Popper’s victory

Just been walking to work listening to Start the Week on my dPhone. Rather jolly as it featured Mark Henderson (wants more Geekdom in Government), David Nutt (kicked off advisory committee for speaking truth to power re drugs) and David Blunkett (weird mixture of refreshingly blunt and creepily political). Mark made a big point of the idea that we need not just to encourage the spread of scientific knowledge, but to cultivate the habit of scientific thinking : a certain approach to critical problem solving. Quite right too, but reminds me of the debate last week on Telescoper’s blog about whether we should be teaching Physics knowledge, Physics understanding, or Physics skills.

The related point, picked up and run with by the Marr, was that the striking thing about scientists is that they are always trying to prove themselves wrong. Popper-style bollocks. Why has this become the official philosophy of science ? Science progresses by people relentlessly chasing down ideas and facts within a safe framework. You can’t go trying to prove yourself wrong every day. That way lies madness. We change our minds either when some striking new fact accidentally emerges, or after years, as the evidence piles up and can no longer be squeezed into the theory : and then there is a BIG change. I guess you can tell that my instinct is closer to Kuhn, but even then only as a sociological description, not as a philosophical position.

I do understand the debating point; and clearly scientists are more open to change than politicians. But whats the fundamental point here ? Is it that as a point of principle we like proving ourselves wrong ? No. Its that we are committed to arriving at true knowledge. Scepticism is only one of several things in our armoury. Maybe its about timescales. The success of scientific research over four hundred years means that – at least as far as the behaviour of the physical world is concerned – moment by moment scepticism is almost pointless. But scepticism over years remains hugely important.

In case people think I am making an anti-scepticism argument, I see this as a practical issue, not a principled one. Where we do not yet have a sound underlying theory – eg human behaviour – moment by moment scepticism is very valuable. But do we really think every physicist wakes up each morning and says to herself : “Now, how can I go about proving Einstein wrong today”. Give us a break.

26 Responses to Popper’s victory

  1. Tony says:

    Good point, Andy. I suspect, in this sound-bite culture of ours, that the idea that scientists are always trying to prove themselves wrong has arisen as an easy concept to sell in opposition to discovery by revelation and other non-empirical means of seeking knowledge.

    Also, it seems that scepticism is still rife in our world, but rather than being sceptical about snake-oil merchants and others who can offer no proof to their claims, people seem to prefer being sceptical of anyone who is considered intellectual (ie, has letters after their name) even if, or especially if, they have a mass of evidence to support their claims.

  2. You raise an interesting point.
    I’m no scientist myself so please forgive my naïveté, but surely very few scientists think their theories are absolutely correct? Isn’t it more usually the case that a scientist puts forward a new theory as simply a better approximation than those that have come before?
    So is not the practical application of Popper’s philosophy less a case of trying to prove one’s theories wrong as trying to prove one’s theories are not quite right?
    In that sense I think Popper is still relevant.

  3. andyxl says:

    Mike – one point is that science is not a set of isolated hypotheses, but a complex tangled web of them. A simple hypothesis may be relatively easy to disprove, but a “theory” is typically not a simple yes-or-no logical statement, and testing the consequences of a really deeply embedded theory requires lots of anciallry assumptions. I will try to knock up a post on this sometime…

  4. Aleks says:

    In this context, the Lakatos concept of a theory, which is surrounded by auxiliary hypothesis is important – a theory is predicted by falsification by all kinds of supporting statements. For example, Newtonian dynamics is not falsified by the rotation curves of galaxies, because it is protected by the auxiliary hypothesis of dark matter. The naive version of falsification always never applies in the real world (and Popper knew that very well).

  5. Hi Andy,

    On the “Popper-style bollocks” thing. We do, as you say chase down facts within a “safe framework”, but surely when we get a result, make an observation, we should be trying to hammer away to find reasons that it might be wrong. Only if it survives them do we publish. Certainly that’s the way the collaborations I’ve worked on behave. And the main criticism of e.g. OPERA is that they didn’t do it hard enough…

    This is moment-by-moment scepticism and its vital. Just as much when your framework is “safe” (standard model etc) as when it is not…

    It’s not scepticism about the whole theory science moment-by-moment – that’s longer term, as you say. But we particle physicists at least do spend a lot of time looking for physics beyond the standard model. i.e. trying to prove our best theory wrong.


  6. andyxl says:

    Jon – its only Popperianism as a kind of philosophical sacred cow thats annoying. W.r.t. moment by moment practical scepticism about your own work – yes absolutely. Some of us ex-Leicester folk refer to “Willingale’s law” which is “if you’ve done it once, you’ve done it wrong”. But I don’t see this as a special “scientific method” thing. Its just what anybody should be doing in any practical but difficult subject. (Dick W was referring to software rather than hypotheses).

    • “Its just what anybody should be doing in any practical but difficult subject.”
      Like politics and economics? But I doubt they (all) do. Agree that it’s not just scientists. Engineers, and probably Lawyers, do it too…

  7. Norman Gray says:

    Andy said:

    > Why has this become the official philosophy of science ?

    I think because it’s become the official viewpoint of official philosophers of science, who are generally a lot more interested in formal logic and in exotic epistemology, than in science. As far as I can see, the thing that (anglo-american) Philosophers of Science study is a thing which is quite absorbing and perplexing, but has rather little overlap with science.

    Popper’s contribution was to note that falsification is asymmetric. No quantity of corroborations can verify a hypothesis (the fact that the sun has come up on earth every day for the last billion years does not strictly imply that it’ll come up tomorrow; induction is logically insupportable), but a single falsification can disprove a hypothesis. This is all logically fine and dandy, but Popper seems to have gone from saying, “this is logically coherent”, to “science could work this way”, and thence briskly to “science does work this way” and finally “science should work this way”. His meta-intention was to find a defining criterion for science which both marxism and freudian psychoanalysis fell on the wrong side of – that is, to deny their proponents’ claim that both of these are sciences and so should inherit science’s authority. It seems that Popper was eventually persuaded that this was an unrealistic distinction – there are probably no subjects which are Sciences by Popper’s criterion – and that he weakened the criterion again and again under criticism from Lakatos and others, but without ever quite discarding it.

    Philosophy of science textbooks start thus: chapter 1, Introduction; chapter 2, Naive realism (in which a naive notion of realism has the stuffing comprehensively kicked out of it, with glee); chapter 3, idealism, …. That is, they never seem to consider the problems of developing a sophisticated realism, but simply bustle on past into the crystal delights of logically consistent idealism. Myself, I feel that science is fundamentally realist, and scientists are fundamentally realists, and that a ‘philosophy of science’ which doesn’t deal with this is simply not a philosophy of any actual activity labelled ‘science’.

    Kuhn and co are disparaged as ‘sociology of science’, but I think Kuhn has a lot more to say about actual science than has Popper or anyone who follows him. The people who do the ‘sociology of scientific knowledge’ (google ‘SSK’ or ‘strong programme’) are attempting to work out how it can be that an activity so messy and human and personal as science actually is, can so consistently generate new and reliable knowledge. These are the people that are attacked as making statements that that aircraft being able to fly is a social construct, but that’s a silly caricature believed only by foolish people of a Dawkins stamp.

  8. Albert says:

    Indeed, scientists rarely try to proof themselves wrong. The game is to proof someone else is wrong.

  9. Clive Page says:

    I think the most important thing from Popper’s work is that it make it possible to distinguish between a scientific theory, and a non-scientific one: basically a scientific hypothesis must be falsifiable. I think this distinction informs a lot of current debate about bleeding-edge theories or hypotheses. Take for example String Theory. I know very little about String Theory except what is written in popular magazines etc, but I do know that if it is to be taken seriously it has to make predictions that are testable within the forseeable future. I think most people involved would agree with that, and for that reason Popper’s work is very valuable.

  10. Alan Heavens says:

    Practical application of the scientific method is more probabilistic than the assertion of proving theories wrong suggests. One can address the question of which theoretical model is more probable, given the data we have (and some prior position – always nice to acknowledge one’s own prejudice in this), and the collection of some new data will vary those relative probabilities. A new experiment may make a theory less likely, relative to other candidates, but it may also make it more probable. To say we are trying to prove ourselves wrong all the time is therefore wide of the mark (probably).

  11. andyxl says:

    Alan : I was hoping a good Bayesian would chip in. We have all been confused since Hume showed that empirical knowledge is impossible, whilst our instinct is that we gradually know more. The solution must be a probabilistic approach to knowledge. Who was it said all this ? Carnap ? Too sleepy to remember

  12. Michael Merrifield says:

    Wasn’t the point that was being made that the general public often do not appreciate the fact that the scientific method always involves a hefty dose of attempted falsification?

    If this basic philosophy is not appreciated, the fact that scientists are, for example, busily trying to test theories of climate change to destruction is in real danger of being popularly misconstrued as “proof” that there isn’t currently a broad consensus on the subject in the scientific community.

  13. John Peacock says:

    Andy: I agree that Popper didn’t describe at all well what most scientists do, most of the time. But skepticism is still the key to why the subject thrives: not just worrying all the time that you’ve goofed and wanting a cross-check as reassurance, but also examining critically ideas advanced by others, independent of their eminence.

    But actually, to slightly contradict myself, I do perceive that astronomy is a bit less argumentative than it used to be. If you compare Ryle and Hoyle tearing each other to shreds in public back in the Good Old Days, it seems we’re more polite these days. This can go too far, as it may lead to a complacency where possibly dodgy assumptions go unchallenged.

  14. andyxl says:

    I’m just disappointed nobody asked me what a dPhone is.

  15. Clive page says:

    Next question Andy (which I’m sure you want us to ask): how do you listen to Radio 4 on a dumb phone?

    • andyxl says:

      Even though it only cost fourteen pounds, it can play mp3s and has a radio. But no apps or android or web or any of that stuff.

      • Norman Gray says:

        Well, what’s the point of such a phone?

        I mean, my phone’s got a telephone app, too — it’s quite cute, as it means I can communicate verbally with people who are spatially remote — but if I want to talk to people in that way I’ve got some kit at home which can do the same, better. So the phone’s telephone app is rarely used, and it would work just as well if it were missing. I don’t know why they bothered factory-installing it, to be honest.

        And MP3s? Nice, but I don’t think it’ll catch on.

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