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Gottlob Frege: The machine in the ghost (2017) (prospectmagazine.co.uk)
30 points by cacher on Sept 30, 2022 | hide | past | favorite | 24 comments



How completely obnoxious article. Frege was a tragic figure in philosophy, his work was recognized only through Russel and he is still very much ignored by the tradition he created. He answered the Russel paradox in the same way modern theory does, by introducing types, but instead of learning from him, especially the epistemological parts that are a relevant connection of analytical philosophy to kantianism, he was ignored and is for some reason ridiculed by the anglosphere tradition that know him only through Russel (the most overrated philosopher in history).


Frege is all over analaytic philosophy, as I experienced it as an undergraduate in a top department. Many of the most important papers and books (Dummett, Kripke, Evans, etc) in philosophy of language, logic, mathematics take various of his positions as starting points.

I would describe Frege as the philosopher I had never heard of before showing up at a philosophy department whom I then heard the most about.

His insights were "forgotten" for a time, but have been central to discussions for several decades.


As others have said, I do think Frege gets a fair shake in academia, but he definitely could be studied more. He certainly doesn’t have the near pop-philosophical status of a Russel. I would also agree that Russel is overrated. For some reason, the public seems to love experts of narrow technical or scientific fields that proffer, usually inadequate, takes of other areas like morals all whilst ignoring the experts in fields like morality (I can think of some other situations in which the political opinions of e.g. cosmologists are venerated on the basis of their expertise in cosmology, which of course makes absolutely no sense but seems to be something people love to do. Apparently deeply specialized expertise means you’re “smart” and therefore anything you say even on subjects you don’t know a lick about must also be “smart”)

Aside from Wittgenstein, Frege is the “analytic” philosopher I most admire. There’s a certain creative genius that shines through his work that I feel is absent from the work of many other analytic philosophers. His short Foundations of Mathematics text quite literally changed my life by making math interesting to me for the first time. I was lucky enough to read a copy of the Begriffs chrift since my school’s library had it, it’s a work of beauty!


There's too much focus on Frege (as well as Russell and Wittgenstein) in analytic philosophy.

You would think people such as Boole, Peirce, Łukaiewicz, Tarski, Brouwer, Heyting, Gentzen, Prawitz, Girard, and Martin-Löf are mere footnotes in the history of logic. Yet their work is more relevant and used by working mathematicians and computer scientists.


This is a brilliant comment. Thank you.

Each in turn:

Boole invented propositional logic. Peirce supposedly invented a lot, but got overlooked. Łukaiewicz, I'm not sure. Tarski employed quantifier elimination to prove the decidability of various theories like Euclidean geometry. Brouwer invented intuitionistic logic, and a(n arguably) viable approach to doing analysis and topology intuitionistically. Heyting provided semantics to intuitionistic logic. Gentzen created the proof calculus Natural Deduction which resembles informal proofs (as well as the closely related proof calculus Sequent Calculus). Prawitz I don't know. Girard, I don't know. Martin-Löf derived Dependently Typed Lambda Calculus using the Curry-Howard correspondence.

I guess all this stuff gets overlooked because Russell's goal was very ambitious: He wanted to connect formal logic with everyday language, and how to perform sound everyday reasoning. In that sense, his ambition was similar to the Stoics. The above stuff mostly doesn't address this use-case.


The people I mentioned and their work are intentionally overlooked because it doesn't fit a dogma around Platonic Realism and Classical Logic.


And Gödel, of course.


I'm not sure that Russell is overrated by non-philosophers - his unusual popular fame for his field is down to his brilliance as a writer and communicator, and charisma and social engagement as a human being. Those are valuable qualities and he is rated accordingly for them.


I'm inclined to agree that Russell was overrated. His most influential work was a mistake.

> he is still very much ignored by the tradition he created

Really? When I studied philosophy[0], reading at least some Frege was required for Philosophy of Logic and Philosophy of Language. Frege wasn't treated as obscure or unimportant; quite the reverse. Have things changed?

[0] University of London, early 80's. Philosophical tastes vary rather widely from one institution to another.


> His most influential work was a mistake.

Why? I think you're referring to Principia, which is a predecessor to Coq and Lean. While Coq and Lean don't use Principia's formalism, they do try and tackle the same problem. What did Principia fail at?

[edit]

Or are you referring to the programme of using formal logic to understand language and reliable everyday reasoning?


Principia was destroyed by Gödel, within about two years of its publication. That's what I'm referring to.


No, it wasn't. I'm sometimes not sure if philosophers understand Goedel's incompleteness theorem. What do you base your claim on?

GIT is more a statement about the limitations of the proof-driven approach to mathematics than it is about any formalisation of mathematics like Principia's. It shows that whatever assumptions proofs are based on cannot be shown consistent except by assuming something even stronger. Principia is affected to exactly the same degree as all proof-driven mathematics, and no more.

I'm not sure whether there has ever been a satisfactory answer to the 2nd GIT among the mathematical establishment. I guess mathematicians just assume that everything is consistent, and go about proving theorems as normal. It seems that almost no mathematician understands - let alone cares about - these foundational concerns.

Principia is the predecessor to modern software like Lean, Coq and Agda. Nothing got destroyed.


> I'm sometimes not sure if philosophers understand Goedel's incompleteness theorem

I'm usually not sure if I understand it (reverse: Im usually sure that I don't understand it). Also: I'm not a philosopher - I'm an old man that did a philosophy BA 40 years ago. I can't unpack this stuff.

I see a consonance between Gödel's theorems, Heisenberg's principle, Turing's work on computability, and some of the stuff in Frege and Wittgenstein. Maybe even Cantor. I wish I could to say this clearly-enough for someone to knock down. But I can't do the maths; I'm entirely dependent on the explanations of others.


[I wrote this yesterday, but didn't post it]

Let's assume that mathematics is a job that follows the following rules: You use two languages: Predicate Logic and Natural Deduction. You use Predicate Logic to write claims like "There are infinitely many prime numbers", and you use Natural Deduction to construct proofs of such claims. Both languages are formal. And you can even use a computer to verify that you're using them correctly.

To prove things, you need to assume that some things are true. These "assumptions" are called axioms, and are expressed using Predicate Logic. Philosophically speaking, the rules of Natural Deduction can be thought of as axioms for how to correctly construct proofs, but they're usually called "inference rules" and not axioms for minor technical reasons.

The methodology which we described arises inevitably from a proof-driven approach to mathematics, because mathematicians need a way to agree which methods of argumentation they think are correct, and also to prevent people from making things up. Admittedly, this is only true for those mathematicians who have looked into these foundational matters.

Some axioms can lead to an accident where you can prove a proposition and its negation simultaneously. (An example in set-theoretic foundations is Unrestricted Comprehension.) By a simple result called the principle of explosion, in such a situation you can prove every proposition and its negation. So such axiom sets are useless. We call them inconsistent.

A question arises: Given a set of axioms which is sufficient to serve as a foundation of mathematics - like ZFC set theory for instance, or less obviously Peano arithmetic - is it possible to construct a proof of their own consistency from those same axioms alone? The answer is no, and this is Goedel's 2nd Incompleteness Theorem.

You can - in a way - prove that Peano arithmetic (for instance) is consistent, but you need to assume axioms which are strictly more powerful than Peano arithmetic. And to show the consistency of those axioms, you need to assume yet stronger ones. This is quite a disturbing situation.

Ultimately, the theorem is a statement about the methodology for doing mathematics which we described. But there is no escaping it if mathematics is about stating claims and proving them.


Thanks - that's a succinct and interesting summary of something; but I'm not sure how it's a reply to my comment :-)


Well, I'm out of my depth. I didn't study Principia or Gödel at school, and I've never really looked into Principia. My understanding is that Principia was an effort to prove that (a) mathematics was logic; and (b) that mathematics was self-consistent. And that Gödel proved that this goal couldn't be achieved.

Is that wrong? If I've got that wrong, I have a big attitude adjustment coming down the track towards me.


I studied philosophy 10 years ago and we did several weeks on Sense and Reference in one of the modules. He also was discussed in other classes in relation to Kripke and other more modern philosophers.


Yeah, he is discussed in seminars as a kind of proto analytical philosopher.


We studied him too, he kicks off most of the major anthologies. Seems he's almost universally considered an overlooked founder of analytic philosophy. (There's the famous story about how Wittgenstein showed up on his doorstep to move in and study and Frege said, "no just go to Russell," he even underrated himself.)

So he is partly famous for not being famous, a paradox he would hopefully appreciate.


I read The Foundations of Arithmetic and On Sense and Reference for my analytic philosophy course. This was in the U.S. fifteen years ago. I agree that he was not treated as obscure at all. We wouldn't have Carnap (the analytic philosopher) without Frege.


I meant analytic philosophy, that hardly ever includes Frege.


Clive James led off an essay by suggesting that there was a buddy movie to be made around Wittgenstein and Russell. He was joking, but part of the joke is that their fame much outran any engagement with or even interest in their philosophical work. I don't think that leaving little memory beyond the work is a bad thing. What does it add to one's understanding of Kant to know a few anecdotes about the regularity of his life.

One can regret the opinions in Frege's diaries without it affecting what one thinks about the work.


> What does it add to one's understanding of Kant to know a few anecdotes about the regularity of his life.

If we can build up a picture of someone from anecdotes about their life we can use this information to inform our understanding of why their work might have taken one form rather than another.

For example, Schopenhauer criticised the notoriously obscure schemata of Kant's Critique of Pure Reason by saying that it was a result of Kant's psychological need for architectonic symmetry.

https://en.wikipedia.org/wiki/Schema_(Kant)#cite_ref-93


That he took a walk everyday is somewhat informative, given how much of his philosophy is centered on normativity, but I prefer the anecdote about how he was a billiards hustler as a student, because even more pointedly, Kant's philosophy is about making space for human freedom in a world of Newtonian mechanical determination.

Great love for Wittgenstein, Russell, Frege, the Vienna Circle—their philosophical and logical writings—and I do feel alienated when I encounter their popular treatments, because it makes my ego feel special having read their most important works, but I bet the Wittgenstein-Russell fame was good for lots of people getting exposed to the path: I heard about them in a Time Magazine special edition retrospective on artists and thinkers of the 20th Century 22 years ago.




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