Questions related to the work of Kurt Gödel. Please mind the spelling of his last name: "Gödel". If you cannot or don't know how to create the "ö", you might also write his name as "Goedel". In all cases, please avoid "Godel". If you want to create a (hyper)link to, say, a Wikipedia entry, you might ...

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Was Wittgenstein foreshadowing Godel?

The Tractatus 6.123: 6.123 Clearly the laws of logic cannot in their turn be subject to laws of logic. (There is not, as Russell thought, a special law of contradiction for each 'type'; one law ...
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Are there any work around after Godel's incompleteness theorems?

It seems to me that mathematicians or computer science theorists are still trying to come up a proof for conjecture they made in first or second order logic. By Godel's incompleteness theorems there ...
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How did the logical positivists respond to Gödel's incompleteness theorem?

In a lecture on philosophy of science I recently listened to, it was stated that Quine was the one who decisively refuted the logical positivist program. I've also read that Quine and Popper were ...
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80 views

Is this enough to conclude that G is false?

Let us assume a logical system with only 3 axioms (laws of thought): Axiom 1: A statement that is true will remain true till a change is made in the system. Axiom 2: A statement may not be true and ...
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How does Goedel's theorem apply to daily life?

I came across a simplified description of Goedel's theorem and the discussion touches on a concept of honesty (truth?) and completeness. How does Godel's theorem apply to everyday interactions?
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About Godel and Anselm

Was Godel's work on trying to make Anselm's Ontological Argument more 'feasible' with modal logic successful or has this work just been lost in the many abstract debates that confuse the issues?
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Regarding Godel's theorems

Given a formal logic system W with it's set of axioms, if it is capable of 'handling' basic arithmetic then W can not be used to 'prove' its own consistency. In other words there will always be a ...
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2answers
126 views

Provable and contradictory?

For each consistent formal theory T having the required small amount of number theory, the corresponding Gödel sentence G asserts: "G cannot be proved within the theory T". This interpretation of G ...
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1answer
427 views

Does Gödel's second incompleteness theorem interact with logical positivism?

Gödel's second incompleteness theorem (GSIT), informally stated, says: For any formal effectively generated theory T including basic arithmetical truths and also certain truths about formal ...
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295 views

Gödel's ontological proof and the incompleteness theorem

In Gödel's ontological proof, he concludes: "necessarily, God exists" (Theorem 4) Does Gödel's second incompleteness theorem apply to this proof?
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1answer
65 views

Does the finitary proof of the consistency of relevant PA shows that first order PA is irrelevant?

Relevance logic takes a closer look at the implication operation in first-order logic. It suggests that implications such as: p and not p -> q cannot hold; in ordinary English, an example of ...
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2answers
156 views

Can we expand the notion of truth in Godels incompleteness theorem?

Godels incompleteness theorem, which really should be called the undecidability theorem given that the paper of Godels which this theorem is taken from is named 'On formally undecidable propositions ...
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3answers
226 views

What is the connection between provability logic & Gödel's first incompleteness theorem?

Provability logic is a modal logic that interprets the modal operator of K as provability and an additional axiom derived from Löb's theorem. Now the SEP shows that it's possible to derive Gödel's ...
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1answer
125 views

Is there a finitistic set theory, and if there is, is it provably consistent?

ZFC is the mainstream set theory. It has an axiom of infinity which claims that there is at least one infinite set. Now suppose like Aristotle, we object and say that there are no actually infinites ...
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1answer
268 views

What is the impact of paraconsistency on Gödel's theorem?

Russell's paradox forced a restriction of the natural abstraction principle (that every predicate determines a set) so that set theory could be consistent; the standard one being ZF. However ...
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2answers
268 views

Is Gödel's incompleteness theorem still valid if one uses a higher-order logic?

Gödel's incompleteness theorem is wholly formal (in my understanding), and relies on a proof system that I assume is first-order. Does it make any difference to the theorem if higher-order logic is ...
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1answer
199 views

In Gödels Incompleteness theorem what is the notion of truth?

The entry on Gödels Incompletenss theorem in Wikipedia says: Any effectively generated theory capable of expressing elementary arithmetic cannot be both consistent and complete. In particular, for ...
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1answer
165 views

What happens when we drop the condition that proofs are finite strings of inferences in Gödel's incompleteness theorem?

Gödel's incompleteness theorem shows that there are sentences that are undecideable, that is they nor their negation can be proved. This theorem operates purely syntactically or formally, that it ...
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3answers
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How is Gödel's incompleteness theorem interpreted in intuitionistic logic?

Classically, one sets up an axiomatic system with a formal deduction system & an interpretation in a model. Generally it is sound, that is: a formally deduced theorem is also true when interpreted ...
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3answers
124 views

Can we add to PA a new predicate T such that for every sentence A of the old vocabulary the new theory proves T(Godel numeric number of A) iff A

I am new to logic but I believe this is not a difficult problem, yet I am still soo confused, and the reason for that is because there are so many gaps in my knowledge or maybe I have overlooked so ...
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2answers
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Goedel's theorem and God

I have seen it argued that Goedel's Incompleteness Theorems have implications to existence of God. Arguments for existence of God run mostly along the lines: "Because of Goedel's Theorem, truth ...
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3answers
208 views

Was Gödel the first person to bring up that truth always exceeds the grasp of proof?

Was Gödel the first person to pose and solve this question in mathematics? In the larger philosophical debate, has this question been posed before? Say by Plato or Aristotle? One could interpret for ...
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6answers
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What's the big deal with Gödel's second incompleteness theorem?

Edit: My question is specifically about Gödel's second incompleteness theorem. I get the significance of his first incompleteness theorem, which is of course completely amazing. According to the ...
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2answers
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Relation of Gödel's incompleteness theorems and Karl Popper falsification

Falsifiability is considered a positive (and often essential) quality of a hypothesis because it means that the hypothesis is testable by empirical experiment and thus conforms to the standards ...
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2answers
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Did Russell understand Gödel's incompleteness theorems?

Russell was active in philosophy (although no longer in math) for many years after the Gödel's 1931 publication. Gödel's paper were not obscure, and Russell would have been aware of their effect on ...
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5answers
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What are the philosophical implications of the Halting Problem?

In a great answer, a community member gave the following proof sketch that the halting problem is undecidable: Proof that the halting problem is undecidable. If there were a computable procedure ...
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3answers
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Do Gödel's incompleteness theorems support the idea that the examination of a 'system' should only be undertaken to arrive at the inconsistency?

Roughly, Gödel demonstrated that in a logical system, that contains a model or arithmetic, there are statements which may be true, but are unprovable within the system. If a statement is not ...
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1answer
903 views

When it is correct to use Tarski's undefinability theorem versus Gödel's incompleteness theorem?

Smullyan (1991, 2001) has argued forcefully that Tarski's undefinability theorem deserves much of the attention garnered by Gödel's incompleteness theorems. That the latter theorems have much to ...
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4answers
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What are the philosophical implications of Gödel's First Incompleteness Theorem?

Gödel's First Incompleteness Theorem states Any effectively generated theory capable of expressing elementary arithmetic cannot be both consistent and complete. In particular, for any ...
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Is Kurt Gödel's Incompleteness Theorem a “cheap trick”?

I found a throw-away critique of Kurt Gödel's Incompleteness Theorem in an essay about Deconstruction: The basic enterprise of contemporary literary criticism is actually quite simple. It is based ...