BBC Newsnight on evolution: Mind your language, and don’t say “theory” unless you mean it

Paxman“Evolution is a theory”, said BBC pundit Jeremy Paxman last night[1] to Alice Roberts, and when Prof Roberts tried to explain that it was only a theory like the motion of the Earth is a theory, he interrupted her to say that the motion[2] of the Earth is an empirical fact. Well, as Prof Roberts was finally allowed to say, evolution is also an empirical fact. So for facts’ sake, let’s stop calling it a theory.

I’ve said this before and I’ll say it again. There’s a war on between those who want to preserve our scientific heritage, and those who dismiss it as “materialism” and want to replace it with a view that they themselves call theocentric. These enemies of enlightenment are not stupid or WedgeTextwicked. They understandably want to preserve our reverence for human uniqueness, and misguidedly imagine that the only way to do this is to deny the indelible stamp of our lowly origin. For this reason, they will go to great lengths to misunderstand the science that tells us our real place in Nature, and to call the fact of evolution a “theory” is to invite just such willful misunderstanding.

In common language a theory always involves speculation and uncertainty. In academic discourse, it means a coherent set of ideas that explain the facts. Calling something a theory in this sense tells you nothing at all about how certain it is. A theory can be wrong (phlogiston theory), known to be approximate from the outset (ideal gas theory), very close to the truth but since improved on (Newton’s theory of planetary motions), or as certain as human knowledge ever can be (number theory in mathematics). Of course you can explain all this, but you should not put yourself in such a vulnerable position in the first place. It wastes time in debate, or in the classroom. It puts you on the defensive, and thus, paradoxically, confers legitimacy on the attack. It allows the focus to shift from what we know about the world to the words we use to talk about it. This takes us away from science to the domain of the philosophers, lawyers, and expositors of Scripture who are fighting on behalf of Creationism.

And so it distracts from what you should be talking about, namely the facts. Evolution, whether we mean changes in the genetic make-up of populations over time, or the common descent of living things on earth, is a fact. It is supported by, and explains, innumerable more specific facts concerning the fossil record, molecular phylogeny (the same kind of evidence that is used every day in DNA paternity tests), the frozen-in historical accidents of organs that have lost or changed their function, the distribution of species throughout space and time, and much more besides. Creationism cannot explain these, or any of the other facts of evolution science, except by appeal to the mysterious ways of the Creator.

Nor should we ever say that we “believe in” evolution. Believing always carries with it the feeling that disbelief is an option. Some members of the jury believe the witness, others don’t. Some people believe that Hillary Clinton will be the next President of the United States, but no one would say they “believe” that Barak Obama is the current incumbent, because no sane person doubts it. I don’t “believe in” atoms, or gravity, or quantum mechanics, because I regard them as established beyond dispute, although our notions about them will no doubt continue to change as we learn more. And exactly the same is true of evolution.

Should we ever refer to the “theory” of evolution? Yes, but not when we mean the fact that evolution occurs. There is a theory of evolution, but it is not what Jeremy Paxton seems to imagine it is. Genetic change and common descent are known facts, as well established from the fossil and molecular records as the order of England’s kings and queens is from the historical records. Mutation is a fact. There are theories (interlocking sets of ideas) about just how evolution happens. Natural selection operating on existing variation is a theory, so is neutral drift, so is punctuated equilibrium, and all of these are subsumed into the present-day theory of population genetics, the foundations of which were set in place in the 1920s, before we even knew the nature of the genetic material. All this and more goes to make up the modern theory of evolution.

So yes, there is a theory of evolution, but in the same way that there is a theory of chemical bonding. It is a theory about how it happens, not if. To take an analogy from chemistry, the quantum mechanical theory of bonding is about how atoms stick together to make molecules, not if. If someone were to deny that matter is in fact made out of atoms sticking together, we would regard them as ignorant, or perverse, or strangely misled, and the same is true of anyone who denies that we share a common ancestor with chimpanzees and bonobos.

Does it matter? Yes, it matters enormously. Creationists often maintain that evolution and Creation are both beliefs, whose respective advocates differ, not about observable facts, but about how those facts are to be interpreted. And they contrast evolution, as “only” a theory, with facts or even with scientific laws, in order to claim that it is far from certain and that views refuted over a century ago still deserve a hearing.

We should not, ourselves, be using words that help them do this.

Part of this post appeared earlier this year, here, but Paxton’s tactics give it new context and relevance, and my suggestion about when we should refer to the “theory” of evolution is as far as I know completely new.

[1] Newsnight, 16 June 2014; the sector on the teaching of evolution starts 29 minutes into the programme.

[2] Actually, he spoke of its roundness, but let that pass.

About Paul Braterman

Science writer, former chemistry professor; committee member British Centre for Science Education; board member and science adviser Scottish Secular Society; former member editorial board, Origins of Life, and associate, NASA Astrobiology Insitute; first popsci book, From Stars to Stalagmites 2012

Posted on June 17, 2014, in Creationism, Education, Religion and tagged , , , , . Bookmark the permalink. 17 Comments.

  1. Paul,

    I’m going to disagree with you.

    I’ve discussed evolution with many creationists and, in general, it is they that bring up the word theory first. Mostly in an attempt to diminish it. The usual terminology is “it’s just a theory”.

    In that context, I feel it’s really important to use the word theory and explain what it means and that it is an explanation for a large number of facts that are supported by evidence.

    I have started using the word theory intentionally because I feel it draws the conversation into a discussion about the scientific method and how we know what we know. I think trying to educate people on the scientific method is just as important as defending evolution.

    Creationists tend to jump about in discussions between many different fiends of science from cosmology to geology to biology and many others. I think bringing up the word “theory” at the start stops a lot of misunderstandings.



  2. We have the facts of evolution – we have both kinds of facts – those that cannot be true or false and those that can – both the facts comprised of objects, their properties, relations and associated events and too the facts comprised of propositions which are true or false whether or not they correspond or not to the first kind of facts.

    But what we also want are explanations for how those facts came about. Scientific theories are attempted explanations for the facts of both kinds – usually the second which are in-turn founded on the first.

    But all explanations are inferences. Such as when we speak of making inferences to the best explanation.

    All inferences start with the basic form “If P then Q” and finish either:
    1) P ergo Q
    2) Not P ergo not Q
    3) Q ergo P
    4) Not Q ergo Not P.

    Type 1 are actually assertions – analytic and a priori and so don’t speak of the world – they are how we define the world in question if regarding matters of facts of the first kind earlier above.

    Type 2 and type 3 are logically invalid forms – they cannot guarantee the truth of the propositions inserted into the place holders P or Q.

    Type 4 is logically valid but mistakes can still occur up at the semantic level making the inference unsound. For example, as Aristotle reasoned:

    “If the earth orbits the sun then there will be an observed parallax of the stars. There is no observable parallax of the stars ergo the earth does not orbit the sun.”

    Aristotle’s mistake was not at the level of logic, the syntax, it was up at the semantic level – his mistake was to assume that if there were a parallax of the stars it would be observable to the naked eye.

    For these reasons no theory can ever be known to be true since there is no inference that can be known to be sound, even if logically valid, until the thing inferred to is itself observed at which time no inference need any-more be invoked.

    Our current theory attempting to explain how the fact that life evolves comes about may yet be proved mistaken – but there is not mistake about the fact that life evolves – this is observed – ring species for example.


  3. @Alex
    You seem to be demanding that we produce the fabled crocoduck.. Rather old hat: like Paxman’s ignorance and the ACE man’s jaded arguments.


    • Hi Brian.

      Sorry, I’m not demanding anything. I didn’t know about the crocoduck until today, and it made me laugh.

      I’m not actually arguing that Evolution is wrong. I think I misunderstood a few things to begin with, however, my point remains the same. The crocoduck not existing does not prove Creation as a fact. It also doesn’t prove Evolution is wrong.

      What I’m saying is, you can’t say Evolution is an absolute fact. It is still a theory until completely proven. I’m not saying Evolution is wrong, I’m just saying it is hard to argue it as correct just as it is hard to argue that Creationism is wrong, even with clear evidence of Evolution.


      • Alex, you persist in misunderstanding the scientific use of the word “theory”; evolution is not “completely proven” but only in the way that no human knowledge is completely proven; so what? You can’t say evolution is an absolute fact like you can’t say the existence of atoms is an absolute fact, but the evidence is so utterly overwhelming that it would be most unreasonable not to accept it. As to what that evidence is, I have given you some detailed pointers, but must cut this subthread off here.


  4. Wasn’t Paxman playing ‘devil’s advocate’ – and trying to preclude more cries of ‘unfairness’ from the creationist camp – so as to allow Roberts to correct him? (I would agree that had Roberts first used the term ‘theory’ that would have been unhelpful.)


  5. Would it not be more honest and straightforward to admit that all human ideas are theories, and that some are better than others, and that a good counter-question would be to say “isn’t it best to judge ideas on the degree of evidence that exists for them and how well they sustain over objection?”

    Because it strikes me that attempting some kind of social-constructionist drive to ditch the language isn’t going to work (because the “isn’t it just a theory” question will still be beloved of evolution’s opponents) and looks a bit dishonest (because all ideas in science should be provisional).


    • No. Fact not theory that planets move in ellipses; we can see this. The theory of gravity tells us how this happens, by invoking the inverse square law. Fact not theory that human chromosome 2 is recognisably an amalgam of two ape chromosomes; we can even see the glue in the middle. If God had set out to make it clear to us that we share an ancestor with chimps, He could not have given a clearer signal.

      No one says that atoms in chemistry are uncertain because although all our knowledge of the world is in principle provisional, by now it is just silly to deny their existence. The same is true of the facts of evolution and has been for at least 80 years.


  6. This is an interesting article, Paul, but I still don’t see the evidence to Evolution that would take it away from being a theory. On News Night, Paxman was confronting Alice Roberts on it because she said it was absolute fact, when it is still a theory.

    Even though it is believed that we evolved from apes based on DNA and their similarity to us, there is no absolute proof that it happened. There isn’t a half human, half ape hybrid walking around that is the “missing link”. Until that is found, Evolution can not be proven as a fact.

    There is no question that life ‘evolves’. Creationists (who are not ignorant) and Evolutionists both agree on that fact. If God created life, then life has changed from the state it was in when it was created to what it is today. I am a Christian, but it doesn’t mean I don’t look at facts. It doesn’t mean I don’t want to find answers. It simply means, I believe that something created life. In my opinion, the big bang didn’t just happen by accident, something or someone caused it.

    No Scientist can prove what started the Big Bang. No Creationist can prove that God created the universe. They are both theories or belief systems until absolute evidence is found.


    • The existence of atoms was clear from the facts of chemistry for more than a century before we knew where atoms come from, and the existence of evolution was clear from the facts of biology for more than a century before the realisation that DNA was the genetic material. And neither chemistry nor biology attempt to explain the Bug Bang.

      I’m not sure what you mean by “half human, half ape”, but if you google Australopithecus you will come across more than a dozen distinct species that are clearly intermediates between us and our last common ancestor with chimps. And if you look at their skulls, you will have no difficulty putting them in the right order.

      And I really take exception to the suggestion that Christians aren’t evolutionists. We have prominent Christian advocates of evolution from Pope John XXIII through to evangelicals like John Houghton and Steve Chalke, and all denominations in between.


      • Paul, sorry, I don’t think my original post is very clear, there were some clear misunderstandings between us.

        First, I do believe that life has evolved since it came into existence. So I agree with you that some Christians are evolutionists.

        Second, in regards to the “half human, half ape” statement, that is what I’m looking for. Evidence that shows that man came from monkeys. I personally don’t see Australopithecus as enough evidence to prove this. They could simply be ancient species of primate that are now extinct and have similarities between Humans and Chimps. Again they could be the missing link, but I haven’t looked into it enough to know for sure so I will read up on it.

        To be honest I’m new to all this. Last nights News Night got me thinking into it seriously (I couldn’t sleep for thinking), so I googled it this morning and saw your post. What I think I may be misunderstanding is the difference between Evolution and The Big Bang. The fact that things Evolved does not prove that the Big Bang was not of God. Also, there is no evidence to prove that God does or does not exist. It is simply an unknown that we have no facts on, only theories, assumptions and beliefs.

        Evolution does not (in my mind) disprove Creation. Simply put, yes, life may have Evolved, but what started life in the first place? In my mind, God.

        So, what I’m trying to say is, let’s use Science to find the answers. But until we know for definite what created the Big Bang, surely it is not wrong to believe a deity created life (Creationism). Just as it is not wrong to believe that nothing exploded into something (the Big Bang). I think we can all agree that life has changed from the time it originally came into being.

        I think that is the point I’m trying to make and I’m sorry if it is completely off topic because of my original misunderstanding.


      • No, we did not evolve from monkeys. Apes and monkeys had a common ancestor over 25 million years ago. Humans and non-human apes had a last common ancestor probably around 6 million years ago. Check out the links at the Smithsonian on human evolution,, or even WEikipedia on human evolution, for about a dozen separate species showing progression from ape-like to clearly human ancestors; talk of a “missing link” has been out of date since the 1920s.

        None of this explains the origins of life, or proves the existence or non-existence of God, or has anything to do with the Big Bang.

        I most sincerely suggest Why Evolution is True (Coyne), Your Ineer Fish (Shubin; now available I think as a movie), or if you want a committed Christian expounding al this, Dennis Venema’s admirable Evolution Basics.

        And there I must leave it. Much for you – much for all of us – to learn and think about.


  7. (Excellent article, by the way.) 🙂


  8. Okay, fine. If we are not to use the words “theory” and “believe in” when discussing evolution, which words, then, SHOULD we use? I disagree that science should pay the price for the willful ignorance of those non-scientists who are incapable of understanding (or refuse to understand) the difference between the common and scientific definitions of the word “theory”, and those who intentionally exploit that fear of science.


  1. Pingback: BBC Newsnight on evolution: Mind your language, and don’t say “theory” unless you mean it - All the Heathens

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