Godel and Wittgenstein; same goal, different approach

 The current issue of Philosophy Now (Issue 169, Aug/Sep 2025) has as its theme, The Sources of Knowledge Issue, with a clever graphic on the cover depicting bottles of ‘sauces’ of 4 famous philosophers in this area: Thomas Kuhn, Karl Popper, Kurt Godel and Edmund Gettier. The last one is possibly not as famous as the other 3, and I’m surprised they didn’t include Ludwig Wittgenstein, though there is at least one article featuring him inside.
 
I’ve already written a letter to the Editor over one article Challenging the Objectivity of Science by Sina Mirzaye Shirkoohi, who is a ‘PhD Candidate at the Faculty of Administrative Sciences of the University Laval in Quebec City’; and which I may feature in a future post if it gets published.
 
But this post is based on an article titled Godel, Wittgenstein & the Limits of Knowledge by Michael D McGranahan, who has a ‘BS in Geology from San Diego State and an MS in Geophysics from Stanford, with 10 years [experience] in oil and gas exploration before making a career change’, without specifying what that career change is. ‘He is a lifelong student of science, philosophy and history.’ So, on the face of it, we may have a bit in common, because I’ve also worked in oil and gas, though in a non-technical role and I have no qualifications in anything. I’ve also had a lifelong interest in science and more recently, philosophy, but I’m unsure I would call myself a student, except of the autodidactic kind, and certainly not of history. I’m probably best described as a dilettante.
 
That’s a long runup, but I like to give people their due credentials, especially when I have them at hand. McGranahan, in his own words, ‘wants to explore the convergence of Godel and Wittgenstein on the limits of knowledge’, whereas I prefer to point out the distinctions. I should say up front that I’m hardly a scholar on Wittgenstein, though I feel I’m familiar enough with his seminal ideas regarding the role of language in epistemology. It should also be pointed out that Wittgenstein was one of the most influential philosophers of the 20th Century, especially in academia.
 
I will start with a quote cited by McGranahan: “The limits of my language mean the limits of my world.”
 
I once wrote a rather pretentious list titled, My philosophy in 24 dot points, where I paraphrase Wittgenstein: We think and conceptualise in a language. Axiomatically, this limits what we can conceive and think about. This is not exactly the same as the quote given above, and it has a subtly different emphasis. In effect, I think Wittgenstein has it back-to-front, based solely on his statement, obviously out-of-context, so I might be misrepresenting him, but I think it’s the limits of our knowledge of the world, that determines the limits of our language, rather than the other way round.
 
As I pointed out in my last post, we are continually creating new language to assimilate new knowledge. So, when I say, ‘this limits what we can conceive and think about’, it’s obvious that different cultures living in different environments will develop concepts that aren’t necessarily compatible with each other and this will be reflected in their respective languages. It’s one of the reasons all languages adopt new words from other languages when people from different cultures interact.
 
Humans are unique in that we think in a language. In fact, it’s not too much of a stretch to analogise it with software, remembering software is a concept that didn’t come into common parlance until after Wittgenstein died in 1951 (though Turing died in 1954).
 
To extend that metaphor, language becomes our ‘operating language’ for ‘thinking’, and note that it happens early in one’s childhood, well before we develop an ability to comprehend complex and abstract concepts. Just on that, arguably our exposure to stories is our first encounter with abstract concepts, if by abstract we mean entities that only exist in one’s mind.
 
I have a particular view, that as far as I know, is not shared with anyone else, which is that we have a unique ability to nest concepts within concepts ad infinitum, which allows us to create mental ‘black boxes’ in our thinking. To give an example, all the sentences I’m currently writing are made of distinct words, yet each sentence has a meaning that transcends the meaning of the individual words. Then, of course, the accumulation of sentences hopefully provides a cogent argument that you can follow. The same happens in a story which is arguably even more amazing, given a novel (like Elvene) contains close to 100k words, and will take up 8hrs of your life, but probably over 2 or 3 days. So we maintain mental continuity despite breaks and interruptions.
 
Wittgenstein once made the same point (regarding words and sentences), so that specific example is not original. Where my view differs is that I contend it also reflects our understanding of the physical world, which comprises entities within entities that have different physical representations at different levels. The example I like to give is a human body made up of individual cells, which themselves contain strands of DNA that provide the code for the construction and functioning of an individual. From memory, Douglas Hoffstadter made a similar point in Godel Escher Bach, so maybe not an original idea after all.
 
Time to talk about Godel. I’m not a logician, but I don’t believe you need to be to appreciate the far-reaching consequences of his groundbreaking theorem. In fact, as McGranahan points out, there are 2 theorems: Godel’s First Incompleteness Theorem and his Second Incompleteness Theorem. And it’s best to quote McGranahan directly:
 
Godel’s First Incompleteness Theorem proves mathematically that any consistent formal mathematical system within which a certain amount of elementary arithmetic can be carried out, is incomplete – meaning, there are one or more true statements that can be made in the language of the system which can neither be proved nor disproved in the system.
 
He then states the logical conclusion of this proof:
 
This finding leads to two alternatives: Alternative #1: If a set of axioms is consistent, then it is incomplete. Alternative #2: In a consistent system, not every statement can be proved in the language of that system.
 
Godel’s Second Incompleteness Theorem is simply this: No set of axioms can prove its own consistency.
 
It’s Alternative #2 that goes to the nub of the theorem: there are and always will be mathematical ‘truths’ that can’t be proved ‘true’ using the axioms of that system. Godel said himself that such truths (true statements) might be proved by expanding the system with new axioms. In other words, you may need to discover new mathematics to uncover new proofs, and this is what we’ve found in practice, and why some conjectures take so long to prove – like hundreds of years. The implication behind this is that our search for mathematical truths is neverending, meaning that mathematics is a neverending endeavour.
 
As McGranahan succinctly puts it: So knowing something is true, and proving it, are two different things.
 
This has led Roger Penrose to argue that Godel’s Theorems demonstrate the distinction between the human mind and a computer. Because a human mind can intuit a ‘truth’ that a computer can’t prove with logic. In a sense, he’s right, which is why we have conjectures like the ones I mentioned in my last post relating to prime numbers – the twin prime conjecture, the Goldbach conjecture and Riemann’s famous hypothesis. However, they also demonstrate the relationship between Godel’s Theorem and Turing’s famous Halting Problem, which Gregory Chaitin argues are really 2 manifestations of the same problem.
 
With each of those conjectures, you can create an algorithm to find all the solutions on a computer, but you can’t run the computer to infinity, so unless it ‘stops’, you don’t know if they’re true or not. The irony is that (for each conjecture): if it stops, it’s false and if it’s true, it never stops so it’s unknown. I covered this in another post where I argued that there is a relationship between infinity and the unknowable. The obvious connection here, that no one remarks on, is that Godel’s theorems only work because mathematics is infinite. If it was finite, it would be 'complete'. I came to an understanding of Godel’s Theorem through Turing’s Halting Problem, because it was easier to understand. A machine is unable to determine if a mathematical ‘truth’ is true or not through logic alone.
 
According to McGranahan, Wittgenstein said that “Tautology and contradiction are without sense.” He then said, “Tautology and contradiction are, however, nonsensical.” This implies that ‘without sense’ and ‘nonsensical’ have different meanings, “which illustrates the very language problem of which we speak” (McGranahan using Wittgenstein’s own language style to make his point). According to McGranahan, Wittgenstein then concluded: “that mathematics (if tautology and contradiction will be allowed to stand for mathematics), is nonsense.” (Parentheses in the original)
 
According to McGranahan, “…because in his logic, mathematical formulae are not bipolar (true or false) and hence cannot form pictures and elements and objects [which is how Wittgenstein defines language], and thus cannot describe actual states of affairs, and therefore, cannot describe the world.”
 
I feel that McGranahan doesn’t really resolve this, except to say: “There would seem to be a conflict… Who is right?” I actually think that if anyone is wrong, it’s Wittgenstein, though I admit a personal prejudice, in as much as I don’t think language defines the world.
 
On the other hand, everything we’ve learned about the world since the scientific revolution has come to us through mathematics, not language, and that was just as true in Wittgenstein’s time as it is now; after all, he lived through the 2 great scientific revolutions of quantum mechanics and relativity theory, both dependent on mathematics only discovered after Newton’s revolution.
 
The limits of our knowledge of the physical world are determined by the limits of our knowledge of mathematics (known as physics). And our language, while it ‘axiomatically limits what we can conceive and think about’, can also be (and continually is) expanded to adopt new concepts.

Reality, metaphysics, infinity

 This post arose from 3 articles I read in as many days: 2 on the same specific topic; and 1 on an apparently unrelated topic. I’ll start with the last one first.
 
I’m a regular reader of Raymond Tallis’s column in Philosophy Now, called Tallis in Wonderland, and I even had correspondence with him on one occasion, where he was very generous and friendly, despite disagreements. In the latest issue of Philosophy Now (No 169, Aug/Sep 2025), the title of his 2-page essay is Pharmaco-Metaphysics? Under which it’s stated that he ‘argues against acidic assertions, and doubts DMT assertions.’ Regarding the last point, it should be pointed out that Tallis’s background is in neuroscience.
 
By way of introduction, he points out that he’s never had firsthand experience of psychedelic drugs, but admits to his drug-of-choice being Pino Grigio. He references a quote by William Blake in The Marriage of Heaven and Hell: “If the doors of perception were cleaned, then everything would appear to man as it is, Infinite.” I include this reference, albeit out-of-context, because it has an indirect connection to the other topic I alluded to earlier.
 
Just on the subject of drugs creating alternate realities, which Tallis goes into in more detail than I want to discuss here, he makes the point that the participant knows that there is a reality from which they’ve become adrift; as if they’re in a boat that has slipped its moorings, which has neither a rudder nor oars (my analogy, not Tallis’s). I immediately thought that this is exactly what happens when I dream, which is literally every night, and usually multiple times.
 
Tallis is very good at skewering arguments by extremely bright people by making a direct reference to an ordinary everyday activity that they, and the rest of us, would partake in. I will illustrate with examples, starting with the psychedelic ‘trip’ apparently creating a reality that is more ‘real’ than the one inhabited without the drug.
 
The trip takes place in an unchanged reality. Moreover, the drug has been synthesised, tested, quality-controlled, packaged, and transported in that world, and the facts about its properties have been discovered and broadcast by individuals in the grip of everyday life. It is ordinary people usually in ordinary states of mind in the ordinary world who experiment with the psychedelics that target 5HT2A receptors.
 
He's pointing out an inherent inconsistency, if not outright contradiction (contradictoriness is the term he uses), that the production and delivery of the drug takes place in a world that the recipient’s mind wants to escape from.
 
And the point relevant to the topic of this essay: It does not seem justified, therefore, to blithely regard mind-altering drugs as opening metaphysical peepholes on to fundamental reality; as heuristic devices enabling us to discover the true nature of the world. (my emphasis)
 
To give another example of philosophical contradictoriness (I’m starting to like this term), he references Berkeley:
 
Think, for instance of those who, holding a seemingly solid copy of A Treatise Concerning the Principle of Human Knowledge (1710), accept George Berkeley’s claim [made in the book] that entities exist only insofar as they are perceived. They nevertheless expect the book to be still there when they enter a room where it is stored.
 
This, of course, is similar to Donald Hoffman’s thesis, but that’s too much of a detour.
 
My favourite example that he gives, is based on a problem that I’ve had with Kant ever since I first encountered Kant.
 
[To hold] Immanuel Kant’s view that ‘material objects’ located in space and time in the way we perceive them to be, are in fact constructs of the mind – then travel by train to give a lecture on this topic at an agreed place and time. Or yet others who (to take a well-worn example) deny the reality of time, but are still confident that they had their breakfast before their lunch.
 
He then makes a point I’ve made myself, albeit in a different context.
 
More importantly, could you co-habit in the transformed reality with those to whom you are closest – those who accept without question as central to your everyday life, and who return the compliment of taking you for granted?
 
To me, all these examples differentiate a dreaming state from our real-life state, and his last point is the criterion I’ve always given that determines the difference. Even though we often meet people in our dreams with whom we have close relationships, those encounters are never shared.
 
Tallis makes a similar point:
 
Radically revisionary views, if they are to be embraced sincerely, have to be shared with others in something that goes deeper than a report from (someone else’s) experience or a philosophical text.
 
This is why I claim that God can only ever be a subjective experience that can’t be shared, because it too fits into this category.
 
I recently got involved in a discussion on Facebook in a philosophical group, about Wittgenstein’s claim that language determines the limits of what we can know, which I argue is back-to-front. We are forever creating new language for new experiences and discoveries, which is why experts develop their own lexicons, not because they want to isolate other people (though some may), but because they deal with subject-matter the rest of us don’t encounter.
 
I still haven’t mentioned the other 2 articles I read – one in New Scientist and one in Scientific American – and they both deal with infinity. Specifically, they deal with a ‘movement’ (for want of a better term) within the mathematical community to effectively get rid of infinity. I’ve discussed this before with specific reference to UNSW mathematician, Norman Wildberger. Wildberger recently gained attention by making an important breakthrough (jointly with Dean Rubine using Catalan numbers). However, for reasons given below, I have issues with his position on infinity.
 
The thing is that infinity doesn’t exist in the physical world, or if it does, it’s impossible for us to observe, virtually by definition. However, in mathematics, I’d contend that it’s impossible to avoid. Primes are called the atoms of arithmetic, and going back to Euclid (325-265BC), he proved that there are an infinite number of primes. The thing is that there are 3 outstanding conjectures involving primes: the Goldbach conjecture; the twin prime conjecture; and the Riemann Hypothesis (which is the most famous unsolved problem in mathematics at the time of writing). And they all involve infinities. If infinities are no longer ‘allowed’, does that mean that all these conjectures are ‘solved’ or does it mean, they will ‘never be solved’?
                                                                                                                    
One of the contentions raised (including by Wildberger) is that infinity has no place in computations – specifically, computations by computers. Wildberger effectively argues that mathematics that can’t be computed is not mathematics (which rules out a lot of mathematics). On the other hand, you have Gregory Chaitin who points out that there are infinitely more incomputable Real numbers than computable Real numbers. I would have thought that this had been settled, since Cantor discovered that you can have countable infinite numbers and uncountable infinite numbers; the latter being infinitely larger than the former.
 
Just today I watched a video by Curt Jaimungal interviewing Chiara Marletto on ‘Constructor Theory’, which to my limited understanding based on this extract from a larger conversation, seems to be premised on the idea that everything in the Universe can be understood if it’s run on a quantum computer. As far as I can tell, she’s not saying it is a computer simulation, but she seems to emulate Stephen Wolfram’s philosophical position that it’s ‘computation all the way down’. Both of these people know a great deal more than me, but I wonder how they deal with chaos theory, which seems to drive the entire universe at multiple levels and can’t be computed due to a dependency on infinitesimal initial conditions. It’s why the weather can’t be forecast accurately beyond 10 days (because it can’t be calculated, no matter how complex the computer modelling) and why every coin-toss is independent of its predecessor (unless you rig it).
 
Note the use of the word, ‘infinitesimal’. I argue that chaos theory is the one phenomenon where infinity meets the real world. I agree with John Polkinghorne that it allows the perfect mechanism for God to intervene in the physical world, even though I don’t believe in an interventionist God (refer Marcus du Sautoy, What We Cannot Know).
 
I think the desire to get rid of infinity is rooted in an unstated philosophical position that the only things that can exist are the things we can know. This doesn’t mean that we currently know everything – I don’t think any mathematician or physicist believes that – but that everything is potentially knowable. I have long disagreed. And this is arguably the distinction between physics and metaphysics. I will take the definition attributed to Plato: ‘That which holds that what exists lies beyond experience.’ In modern science, if not modern philosophy, there is a tendency to discount metaphysics, because, by definition, it exists beyond what we experience in the real world. You can see an allusion here to my earlier discussion on Tallis’s essay, where he juxtaposes reality as we experience it with psychedelic experiences that purportedly provide a window into an alternate reality, where ‘everything would appear to man as it is, Infinite’. Where infinity represents everything we can’t know in the world we inhabit.
 
The thing is that I see mathematics as the only evidence of metaphysics; the only connection our minds have between a metaphysical world that transcends the Universe, and the physical universe we inhabit and share with innumerable other sentient creatures, albeit on a grain of sand on an endless beach, the horizon of which we’re yet to discern.
 
So I see this transcendental, metaphysical world of endless possible dimensions as the perfect home for infinity. And without mathematics, we would have no evidence, let alone a proof, that infinity even exists.