and it got us started on how she wants creationism taught in the schools, and I scoffed (of course), and my sister-in-law thought best to inform me that “well, evolution is just a theory, you know!”. It’s extra funny, because I have my degree in Biology. I wonder how these same people rely on medical science when they are in need of a doctor, but they don’t give biologists and other experts in their field any credit for their knowledge. They must really wonder what I learned in university all those years! And if their creation myth should be taught, what prevents other creation myths from being taught? Surely we should include the First Nation’s ideas, the Polynesian’s, the African’s…

    Anyways, I only had time to state “yeah, it’s a theory like how gravity’s a theory” before my mom wisely changed the topic.

  4. MaggieMoo
    September 3, 2008 at 3:31 pm —

    thank the FSM that my friends who are religious are not creationists. They believe that there is a god, but they also KNOW that evolution is a fact and that we are just monkeys! In my Theory of Knowledge class, they are considering debating the evolution vs creationism argument. I’ll be sure to point the class to this blog-thingy if/when we do this debate. I’m worried about the 2 fanatical creationists in the class though. Knowing my professor, he would totally make them argue the evolution side! OH NO!!! Our research might actually go against our religious beliefs!

  5. Joy Wang
    September 3, 2008 at 4:28 pm —

    Whenever the just-a-theory justification gets trotted out, my eyes get glazed. It’s the oldest trick in the cdesign proponentist book. Except for lying, which encompasses this anyways. SJG’s awesome! Sarah Palin’s really, really stupid. I read some stuff on Pharyngula (I just got back from China and I’m trying to catch up w/ what I’ve missed in the month I’ve been gone) about the creationism thing–in politically correct terms, it would be ID, but nvm. I don’t know if McCain made a good choice that time, at least, if he wanted to appeal to the more…rational part of the population.

  6. Joy Wang
    September 3, 2008 at 4:31 pm —

    MaggieMoo: Your school lets you take classes like Theory of Knowledge??? That’s awesome! I can barely fit in my science classes before I graduate, let alone take cool stuff like Theory of Knowledge.

  7. Joy Wang
    September 3, 2008 at 4:31 pm —

    oh wait a sec… considering you said professor, i’m assuming you’re a college student. headdesk

  8. September 3, 2008 at 4:32 pm —

    Yeah, that saying spreads everywhere. Even my AP biology textbook is having to defend evolution from the saying “it is just a theory.” I don’t see other textbooks defending gravity, electromagnetism, mechanics, etc being “just a theory.” But nooo, evolution is always the exception, and just because it changes the way one views the world.

  9. Joy Wang
    September 3, 2008 at 4:49 pm —

    That might be something inherent about religion–it’s main purpose is to make people feel warm and fuzzy inside, and anything that threatens your fool’s paradise must be ignored. Idiotic, really. Evolution simply puts humankind in its place–one of many species that evolved gradually from primate ancestors, and ultimately, not anything special except for its ability to speak and write, and for causing the extinction of many other species.

  10. September 4, 2008 at 2:05 pm —

    @Maggie: debates with creationists are incredibly hard to win. Why? because you don’t actually have to have the truth on your side to win a debate. It’s one of the most frustrating things, in my opinion, to debate a creationist! To quote Stephen Jay Gould:

    “Debate is an art form. It is about the winning of arguments. It is not about the discovery of truth. There are certain rules and procedures to debate that really have nothing to do with establishing fact – which they are very good at. Some of those rules are: never say anything positive about your own position because it can be attacked, but chip away at what appear to be the weaknesses in your opponent’s position. They are good at that. I don’t think I could beat the creationists at debate. I can tie them. But in courtrooms they are terrible, because in courtrooms you cannot give speeches.”

    Ever notice how creationists don’t ever have to explain their theory? I never hear them talk about the strengths in their “creation theory”; I only ever hear them talk about the weaknesses in evolution. They go on the offensive, which is a great strategy for debate in this case. If you say nothing about your own theory, you never have to defend anything about it. Which they’d fail miserably at doing.

  11. Joy Wang
    September 4, 2008 at 3:27 pm —

    I’m taking Honors Chemistry right now–it’s the second day of class, and the teacher had to reiterate the definition of theory. Considering that most students have had (real) science classes for at least six or seven years now, I’d say that’s kinda embarrassing.

    Creationism can be summed up in three words (or one, depending on how you look at it: GODDIDIT!!!!!!!!!!!!!!!!!!!!!!!!

  12. MaggieMoo
    September 7, 2008 at 4:28 pm —

    No im not in college, but he is a doctor and stuff, and we enjoy calling him Professor Watson. It because we now have 7 class periods so that we can have the International Baccalaureate Program at our school. But yeah the program is going horribly wrong, but they wont let people not in the program take Theory of Knowledge (which was a very stupid idea cuz everyone should take this class)

  13. MaggieMoo
    September 7, 2008 at 4:31 pm —


    well these creationists barely talk to anyone who isnt christian, so i doubt they could win a debate on a side that they beleive in. oh! and it has been decided that they will have to fight for the evolution side. they are suuuppppppeeerrr pissed.

  14. September 8, 2008 at 6:00 pm —

    lol – will that ever be good for them!

  15. Cassie
    September 8, 2008 at 8:02 pm —

    omfsm! Evolution v.s. Creation debate! good luck with that! i soooo wish i could publicly debate some of the kids in my school on the topic…

  16. FFFearlesss
    September 10, 2008 at 3:54 pm —

    I’ve said this before, but I don’t think the way to approach this is to be antagonistic and looking to start an argument. A lot of creationists honestly don’t realize that the word “theory” holds so much weight in the science realm, because they’re so used to it being used as a fancy word for “guess” in regular life. Taking the time to explain the difference to them, nicely and rationally, may not convince them on evolution, but at least it will hopefully stop one more boneheaded comment that you need to argue.

  17. Cassie
    September 10, 2008 at 8:14 pm —

    You are right ferless. When I am dealing with creationists in person I am usually polite, hyper, but polite.

  18. scepticalchymist
    September 12, 2008 at 1:09 am —

    Well, what about telling these creationist weirdos “You know, creatonism is just a belief”.

    And you should not be too polite to creatonist…why not call them stupid, because that is, as a fact not a theory, what they are. Just tell the facts about them. They will not like you either, if you are polite.

    Of course, if you are possibly as bored as myself about such stupidity, then politeness is a nice thing to shorten the discussion.

    I wonder, why people, claiming to admire god’s creation do not even mind to read any science book in years, instead of their holy texts. If you learn math the probability seems higher to me, to learn anything more about “god”, than in reading the 2000 year old “wisdom” of archaic cultures. If it should be that old, read Euklid instead.

  19. FFFearlesss
    September 12, 2008 at 8:19 am —


    And you should not be too polite to creatonist…why not call them stupid, because that is, as a fact not a theory, what they are. Just tell the facts about them

    You could do that. And you could be right about a lot of them. But do you want to be right, or do you want to change minds? The fact is, especially at the high school level, a lot of people who don’t believe in evolution feel that way because they haven’t had anybody they respect explain to them why their thinking is wrong, calmly, eloquently, and without judgement. That’s how I was for years until a friend I respected convinced me to read a certain book that changed my whole outlook.

    You’ll never change the minds of people who are so ingrained into their way of thinking that they refuse to even entertain the notion that they might be wrong. But by being antagonistic from the outset, you miss the chance to change the minds of people who are actually open to being changed. That goes for any debate: scientific, religious, political.

  20. scepticalchymist
    September 12, 2008 at 9:10 pm —


    You’re absolutely right about “agnostic” people, people willingly to increase their knowledge, open for new ideas. And it seems to be always a good first question to ask, if someone admits the possibility that his or her viewpoint may be wrong. If there is not even the possibility of this, because “god” has told your opponent “the truth”, then any discussion is useless and will only do harm to your position. That means, the hard task would be to separate the lost from the ones where you have a chance for changing their minds.

  21. FFFearlesss
    September 13, 2008 at 9:02 am —

    Then again, you never know who’s mind you might change. I used to be one of those people who was “certain” that my ideas were true, but that was only because I had never had the “other side” explained by somebody who was actually intelligent AND patient with my ignorance. It’s hard to understand for those of us who actually seek out science information because it interests us, but for the average person, religious or otherwise, evolution is not something that comes up on the panel much. So your knowledge of it really doesn’t go much farther than “monkey into man”. And if you’re not naturally inclined to believe that because of religion, that really does sound implausible until somebody breaks it down into smaller pieces. Again, that’s what “converted” me. I read “How the Mind Works” by Steven Pinker which talks about the way evolution shaped various parts of our minds. Learning about evolution from an actual TANGIBLE example like that makes it easier to make that transition.

    Yes there are going to be people that, no matter what you tell them, no matter what the evidence, they are just going to fall back on “well that’s just what I believe.” But even then, I think the important part is to not fall back on antagonizing them, because while you may not convince them right then, but hopefully the seed has been planted and it may be the first thing to make them reconsider their views *down the line*. But if they’re turned off immediately because they feel like all Darwinists are “pains in the a**” it may make them refuse to consider any of their ideas just based on principle.

    I’m all about spreadin’ the love. 🙂

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