Questions tagged [philosophy-of-logic]
Philosophy of logic is a branch of philosophy concerned with investigating the nature, scope and role of logic.
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Phenomenology of abstraction
I'm looking for philosophical articles / books that try to describe the process of human abstraction, and what it actually consists of, from a first person perspective. Examples of the type of ...
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What are some books on the foundations of logic and its philosophy?
I think the title pretty much sums up what I'm looking for, but just to elaborate a bit, I'm looking for something that goes into the philosophical basis for logic. Something that investigates the ...
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What is the notion of a proof of a proposition for Martin-Löf?
The notion of proof of a proposition is of the most fundamental notions in Martin-Löf's work on philosophical logic, since it is conceptually prior to the notion of truth - cf "Truth of a proposition, ...
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Is there a logic of married bachelors?
I'm sure this question must have a simple clarification, but I am largely unfamiliar with the branches of formal logic and not sure where to look for it.
We know that "All bachelors are unmarried men"...
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The Logic Of Sense
Can someone help me understand the 11th and 13th series of Delueze's "The Logic Of Sense"
I am struggling to fully understand what he is trying to get across with the ideas of:
nonsense
the ...
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What does Russell mean by "term" in Principles of Mathematics?
Bertrand Russell in Principles of Mathematics defines a term as "Whatever may be an object of thought, or may occur in any true or false proposition or can be counted as one." Can someone elaborate on ...
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Wittgenstein criticizes Coffey's work 'The Science of Logic' in its assumption that every proposition requires a subject and a predicate. Why?
Why does Wittgenstein believe there can be propositions that lack a subject or predicate? What examples does Wittgenstein give in support of this belief?
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What is the most famous book on philosophical logic?
I'm interested in philosophical logic and finding references. I know that there are plenty of reference request of philosophical logic. But it seems to me that most of them are about symbolic logic, ...
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Introductory book on philosophy of logic?
I know that there are quite a few questions like this here already, but I haven't yet found an answer that would satisfy me.
I'm looking for an introductory logic book. My main goal is to work ...
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Exactly what was Wittgenstein's argument against identity?
Roughly Speaking: to say of two things that they are identical is nonsense, and to say of one thing that it is identical with itself is to say nothing. (Tractatus, 5.5302 and 5.5303)
Like Russell ...
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What are Nietzsche's views on truth and logic - for real this time
I'm trying to make sense of Beyond Good and Evil and Nietzsche's views at that time.
The claims he makes about truth and logic seem problematic to me:
"Granted, we will truth: why not untruth ...
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How do we know our logic is correct? [duplicate]
How do we know the logic we use to logically infer is correct? What makes it correct? Why is
"If X exists, then Y exists.
X exists.
Therefore Y exists."
true?
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Proof that deduction is valid in all possible realities?
I was wondering, how can we know that deduction is a valid way to argue for something in all possible realities? How do we know that, in some alternative universe, something is not both ~P and P? How ...
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Are there any strong reasons to still consider logical monism or a "One True Logic" in light of all the non-classical logics that have been developed?
I know there has always been some debate concerning whether or not a certain logical system (like classical logic) is the correct one, especially when it comes to propositional claims about the ...
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Looking for references for some remark of Quine's
I'm looking for a comment I think I remember Quine having made. He's talking about our understanding of proofs. I think he says something along the following lines...
If you understand many different ...
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How can the objects in an object theory be defined?
How can the objects in all object theories be defined?
Do meta-theories refer to things which aren't objects (so defined)?
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What are the propositions?
I've asked before as to what propositions count as meaningful, and, as some commentators and responders helpfully pointed out, 'meaning' and 'propositions' appear to be identical entities in the ...
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Conditional Proof that uses the basic 9 inferences. Can you Please help [closed]
Conditional Proof that uses the basic 9 inferences. I know assumption and indentation is required. Can you Please help
~P
(S>Q) /(PvS)>Q
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A proposition is non-falsifiable. So what?
Does Karl Popper argue that non-falsifiable theories are not true/have no truth value, or simply that they are not provable? Put another way: according to Popper, could a non-falsifiable theory ...
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Logic and presentation
In this question I suggested that logic is almost only ever used in philosophy as a means to present an argument. By implication, I meant that every formal argument can be stated informally, and that ...
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What is the difference between Aristotle's theory of categories and Russell's theory of types?
A partial answer might come through an introduction. Well, we know that Russell's efforts to understand the contradictory appearance of the class of all classes not members of themselves (a notion ...
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Dual of identity relation?
Does anyone have any intuitions about what the dual of the identity relation might be? I.e. is there a 'natural' concept expressed by a statement such as 'it is not the case that a is not identical to ...
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Does a statement exist which is its own proof?
In fake/pseudo mathematical notation: does there exist a statement S such that S = Proof(S)?
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How to start studying philosophical logic?
As I am planing to study philosophical logic, I have some important questions. For example, I wonder:
1 Should I start with the algebraic approach? Should I start with another approach? (Which one?)
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Is there a school of informal logic that treats it as determining how to transcribe arguments into formal logic?
I've noticed it is often nontrivial to transcribe informal arguments into formal logic, but most introductory texts on formal logic make a show of it. Is this for pedagogical reasons only, or is there ...
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Can political ideologies be logically undecidable? If so, what are the consequences of this?
I'm having a thought that I would like more expert opinion on, as this crosses boundaries between philosophical logic and political science.
My premise is that a political ideology can be represented ...
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Why isn't Cantor's diagonal argument just a paradox?
Cantor's diagonal argument concludes the cardinality of the power set of a countably infinite set is greater than that of the countably infinite set.
In other words, the infiniteness of real numbers ...
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Is there any reason for the heavy focus on binary relations in formal logic?
As a fan of C. S. Peirce, I'm surprised that, at least triadic relations, aren't investigated as much as binary relations are. What I mean is that with binary relations, they have already been ...
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What exactly is informal logic and is this what I'm looking for?
I've been reading and researching about formal and symbolic logic for some time now, mainly out of interest in rationality. But I've come to a point where the various logical systems seem more like ...
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The Truth-Falsehood Dichotomy and Logic
Some philosophers argue against truth bivalency, and say that not every statement must be true or false, but some statements can be untrue without being false, or truth-ambiguous, or both true and ...
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What is the role of common sense in logic?
In Logic by Wifred Hodges he says
[..] you must rely on your common sense - as always in logical analysis.
So i'm confused (again!). What has common sense to do with logical reasoning? My previous ...
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Why don't we have consensus in more complicated areas of logic?
When I once realised I don't really understand how and why proof by contradiction works, I started reading about it. And apparently I wasn't the only one who felt there's something wrong about it - ...
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Tractatus 3.333 and Russell's paradox
Can anyone explain to a non-logician how Tractatus 3.333 refutes (or fails to refute) Russell's Paradox? Please explain his use of symbols!
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Are there paradoxes involved in allowing for an unrestricted domain in predicate logic?
I've put some thought into this, and just want to make sure I'm on track, or if I need to be corrected. Basically, my answer is this: Yes, you need to always specify a domain when formalizing into ...
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A Question Regarding Russell's Paradox
Consider the 'set' behind Russell's Paradox:
R = { x | x is a set and x ∉ x }
in light of Cantor's definition of set ("aggregate"/Menge) in his CONTRIBUTIONS TO ...
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Can knowledge about argumentation be sufficient for philosophical logic without too symbolic or mathematical concepts?
The most important element for expression of truth is trough an argument, with premises and conclusion. Argumentation requires to avoid fallacies and adhere to the truth. However logic if treated as a ...
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What is the difference between Law of Excluded Middle and Principle of Bivalence?
Law of Excluded Middle:
In logic, the law of excluded middle (or the principle of excluded
middle) is the third of the so-called three classic laws of thought.
It states that for any proposition, ...
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