Questions tagged [principle-of-non-contradiction]

Filter by
Sorted by
Tagged with
1 vote
3 answers
74 views

Law of non-contradiction violated [closed]

Can we consider these three examples as a violation of the law of non-contradiction? The photon (and also some other particles) is mathematically its own particle AND anti-particle The Moebius strip ...
Vincent ISOZ's user avatar
9 votes
2 answers
2k views

Is "may exist" and "may not exist" a negation that isn't a contradiction?

As usually happens, a statement (p) and its negation (~p) contradict each other. So, e.g. God does not exist, the negation of, God exists, together form a contradictory pair. A statement (p) and its ...
Agent Smith's user avatar
  • 3,196
5 votes
7 answers
2k views

How does one differentiate between the logically possible and the impossible?

The term “married bachelor” seems to be an obvious contradiction. The very definition of bachelor and unmarried are with respect to each other and so it seems nonsensical to talk about a married ...
thinkingman's user avatar
  • 8,254
2 votes
2 answers
75 views

Does Artistole's principle of non-contradiction imply/concede/allow there are contradictions, we just can't learn much via them?

From Graham Priest and the SEP it seems like the world doesn't have to be a certain way with the PNC being necessary for "scientific inquiry, reasoning and communication" (SEP). The world ...
J Kusin's user avatar
  • 2,385
2 votes
0 answers
63 views

Kant's remarks about the concept of time and the principle of noncontradiction

In the Transcendental Aesthetic he notes: ... I shall add that the conception of change, and with it the conception of motion, as change of place, is possible only through and in the representation ...
Kristian Berry's user avatar
4 votes
7 answers
2k views

Everything must have a cause?

In a possible reality, if something came into existence without something giving rise to it, the fact would be that , there was nothing stopping something from coming into existence without anything ...
loopit's user avatar
  • 119
3 votes
6 answers
331 views

A resolution to liar's paradox

Let's consider the famous liar paradox's statement: This statement is false Now, in classical logic, principle of bivalence could be stated as "All statements can either be assigned a value of ...
Siddharth Chakravarty's user avatar
2 votes
0 answers
36 views

Would a universal (tran)set violate the law of identity?

At least, here's the argument that opened the question for me: The anticlass-theory principle: there are no discrete proper classes. There are intensional elementhood parameters such that if some set ...
Kristian Berry's user avatar
6 votes
1 answer
168 views

What is ⊥ called in paraconsistent logic?

I am building a weakened version of the intuitionistic logic. It wouldn't satisfy (p∧¬p)→⊥ as a tautology, but rather, (⊤→(p∧¬p))→⊥. In plain English, contradictions admit no proof, but there might ...
Dannyu NDos's user avatar
3 votes
3 answers
193 views

"Impredicative" definitions in mathematics

In this blog post, the following definition of an "impredicative definition" is offered: A definition is said to be impredicative if it defines an object E by means of a quantification over a ...
Frank's user avatar
  • 2,405
1 vote
0 answers
26 views

Transconsistency operators and degrees of logical explosivity?

So I noticed in an article I was reading that they talked about consistency and/or inconsistency or otherwise transconsistency operators. I don't recall the details, but they sound like propositional ...
Kristian Berry's user avatar
0 votes
0 answers
72 views

Do there exist ideas which are true beyond axiom systems?

I find that sometimes there are many systems in which one could prove/ describe a single idea given in Mathematics. This made me wonder, is the thing we are proving actually true beyond the proof ...
tryst with freedom's user avatar
2 votes
2 answers
79 views

What could be some general unifying principles to guide what a philosophical reflection/enquiry might look like?

The notions of logical consistency, pertinence and possibly relevance seem important for a philosophical inquiry on some matter to be fruitful and interesting. Other notions once considered important, ...
Davius's user avatar
  • 641
1 vote
2 answers
173 views

How to understand a proof by contradiction in minute detail?

I am following the course "Language, Proof, and Logic" from Stanford on EdX. I am trying to understand proof by contradiction specifically. I understand the gist of this type of proof, and I ...
evianpring's user avatar
4 votes
3 answers
365 views

Can a category of non-difference exist in Western logic?

Indian philosophy has a logical category of non-difference (related somewhat to abheda) in which something is different from something else but identical to it as well. An example is that of the the ...
Amala's user avatar
  • 143
1 vote
1 answer
84 views

Relationship between Principle of sufficient reason and Law of identity [closed]

I have an intuition that one can derive the principle of sufficient reason from the law of identity or non-contradiction but i don't know how. If someone knows I'd like some help.
Yassine Sifeddine's user avatar
14 votes
12 answers
12k views

Why is it that the statement "All goblins are yellow" does not contradict the statement "All goblins are pink?"

From what I know, I think it has something to do with vacuous truths, but my understanding is not quite there yet.
loopzoop's user avatar
  • 304
1 vote
3 answers
164 views

Why law of identity is formulated in terms of "things" and not statements?

The law of non-contradiction (LNC) and law of excluded middle (LEM) are both formulated in terms of statements. That is "A and not A" is always false and "A or not A" is always ...
ado sar's user avatar
  • 691
3 votes
4 answers
590 views

Can we know that law of non contradiction is true a priori?

I have seen some arguments for why should we accept law of non contradiction, and it seems to works in almost all areas. But some argument for it is like an argument for principle "nothing comes from ...
Hare Krishna's user avatar
5 votes
4 answers
431 views

Where did Suárez say the principle of non-contradiction does not apply to the Trinity?

Fr. Réginald Garrigou-Lagrange, O.P., says, in Le Sens du Mystère et le Clair-Obscur Intellectuel: Nature et Surnaturel p. 128 fn. 1 (Engl. transl. p. 142 fn. 41): St. Thomas never would have ...
Geremia's user avatar
  • 7,817
4 votes
3 answers
786 views

How do Thomists prove that: "Everything that exists must exist by something."?

One variation of principle of sufficient reason that Thomists use is: Everything that exists must exist by something. How do they prove such a statement? In particular, why can not something just ...
Thom's user avatar
  • 288