In conversation with Nicholas Maxwell
“Observe!”
The room looks back at him in silence.
“Observe what?” someone eventually asks.
A sly smile grows across Karl Popper’s face. “Exactly!”
As rumour had it, Karl Popper liked to begin his seminars this way – with this cringe worthy, smug, academic stunt that is now a firm part of the folklore and myth surrounding the man.
Paddling upstream against intuition, Popper needed something of his own, something “very simple, very basic, very elementary” that would get his message across. Inductivism, the claim that we acquire knowledge about the world by observing it, was an idea that should have been dead and buried long ago. And its death was central to everything Popper was trying to build and explain.
But everywhere he turned, inductivism was still there, holding firm in the minds of people who should have known better. It just seemed to make sense. Long, careful, abstract arguments weren’t doing it, so instead Popper found something fast and gimmicky, something that was easily understood and which could help to shatter that intuitive barrier.
Those people watching Popper as he commanded them to “observe” knew immediately that something important was missing. With any glance in any direction, there are infinitely many things to see, feel, hear, touch, smell – enough observations in a single lecture hall to fill a lifetime. So a filter of sorts must be there before anything is specifically noticed. You need a problem, something that draws your attention (you need to know what Popper is referring to) but you also need a huge array of background theories to even begin to understand what you are looking at.
To make use of an old, worn, philosophical cliché, even if he were asking you to simply look at a red cup, you would still first need theories about what water is, what drinking is, why a cup is used, what problem it solves for people, what the colour red is, what colours are… Theories always come first, they give us our eyes and our senses. Without theories the world is an incomprehensible mess of light and movement and noise and objects and behaviours – we are newborn babies once again, or worse!
Watching in the audience all those years ago at the London School of Economics (LSE), was a young professor recently hired to run tutorials for Popper’s lectures. But when the news filtered up that Nicholas Maxwell was on the payroll and working in his department, Karl Popper was “furious”.
The two men had clashed previously at another seminar, where Maxwell became quickly besotted with the older philosopher, who it seemed couldn’t open his mouth without saying “really interesting things”, things “at odds with all the usual rubbish”. And yet someone who was also “fairly terrifying”, with it not uncommon for guest presenters to collapse inward, “reduced to tears” by the remorseless criticism that Popper would hurl at nearly every sentence from their mouths – a uniquely “harrowing experience”.
At the head table, sandwiched between Popper and his assistant John Watkins, Maxwell listened as they argued across him, about his ideas. He would manage to get a few words out, and then “Popper would interrupt”, Watkins would then interrupt Popper, and Maxwell would sit silently for the theatre to playout. Soon the two men would turn – breathless and exhausted – back to their guest and ask for some clarity, which would quickly set them off again.
After a few hours of this, Maxwell laid-out a theory of the mind that seemed to hit the limit of Popper’s patience. The older philosopher stood up in anger and – near-yelling – demanded to know how on earth he came up with such a ridiculous idea. Maxwell shrugged and replied in the deepest of Popperian language: it was “a bold conjecture!” Through the laughter of the room, Popper could be heard muttering under his breath: “it’s not so bold as all of that!”
All truth seeking starts with a problem, and Maxwell’s problem has to do with falsifiability. Popper’s great breakthrough with the philosophy of knowledge was to show that our truth-claims about the world can never be verified, never proven correct. Instead what we do is create theories, then burrow into those theories to produce experiments, and then derive predictions about what we will see and what will happen. Here we test and test and test, hoping for error. No amount of positive predictions can ever confirm a theory, but it only needs one incorrect prediction to falsify a theory.
When something is shown to be wrong in this way, it leaves a burden upon us all – we need to create something better. This, for Popper, is how science and knowledge advances, this is how we make progress: through conjectures and refutations.
This is also where Maxwell senses that something is off, that something is missing, something important. It runs like this: let’s say that you have a theory that has just been falsified, and so you are searching for a new theory that better accounts for what you are seeing in reality, well how do you choose? There are infinitely many rival theories that can be thought up, all of which explain our observations.
Popper’s answer was empirical content: pick the theory which predicts more than the others, and which explains more phenomena. But this still doesn’t fix our problem. We can increase the empirical content of a theory simply by asserting “ugly”, “hodge podge”, “bizarre” add-ons. Instead of Newton’s theory of gravity, we could create Newton’s theory of gravity plus the claim that in the year 2050 it will change from being an attractive force to a repulsive one, and we will all “fly off the earth”.
It is an absurd theory, so absurd that it will never even be tested, but it does predict more, and it does have more empirical content, “exactly the criteria according to Popper that should lead us to accept this theory”. So what makes us reject this type of ad hoc theory? Unity! Or rather disunity! We want our theories to apply to all things, universally. This, for Maxwell, is what Popper (and so many other philosophers) missed or ignored. An underlying metaphysical assumption within science that values unified theories over dis-unified ones, regardless of how empirically successful they are.
Popper’s demarcation doesn’t allow a place for metaphysics within science (“for Popper the basic aim of science is truth, nothing being presupposed about the truth”), but he does recognise a problem of sorts here. His answer this time is simplicity. Across his work, two such versions emerge (one from his earlier work and a later, more ambiguous one from Conjectures and Refutations), but essentially they amount to either the unsatisfying and counterintuitive claim that the more empirical content that a theory has – “what it says about the world” – the simpler it is, or that we “should leave it to scientists to fight for their theories”. As Maxwell notes, these are notions of simplicity that seem to create complexity, horribly so.
Rather Maxwell wants to start where we know we are already, with what “actually operates in physics” and with “what physicists seek”. Instead of pretending that this preference for unity isn’t there, we need to make it explicit – thereby making it into something that we can improve along with the rest of science.
In this enterprise the basic aim of science shifts as well, from Popper’s notion of truth without presupposition to instead “discover[ing] the underlying unity in nature that we presuppose, and we have to presuppose in order to proceed, exists”. And so a map of sorts begins to develop, a way to not only understand which theories are likely false, but also which ones we should be pursuing into the future. Something that Maxwell develops into a methodological hierarchy, or aim-orientated empiricism.
It runs from the claim that the universe is at least partly knowable – “if that is false we have more or less had it whatever we assume” – down to evidence and our currently accepted, fundamental, theories such as Einsteinian relativity and the Standard Model.
Those assumptions near the bottom of Maxwell’s ladder are much more substantial, and also much easier to revise once new knowledge is developed. While higher-level assumptions are less substantial but also more likely to be true. It also becomes a two way progression up and down the ladder, as the latest breakthroughs in knowledge also improve our means of finding knowledge itself, as we see with the creation of instruments such as microscopes or telescopes.
And it isn’t always the case that evidence influences theories – sometimes it is the theories that influence evidence (most obvious when experiments have been mishandled). This is an important aspect of aim-orientated empiricism because it accounts for the possibility of new theories changing our metaphysical assumptions. As Maxwell accepts, we don’t actually know that the universe is unified, or that a theory of everything is on its way, it’s all a “massive assumption”.
But by making our metaphysical assumptions explicit, and then stretching criticism all the way up to their door, Maxwell is trying to increase the size and the quality of possible refutations, and so with them possible improvements. He is, in his own words, being “more Popperian than Popper”.
Thomas Kuhn was another contemporary philosopher who had a talent for angering Popper. The change that Kuhn wanted to make in this whole picture of scientific discovery involved a deeper look at the history of science, and a firmer understanding of the behaviour of scientists. He presented it like this: sure, occasionally science looks very Popperian with everyone working to prove existing theories wrong and with grand shifts in the landscape of thought (“revolutionary science”), but most of the time something very different is happening. Day-in day-out your average scientist is not trying to disprove the current paradigm or consensus, but is actually working to strengthen it (“normal science”).
It is an emphasis that Kuhn thought was fundamental, and which Popper dismissed as both trivial and dangerous at the same time. Seeing it as a risk not only to science but also civilization, Popper was horrified that someone would want to encourage others into the mundane grunt-work of normal science; into a life without critical thought and hard questions. He also didn’t see much originality in the idea, flippantly saying that it was something “I discovered anyway long before Kuhn did”.
In this argument between the two most influential philosophers of science, Maxwell’s sympathies are firmly with Popper. Everything should, at all times, be open for criticism. In fact aim-orientated empiricism tries to show that unquestioned paradigms do exist, none more pressing than the assumption of unity which is built deeply into the whole enterprise of science. But it also explains the need for revolutions… more revolutions… more times and in more ways. Again, Maxwell in his own words is trying to be “more Kuhnian than Kuhn”.
The man who hired Maxwell at the LSE without consulting Popper, Imre Lakatos, tried to blend the ground between Kuhn and Popper by talking about the place for “provisional” refutations between research programs. It is appropriate to always question our theories and try to prove them wrong, and we should never accept paradigms (or the “hard core” in his own terminology) but neither should we expect rapid shifts in scientific direction. People need time to change their minds, and to judge the errors within theories, it just cannot be as absolute and as sudden as Popper hoped for.
Lakatos’ framework is still profoundly Popperian, and so different from Maxwell’s, but by imagining that a hard core for the whole of science was possible, there is a pre-echo of aim-orientated empiricism within his work. So perhaps also more Lakatosian than Lakatos?
With something this lavish, the criticism also – necessarily – comes thick and heavy. And it tends to look like either:
1. There isn’t in fact a unity underlying all of science, just the appearance of it; or that unity is only a novel aspect of physics, and not of science in general.
2. That the unity we see is a result of science, not an a priori aspect of it. Science only reveals a unity in nature, not the other way around.
3. That by imagining all un-rejected theories (“infinitely many ad hoc theories”) to be still reasonable possibilities of science – even when they appear absurd and are not taken seriously – Maxwell is looking for a principle that allows for them to be excluded (unity), and so he is making the mistake of justificationism. He wants a reason for the ridiculous to be rejected, rather than just allowing that they are ridiculous.
This last criticism is the weightiest and most often repeated. It is also the one that Maxwell admits “does baffle me”. A former student of Popper’s, and a firm defender of critical rationalism, David Miller, picks up on a single phrase from Maxwell’s writing to show this justificationist element: “in effect”.
In persistently excluding infinitely many . . . empirically successful but grotesquely ad hoc theories, science in effect makes a big assumption about the nature of the universe, to the effect that it is such that no grotesquely ad hoc theory is true, however empirically successful it may appear to be for a time. Without some such big assumption as this, the empirical method of science collapses. Science is drowned in an infinite ocean of empirically successful ad hoc theories.
Miller remarks:
The words ‘in effect’ here are tendentious. Since scientific hypotheses in modern times never mention God, it might be said that science ‘in effect’ makes ‘a big assumption’ of atheism. But it does not make this assumption, and many scientists privately assume the opposite. Hypotheses that bring in God are simply excluded, rightly or wrongly, from empirical consideration. That does not mean that they might be discussed non-empirically, as indeed they are being discussed in this paragraph.
There is an old joke that Miller uses to better explain this. A guy a walks into a bar in a busy part of town and orders a beer. Soon he starts to snap his fingers, over and over. Eventually the bartender asks him “why are you snapping your fingers?” “Because it keeps the elephants away”, the guy answers. The bartender looks around the crowded bar bemused, “but there aren’t any elephants here”. The guy smiles back at him, “See, it works.”
Where Maxwell wants some sort of interdictive behaviour to explain why there aren’t any elephants near the bar, Miller thinks that even if snapping ones fingers did indeed keep elephants away, it wouldn’t be needed to keep them away from that bar, nor bars in general. It is enough to simply say that elephants rarely enter towns and rarely, if ever, go near noisy bars. No more explanation is needed. In Miller’s view, despite us seeing unity and tidiness in our theories, we should still hold that science “assumes neither that the world is tidy nor that it is untidy”…“I shall change my mind about ‘the true unified theory of everything’ when it is discovered.”
Whatever the truth of this, Maxwell did enough all those years ago to shake Popper’s resolve. Two weeks after their clash, something completely unheard of happened. A public event was created, and a lecture announced: Popper had authored a response! It was scathing of course, but as Maxwell sat listening to the onslaught, Lakatos leaned over to him in near disbelief and whispered in his ear “this is a great honour to you, Nick.”
It was an indication that Popper took Maxwell seriously. Structured, thought-out criticism takes time – you only do it, if you first consider it important or worthwhile. It is a sign of intellectual respect. And it was also reciprocal: in his early days as a student, first touching on the world of academic philosophy, a younger Maxwell remembers sitting alone in his tiny apartment reading The Open Society And Its Enemies, and crying a flood of tears. At last there was a philosopher who was “actually doing something”, someone who revolutionised epistemology and what it means to be rational, but also someone who extended that logic into other fields.
Through all of this, despite contradicting the older philosopher, Maxwell still considers his work to be highly Popperian. Particularly considering the tradition of criticism that Popper glorified so much. Maxwell’s only gripe is that “I think he should follow suit. If there is an argument that shows that scientific practice straightforwardly refutes his methodology it is something that he should take seriously and not try to push aside with bluster, which is in effect what he does”.
It leads Maxwell to speculate – slightly tongue-in-cheek – that by being so hostile to, and dealing so poorly with, personal criticism, Popper might also, rightly, be considered as an enemy of the Open Society.
Appropriately the whole affair ends on a personal note: “Popper never really liked me…”
*** The Popperian Podcast #3 – Nicholas Maxwell – ‘More Popperian than Popper’ https://popperian-podcast.libsyn.com/the-popperian-podcast-3-nicholas-maxwell-more-popperian-than-popper-0