Logical positivism debunked (2): falsifications beat verifications – Karl Popper’s victory

In the Laundry. You are handed back your belongings all washed, and you notice that this is not your jacket. Actually you see your jacket hanging there right behind the manager. You point at it, yet he wants a plausible proof. “You say that this not your jacket? Yours is the one over there? Well, then you can probably state some details about that jacket over there before we look at it – details which only you should know.”

1966 Star Trek, Mirror Mirror Screenshot
Every laundry manager is well versed in Ludwig Wittgenstein’s Tractatus (1922) these days. Whatever you recongnise is recognisable on the basis of positive statements you make when you identify the object. The entire world as far as you know it, can be split into such sentences. If you were thrown into parallel universe – as it happens to Kirk, Uhura, McCoy and Scotty in the Star Trek episode “Mirror, Mirror” – you would realise that you could play the game of verification with this “your” world. A number of things are suddenly no longer the case in that strange universe: Spock for instance is now proud of a funny beard, to mention but the least precarious of all the differences. You might think with Wittgenstein’s opening passage of the Tractatus when you start stating the facts:

1        The world is everything that is the case.

1.1      The world is the totality of facts, not of things.

1.11    The world is determined by the facts, and by these being all the facts.

1.12    For the totality of facts determines both what is the case, and also all that is not the case.

Idealists will intervene with a lame standard complaint: “But words are so weak! Take the sound of a Stradivarius – such a sound can never be put into words!”

Which will not affect Wittgenstein. He did not really perform a “linguistic turn” with the Tractatus in 1922. Much of the early work is about why we can use visual images effectively as statements – as statements which one could just as well put into words. The visual image is just a faster and more efficient way to make statements about what we saw. The way from the image to the list of statements is more of a “digital turn” than a “linguistic turn”. The picture allows us to make statements about what should be the case if this was a true picture. All the individual statements we can make about the reality stated with the picture can be formulated as digital options of “yes, the case” or “no, not the case”. The idealist will intervene with a proclamation of that inexpressible depth that remains in any piece of art. Yet (to get back to that Stradivarius violin) with a good digital sound recording system we will be able to translate the finest interpretation of a Corelli sonata on such a Stradivarius into several megabytes of Wittgensteinian statements about what should be the case if that recording was a true recording of that specific sound and performance. The statements stored on the CD can be far finer than any vibration we might hear. The human ear is after all not much more than just another digital sound system. We will be able to produce the CD that delights the connoisseur as a superb recording of this sonata on a Stradivarius. (The idealist’s anger over Wittgenstein’s belief in the power of statements is ill-grounded anyway. The final passages of the Tractatus culminate in a number of thoughts about things which no fact-statement can claim to grasp. And here we find Wittgenstein rather humble to the dismay of the idealist who will defend far wider capacities of the human mind and intellect – we will need a third posting to touch these “metaphysical” fields.)

The devastating criticism of Wittgenstein’s totality of facts came from a quarter that could have embraced the thought. Karl Popper became the leading voice here with his attack of the – supposedly – rather useless project. Who should be interested in stating all the facts? The sciences? Henryk Skolimowski offered the following table of the different propositions in the controversy between Popper and logical positivism (as published in Paul Arthur Schilpp, The Philosophy of Karl Popper, The Library of Living Philosophers 1974, p.487) – my thanks to Bruce Caithness for this hint and these remarks:

What should we study in order to understand science? The structure of science The growth of science
What is the starting point of our inquiries? Facts and observation Problems
What are our basic conceptual units? Protocol statements Tentative hypotheses
How do we arrive at scientific theories? Alternatively, what is the process of the acquisition of knowledge? Simplifying the matter – Induction The process of conjecture and refutations, that is bold guessing followed by relentless criticism.
What are the foundations of knowledge? Is there indubitable knowledge? The rock bottom of knowledge are the basic facts given to us in immediate experience and expressible through protocol statements. There is no rock bottom of knowledge. All knowledge is tentative. The foundations of knowledge are piles driven into a swamp deep enough to carry the edifice of our pre­sent knowledge.
How do we distinguish scientific knowledge from nonscientific? The verifiability principle of meaning enables us to delineate the realm of scientific knowledge from non-scientific. The principle of demarcation delineates falsifiable theories which are scientific from non-falsifiable which are not.

It is easy to see why Popper should be right. Our personal experience should already convince us that we do not perceive lists of facts. Every single leaf on that tree over there can indeed be put into a statement about a leaf that is there now and that has not been there last winter. And yet I have no clue about the number of statements that create this picture, nor am I interested in this number.

The sciences – and that should have really troubled the logical positivist – are just as disinterested in the majority of facts. The application for a research grant will open with an attack of present research, which is, so the argument, unable to cope with specific facts. The researcher has to be creative with a proposal of a better model, theory, or paradigm and must promise to prove this better view with the requested funding.

It is then true that Popper defeated logical positivism?
Image source Jewish Online Museum http://jewishonlinemuseum.org/karl-popper
Karl Popper (image source Jewish Online Museum)

…in his Book The Logic of Scientific Discovery (1959). Well (if I have to give a clear cut answer on this question): no.

First note: Popper is interested in scientific theories where Wittgenstein is interested in statements of facts. Sounds like the same project but is not. A scientific theory, a “law of nature”, so Popper’s discovery, can never be verified. It can only be falsified

…which Wittgenstein must have read with a sigh of exasperation.

Ludwig Wittgenstein by Ben Richards (source: Wikimedia Commons)
Ludwig Wittgenstein by Ben Richards (source: Wikipedia)
Yes, exactly. That’s why a scientific theory is not part of the sphere of facts, and that is one of the points the Tractatus was supposed to make. A statement of a fact can be used to state an observation but we will never observe a law of nature or a scientific theory in action. To put it bluntly: You do not see gravitation entering the room and tumbling the object that is slowly tilted. What you see is that this object falls as soon as a certain critical condition is reached – again and again. Those who pretend that they see laws in action are rather on a religious mission:

6.371    At the basis of the whole modern view of the world lies the illusion that the so-called laws of nature are the explanations of natural phenomena.

6.372    So people stop short at natural laws as at something unassailable, as did the ancients at God and Fate.
       And they both are right and wrong. But the ancients were clearer, in so far as they recognized one clear conclusion, whereas in the modern system it should appear as though everything were explained.

All we see is that things happen rather regularly – and that is indeed what we can say as observers:

6.36    If there were a law of causality, it might run: “There are natural laws”.

Any specific regularities we claim to see, all the physical laws we present in mathematical and geometrical equations… are, if we experiment with Wittgenstein’s proposal, much rather aspects of the grid which we spread over the field of potential observations. We create grids (such as the grid of geographical coordinates) so that we can state observations under their regularities. The grids themselves are neither true nor false (they are, if we argue with Ernst Mach and Heinrich Hertz more or less useful as patterns which we can use to describe the patterns we perceive).

That is the first thing then to remark about Popper’s attack: it is not on Wittgenstein’s topic. It refutes Wittgenstein, where Wittgenstein does not claim anything else.

Popper speaks, secondly, about how we should organise the sciences. He proposes to streamline the production of scientific theories. Wittgenstein is at the same moment hardly interested in our organisation of the scientific community – and if he were he would not see it as part of the descriptive project he is discussing in the Tractatus. If this particular book is successful it will make us aware of the line between statements of facts and the far wider range of rather “metaphysical” statements such as “laws of nature”, “scientific theories”, “mathematical equations”, “predictions of logic”, ethical and moral maxims. They are all, strictly speaking, metaphysical, not part of the physical observations of objects, motions etc.

Popper’s and Wittgenstein’s projects do not really contradict each other – at least not where Popper wants to contradict. Work in the sciences will be under Popper’s guidance just as fact based as under Wittgenstein’s. Our instruments do not bombard us with Popperian falsifications but with positive data. The Hubble Space Telescope is transmitting positive data which we interpret with Wittgenstein: We should be able to say “what is the case” if these data were correct. The work of the scientist (even the work of the historian who is not allowed to be a scientist in English) is fact oriented. We make statements any observer would make if he or she had to evaluate the same materials – and we add interpretations with an awareness of their status as interpretations.

As a historian with a focus on the history of knowledge I would add that Popper was clearly writing under the spell of the mid-20th-century paradigm of paradigm shifts. It is nice to use this paradigm where we want to produce streamlined histories of epochal discoveries. The entire perspective is otherwise rather misleading. The Copernican revolution is mostly a 19th century paradigm shift projected back, though, into the mid-16th century. Copernicus did not really refute Ptolemy. The refutation came rather late in 1851 with Léon Foucault’s experiment, that proved that our planet is actually rotating under the free swing of pendulum (if that pendulum is long and heavy enough, swinging in straight lines, and not hanging above the equator). Copernicus was personally – we might assume – far more interested in astro-medicine, a field in which he wanted to see the life spending sun in the centre. The refutation of the Ptolemaic system could wait for another 300 years, it was actually not needed to make the Copernican system attractive. The heliocentric system was attractive as it allowed far better computations of incoming observational results. And academic studies as they continued at Europe’s universities? – remained ambivalent about the entire story. They remained focused on the four faculties of theology, jurisprudence, medicine and classical learning right into the 19th century. The modern nation state with its interest in repositioning the citizen on secular grounds – as an independent entrepreneur, scholar, researcher, engineer, and industrialist, invested in the scientific revolution… all which does not really fit into Popper’s picture. Popper is normative where he pretends to be descriptive; he is immersed in politics; he tells us how we should organise the sciences.

Léon Foucault's experiment that proved the earth's rotation – refuted Ptolemy late in 1851 when Copernicus was already fully established. We accept theories that work well with positive facts, and that is what Copernicus and Kepler offered in the 16th century.
Léon Foucault‘s experiment that proved the earth’s rotation refuted Ptolemy only as late as 1851 when Copernicus was already fully established. We accept theories that work well with positive facts, and that is what Copernicus and Kepler had offered in the 16th century.

Wittgenstein is on the other hand rather decided to push all statements about what we “should”, “ought”, “could” or “might” want to do (whether we make these statements as private individuals, as advocates of the sciences, or as or as religious leaders) into the sphere of ultimately arbitrary enunciations of our will not of facts.

It is eventually not even clear whether Popper could indeed tell the sciences where to go. Big data might become a key to far finer observations and to unexpected paradigms. Computers might do the rather trivial job of searching for patterns. And that again is something Wittgenstein tried to explain: Facts are a rather trivial subject matter.

Exposing pseudo-science – where Popper actually was extremely successful

Popper has been extremely helpful in one particular confrontation: The confrontation between the sciences and modern pseudo-science – he himself was immensely interested in conspiracy theories as a phenomenon of the The Open Society and Its Enemies (1945). Bill Nye used Popper’s argument when he asked Ken Ham what sort of fact he would accept as a refutation. Ham did not see why this could be so important. He would, of course, not accept a single argument against Young Earth creationism. If geologists, astronomers or palaeontologists present “facts” against creationism Ham will continue to say that they have to be interpreted in the light of creation science until they fit. Such objects and facts remain puzzling artefacts until the creationist has integrated them into the paradigm of a 6000 year history of the universe. The advocate of modern sciences, Nye, was on the other hand, extremely relaxed – not at all afraid of refutations, rather eager to get them and to see what will come then. He would accept any fact, whether geological layers with the bones of men and dinosaurs, or archaeological sites that proved that man and dinosaurs actually lived together as we learn in Ham’s museum, whatsoever…

Pseudo-science is bullet proof by design, is science under the jurisdiction of its advocates. Real science is open. But that again is something Wittgenstein had already declared on the far deeper level of statements of facts. Any statement of a fact can be the case or turn out to be not the case. Observation has to show whether or not a proposition is the case. Any true observation will remain independent of my will.

6.373 The world is independent of my will.

The deliberate misunderstanding

It is clear why Wittgenstein had to argue with the totality of facts. The Tractatus tries to draw a line between what we can and what we cannot state as positive knowledge. If we want to understand this demarcation line we have to consider the entire project – the project of depicting the entire world as we perceive it through statements of facts. To know what we can do with such statements does of course not mean that we actually have to state all these facts. A camera is not the moral imperative to take all the pictures it allows us to take. And Wittgenstein’s call to limit the philosophical debate to the sphere of facts is at the same moment no moral imperative to state all these facts (it is also no proclamation that all other conversations are from now onwards forbidden – they just should not pretend to be explorations of facts).

Wittgenstein’s perspective on the demarcation line between positive assertions and metaphysics surprise on both accounts: Whatever we can identify can be put into statements of a facts. As soon as this is understood, we can concede that statements of facts create only a limited field of statements. Logic, mathematics, the individual laws of nature, our scientific theories, all our notions of causality, of the future, of ethics… all that is strictly speaking “metaphysical”, beyond the level of physical observation.

Popper argues – if we read him with Wittgenstein – on metaphysical grounds. We might organise the sciences with Popper with the aim to get the scientific results Popper promises. Wittgenstein would respond that we can otherwise also do anything else. Become peasants and stop this business of the scientific exploration altogether. Popper is useful within the agenda he establishes, but the agenda is no factual requirement. We can imagine worlds without human research.

Is Popper’s attack of logical positivism a deliberate misunderstanding? Did Popper just not get that Wittgenstein was interested in why we can use sentences, images and sound recordings in a descriptive project?

In a way Popper used logical positivism as an almost ideal opponent within the scientific community, as an opponent he could discredit and who would not even react. On the strategic level we might assume that Popper would have otherwise fallen into the very category of positivism which he tried to discredit with such vehemence. Stephen Hawking is a terrible author when it comes to this danger – ready to pose as a positivist himself and ready to take Popper into this very boat. Hawking in his The Universe in a Nutshell (p. 31):

Any sound scientific theory, whether of time or of any other concept, should in my opinion be based on the most workable philosophy of science: the positivist approach put forward by Karl Popper and others. According to this way of thinking, a scientific theory is a mathematical model that describes and codifies the observations we make. A good theory will describe a large range of phenomena on the basis of a few simple postulates and will make definite predictions that can be tested […] If one takes the positivist position, as I do, one cannot say what time actually is. All one can do is describe what has been found to be a very good mathematical model for time and say what predictions it makes.

Links & More

  • Karl Popper, Logik der Forschung (Frankfurt am Main: Mohr Siebeck, 1934) rewritten as The Logic of Scientific Discovery (London Routledge, 1959). pdf
  • Karl Popper, The Open Society and Its Enemies, 1-2 (London: Routledge, 1945). Wikipedia
  • Ludwig Wittgenstein, Tractatus Logico-Philosophicus, translated by C. K. Ogden (1922). Gutenberg
  • Shirley Gregor, “The lingering death of positivism, Chapter 1. The struggle towards an understanding of theory in information systems” (2004). http://press.anu.edu.au//
  • Henry Folse, “Comments on Popperian Falsificationism” http://www.loyno.edu/

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One Reply to “Logical positivism debunked (2): falsifications beat verifications – Karl Popper’s victory”

  1. Nice back and forth between the W’s Tractatus and Popper, and without the violence of a fire poker!
    Ayer himself I thought ‘debunked’ the thought’s movement the best, and most thoroughly, as he was deep on the inside. In the end he recognized how James was closer to articulating what Ayer referred to as ‘the spirit’ of LP, that ideas should be examined for their cultural ‘cash value’. People paint Rorty as some rebel against what became Analytic Phil (LP), but the movement was headed towards his conclusions even in Ayer’s reflections.

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