Questions tagged [logic]
For questions about logic, whether it concerns syllogistic logic, mathematical logic or the nature of logic itself.
403
questions with no upvoted or accepted answers
8
votes
1
answer
228
views
The enunciation clause (Lyotard & Levinas)
As kind of introductory remark, let me state that I'm not academically-trained in philosophy, so my apologies if this comes up as a rather simple question.
I was reading Logique de Levinas by JF ...
- 181
5
votes
2
answers
205
views
What is an explanation really?
Let's consider a hypothetical 'Church of the Moon' on a distant planet with a huge moon. The members of this church base all their beliefs about the moon and their religious practices on their holy ...
user66933
4
votes
2
answers
152
views
Is an argument with contradictory premises valid?
I have hard time determining whether the below argument is valid:
(P1) Nobody ever plays with a bear.
(P2) Bob plays with a bear.
(C) Therefore, bears are friendly.
I think this argument is valid. ...
- 157
4
votes
0
answers
112
views
Philosophical meaning of the Curry Howard Correspondence
At a technical level, I understand the Curry-Howard correspondence in various settings, and its usefulness as a technical tool. What I'm looking for is a fairly rigorous discussion of genuinely ...
- 139
4
votes
0
answers
92
views
What questions or areas in the foundations of mathematics remain active research fields?
By foundations of mathematics I am referring to the mathematical, logical, and philosophical foundations of the subject. I'm interested in seeing which of these have active research going on within ...
4
votes
1
answer
467
views
Is Tarski's derivation of the Liar paradox valid?
First a link to his derivation:
http://www.jfsowa.com/logic/tarski.htm
Its a famous essay so you really should read all of it but at the moment its enough if you read section 7 where Tarski derives ...
- 341
3
votes
0
answers
89
views
Is there a Formal discipline of tying Logic Puzzles to Mathematical Equations?
I am attempting to find the answer to a long standing question in mathematics, known as the Collatz Conjecture.
In this attempt, I’ve figured for myself, in a way that I haven’t seen produced anywhere ...
- 31
3
votes
0
answers
34
views
What are some ways of understanding plural predication (and what are some academic resources on the matter)?
The particular case I'm thinking about has to do with existence. Peter Van Inwagen writes:
'When I say that affirmation of existence is denial of the number zero, I
mean only that to say that Fs exist ...
- 91
3
votes
0
answers
79
views
Entry points from philosophy into mathematics at higher levels?
Everytime I look up of the link between philosophy and mathematics, I see the topics only of the most foundational levels discussed. As in logic, and stuff. When I study higher mathematics theories, ...
- 2,128
3
votes
2
answers
158
views
How does logic deal with objects that change?
Say I have an object that is currently red, but in one day will be painted green. If I put it in my formal language with a constant symbol 's' and define the colours green and red using 'g' and 'r' ...
- 1,073
3
votes
0
answers
67
views
Is the assertion of a moral imperative in complying with a person's self-attested "gender" consistent with broader principles of declared attributes?
The Wikipedia style guide discusses how if a person states that they consider themselves a particular gender, selects a name for themselves in conjunction with a change in gender, and asserts ...
- 116
3
votes
0
answers
107
views
How could second-order logic satisfy (neo) Fregean's epistemic goal?
Recently I've been reading Shapiro's Higher Order Logic in The Oxford Handbook of Philosophy of Mathematics and Logic, Chapter 25. There are some paragraphs confusing me:
One traditional goal of ...
- 31
3
votes
0
answers
112
views
First-order semantics for plural logic
There are commonly thought to be two kinds of set-theoretic semantics for second-order logic: the standard one, where relation (and function) variables range over the entire power set of a model ...
- 292
3
votes
0
answers
68
views
Is there a "for dummies" construction of the valuation model of the relevance logic R from a De Morgan monoid?
I am confused how one gets the anti-chain preserving negation in Belnap-Dunn's FOUR, which by all accounts underlies their R (which adds implication), when R's valuation model is constructed from a De ...
- 1,942
3
votes
1
answer
291
views
What is the meaning of Principle C'' in Hartry Field's 'Science Without Numbers'?
For Field, the following is 'perfectly obvious', but I would like confirmation that I understand it completely.
Let A be a nominalistically statable assertion.
Let A* be the assertion that results by ...
- 61
3
votes
0
answers
77
views
A Paradox for Anti-Realism?
Semantic Anti-Realists hold that a claim has a (constructive) proof if the claim is true. I wonder whether this position runs into a version of Yablo's supposedly non-circular version of the liar ...
- 1,388
3
votes
1
answer
256
views
Rewriting a set of propositions that includes a circular proposition
"For any proposition P, if I believe that P then this paragraph (everything that is written between the quotes) entails that I believe that P.
I believe that I exist.
For any proposition P, if I ...
- 31
3
votes
0
answers
373
views
Grice: Comparing Natural Meaning, Non-Natural Meaning, Conventional Implicature and Generalized Conversational Implicature
I am currently reading "Meaning" and "Logic and Conversation" by Paul Grice.
I find it a little difficult to differentiate clearly between his concepts "natural meaning", "non-natural meaning", "...
- 31
3
votes
0
answers
94
views
Are there degrees of rationality/plausibility to assumptions?
There are many kinds of premises, in every possible field. I'll limit this question to metaphysics, although it can definitely be applied to each and every scientific/philosophical study.
For example,...
- 3,846
3
votes
0
answers
96
views
What to read for an introduction on the epistemology of logic?
I would like to read about the epistemology of logic, preferably at a undergraduate level (not being a philosopher myself). What (text)book should I read for a good introduction on these topics?
The ...
- 113
3
votes
0
answers
91
views
Is a Thomist possible modal proposition a non-judicative proposition?
According to Thomist philosophy and logic, is a possible modal proposition (either divisive or compound) a non-judicative proposition? It would seem to me that the other three modal propositions (...
- 31
3
votes
0
answers
568
views
What are some of the best books for a robust introduction to Logic and Critical Thinking?
As the question states:
What are some of the best books for a robust introduction to Logic and Critical Thinking?
My background:
I'm 24, graduating with two degrees in Political Science and ...
- 31
3
votes
0
answers
179
views
Can Kant's antinomies be translated into formal logic?
Kant proves the limits of human reason by providing 4 antinomies, pairs of rational but contradictory statements, which he claims pure reason can never help us decide which one of the pair is correct. ...
- 27.1k
3
votes
0
answers
118
views
Why can some arguments be proven only through Conditional or Indirect Proof?
For brevity, abbreviate as CP 'Conditional Proof', as DM 'Direct Method, and as IP 'Indirect Proof'.
Source: p 445, A Concise Introduction to Logic (12 Ed, 2014) by Patrick Hurley
Indirect proof ...
user8572
3
votes
0
answers
1k
views
Testing the validity of syllogism argument
I came across a validation method for testing the validity of a syllogistic argument which seems quite easier to grasp:
For example:
To test the argument:
no P is B
some C is B
Therefore, some ...
- 527
3
votes
1
answer
67
views
Can a variable in FOL be bound by two quantifiers if they are the same
∀x∀y((P(m) /\ Z(a,x)) > ∀xW(x,c))
Something like this. I don't think it is a sentence because the variable x is bound twice and the nested quantifier is still within the scope of the original ...
- 123
3
votes
1
answer
147
views
Is Logic Pre-Human?
It was German philosopher Martin Heidegger (1889-1976) who famously said, "animals are poor in world." Although this may be true, I do not see them as being poor in logic. Paleontologists have ...
- 1,855
3
votes
1
answer
78
views
What part of a universal propositions is the antecedent?
The wiki article on vacuous truth says:
a vacuous truth is a conditional or universal statement that is only true because the antecedent cannot be satisfied.
I'm familiar with identifying the ...
- 171
3
votes
1
answer
129
views
Given the principle of innocence, how shall we explain logic's usefulness?
I have been reading Florian Steinberger's dissertation (Harmony and logical inferentialism) and I come across the following on p60:
...two fundamental assumptions (the other one being the principle ...
3
votes
1
answer
108
views
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 ...
- 131
2
votes
0
answers
26
views
Is there a detailed doxastic logic with a doubt operator?
I was "experimenting" with a doxastic logic with a doubt operator D besides the belief operator B, trying to come up with intuitive equivalences of interleavings (e.g. DBA = BDA, perhaps), ...
- 12.4k
2
votes
0
answers
39
views
Where do presuppositions fit into Grice's theory of meaning?
To clarify, by "Grice's theory of meaning" I am referring to the view that the informational content or meaning of an utterance is made up of three components:
what is said - the actual ...
- 481
2
votes
0
answers
45
views
States-of-affairs as zero-place analogues of properties and relations?
I've been going slow through the SEP article on intrinsic properties, and came across this intriguing gem:
(The locution ‘state of affairs’ is used differently by different philosophers. Here it is ...
- 12.4k
2
votes
0
answers
59
views
Propositions vs sentence types and tokens and the context insensitivity of PL
I came across the following explanation for the context insensitivity of the language of propositiional logic (PL) on page 34 of The Laws of Truth by Nicholas Smith:
Because glossary entries pair ...
- 481
2
votes
0
answers
77
views
A question on quantified modal logic
I originally posted this on math.stackexchange.com, but I’m cross-posting it since I know there are good modal logicians on here too.
Also, I already asked a similar question here: Identity in ...
- 448
2
votes
0
answers
38
views
Existential vs. universal alternation
Is there a difference between trivial and nontrivial negation? It occurred to me that we could think of the following series of negation operations/relations:
Empty negation = primordial double-...
- 12.4k
2
votes
3
answers
114
views
Natural language into logic and proof
I'm working through Logic by Paul Tomassi, and there is one particular problem I'm stumped with. The problem is on pg 186 and involves representing an argument in English as a sequent and then ...
- 21
2
votes
0
answers
32
views
Is this a problem with verisimilitude talk, many-valued-logic talk, or something/nothing else?
A perhaps naive characterization of verisimilitude is "closeness to truth," the proximity coming from the similarity. At least, the SEP article uses, "The number of planets is 9," ...
- 12.4k
2
votes
0
answers
39
views
Bias type based on achievement of goals
What type of bias is it if I favour an idea because the implementation of the idea will benefit me? Example: I favour limited gun control despite reading contrary arguments because my livelihood is ...
- 21
2
votes
0
answers
42
views
How to prove that: ⊢/k ◻p v ◻¬p
My though it that we can refer to completeness. So just argue that ◻p v ◻¬p does not have a corresponding model. But I am not sure...
- 45
2
votes
0
answers
38
views
Substructural logic and the Continuum
The SEP article on change and inconsistency goes over a theory of continuous motion that involves true contradictions. So arguably, the dialethic/paraconsistent Continuum is one way to logically frame ...
- 12.4k
2
votes
0
answers
65
views
Questions about Feature Placing Languages/Predicate Functor Logic
About a year and nine months ago, I poses a question here about Quine's predicate functor logic and ontological nihilism. I'm still having trouble wrapping my head around these ideas. I hope someone ...
- 107
2
votes
0
answers
49
views
When does a conditional statement hold true according to Dialetheists?
I understand that for the consequent to really follow from the antecedent, it (the consequent) must be both relevant and necessary given the antecedent.
So my question is: which types of conditional ...
- 69
2
votes
0
answers
58
views
Are logical truths a subset of facts which in turn is a subset of possible truths?
Are logical truths (those that are true in all possible interpretations) a subset of facts (known via observation in our reality)? Are facts a subset of possible truths(satisfiable)? Where do axioms ...
- 360
2
votes
0
answers
126
views
Logic vs Metalogic
In Hunter's "Metalogic," the author defines metalogic as a theory of sentences used to express truths of logic, and goes onto explain model theory and proof theory.
When reading books ...
- 360
2
votes
0
answers
100
views
Can the logic used by continental philosophers like Hegel be formalized by mathematicians?
Can the logic used by continental philosophers like Hegel be formalized by mathematicians? I heard the logic used by Hegel and Heidegger is different from the logic used by analytical philosophers ...
- 3,787
2
votes
0
answers
38
views
Examples of, or counterexamples to, the concept of erotetic inference?
Suppose that the generality-particularity ordering is the comprehensive ordering on inference. Compare:
What is the first integer after 2?
What is the first prime integer after 2?
(2) would seem ...
- 12.4k
2
votes
1
answer
211
views
Are questions truth-apt; what is the use of assigning questions a truth-value?
Is John black (or white)?
Yes he is black.
No he is not (black).
I don’t see how can the question be truth-apt and what use is there in assigning (or even being able to assign) a truth-value to the ...
- 430
2
votes
0
answers
57
views
Questions about truth in deontic logic
I'm currently studying a bit of deontic logic due to a course in modal logic that I'm taking and I have some questions.
My main question is regarding truth value in deontic logic. Initially, I ...
- 21
2
votes
0
answers
62
views
Do the rules of basic logic have to presupposed to gain philosophical knowledge?
First, let me apologize if my question is nonsensical in any sense. I do not have any philosophical training whatsoever, but I am really interested in some philosophical questions.
I was thinking ...
- 171