Skip to main content
34 votes

Can an argument be valid even though one of its premises is false?

First: we don't really say that arguments are true or false. Statements are true or false, but arguments have different kinds of properties. One of those properties is, as you are obviously aware of, ...
Bram28's user avatar
  • 2,719
21 votes

Can an argument be valid even though one of its premises is false?

Yes : Premise : All dogs are mortal (true) Premise : All birds are dogs (false) Conclusion : All birds are mortal (true) The argument is valid because there is a correct relation between premises ...
Geoffrey Thomas's user avatar
  • 35.8k
17 votes

Can an argument be valid even though one of its premises is false?

(Promoting this from @MauroALLEGRANZA's comment, since it deserves a full answer.) Yes, an argument can be valid but still not be sound. This is really just a matter of understanding the terminology: ...
BradC's user avatar
  • 439
14 votes
Accepted

Is Romans 1:19-20 philosophically sound?

St Paul is referring to pagans who recognized God through natural theology, not to anybody indiscriminately, even if knowing God through natural theology is theoretically possible for anyone with ...
Mutoh's user avatar
  • 756
14 votes
Accepted

Is "(1) All humans are mortal. (2) Socrates is mortal. Conclusion: Socrates is human." unsound argument?

Hence, I think this one is a sound sentence. Soundness is not a property that applies to sentences, but rather to arguments as whole. A sound argument is one that is valid and has all true premises. ...
transitionsynthesis's user avatar
11 votes
Accepted

Example of an unsound argument with true premise and true conclusions

The sky is blue Therefore, grass is green. The premise and the conclusion are both true. But the argument is not sound, because it's not valid. And it's not valid because the conclusion doesn't ...
E...'s user avatar
  • 6,556
9 votes

Is Romans 1:19-20 philosophically sound?

Aside from a lack of philosophical argument in the verse you posted (which I’m sure someone else will answer), there is actually a philosophical debate about how God is hidden, rather than being “...
notwithstanding's user avatar
6 votes

Is Romans 1:19-20 philosophically sound?

From a philosophical point of view one may ask the following questions concerning soundness: How to conclude from observations in the world to a creator of the world? The author speaking about God ...
Jo Wehler's user avatar
  • 33.5k
5 votes

Is Romans 1:19-20 philosophically sound?

Although Kant was somewhat fond, even in his critical period, of the teleological argument for God's existence, he made sure to emphasize the gap between the designer such an argument's grounds ...
Kristian Berry's user avatar
5 votes

Is Romans 1:19-20 philosophically sound?

The biggest problem there is the questionable assertions / premises. The actual argument is not that meaningful. We can take the original verse: 19 For what can be known about God is plain to them, ...
NotThatGuy's user avatar
  • 10.9k
5 votes

How can logical soundness be determined, if it is the rules of the logic itself which dictate what is true and false?

The idea of soundness has two different flavours, and perhaps you are confusing them. A logical argument can be sound if the logical is correctly applied and the premises are true. For example: All ...
Marco Ocram's user avatar
  • 23.5k
4 votes

Is Romans 1:19-20 philosophically sound?

The standpoint presented by Paul comes from earlier text of Wisdom of Salomon 13 1-9: 1.For all men were by nature foolish who were in ignorance of God, and who from the good things seen did not ...
Jakub Lorenc's user avatar
4 votes

Is Romans 1:19-20 philosophically sound?

Does the universe clearly point to an Almighty Creator? This is indeed the crux of the argument. If true (as Paul clearly asserts), the rest of Paul's argument holds. If false, Paul is talking ...
Matthew's user avatar
  • 439
3 votes

Can an argument be valid even though one of its premises is false?

It sounds like you are trying to ask if you can have logical premises that are false, yet support a conclusion that is true - in other words, an example of presenting facts that lead to a true ...
Zibbobz's user avatar
  • 271
3 votes
Accepted

How can a proof system be unsound?

Soundness If Δ ⊢ Φ, then Δ ⊨ Φ has an implicit universal quantification to it: For all Δ, Φ: if Δ ⊢ Φ, then Δ ⊨ Φ Unsoundness of a proof system then means Not for all Δ, Φ: if Δ ⊢ Φ, then Δ ⊨ Φ ...
Natalie Clarius's user avatar
3 votes

Counterfactuals in Premises for Arguments

Counterfactual conditionals do appear in arguments, and we tend to treat them as contributing to validity and soundness, but their logic is much more problematic than other conditionals. Consider, for ...
Bumble's user avatar
  • 26.3k
3 votes
Accepted

Soundness of a deductive argument

The answer to this question depends in part of the symbolization resources you have available to you. If we translate as follows: Anything that travels in time necessarily changes the past to T -...
virmaior's user avatar
  • 24.8k
3 votes
Accepted

How does one prove properties of soundness and completeness for a logic using proof-theoretic semantics?

One typically does not, soundness and completeness are not particularly natural properties from the proof-theoretic point of view. Although rarely spelled out explicitly, there is in the background ...
Conifold's user avatar
  • 43.5k
3 votes

Is Propositional Logic Sound and Complete

Yes, you can give axioms and rules of inference so that all and only the tautologies are derivable. Propositional calculus is better behaved than first order logic in that sense. That doesn't mean you ...
Bjørn Kjos-Hanssen's user avatar
2 votes

Is "(1) All humans are mortal. (2) Socrates is mortal. Conclusion: Socrates is human." unsound argument?

The argument is not sound because there could be things named Socrates that are mortal that are not human- for instance, my cat is named Socrates, and he's definitely not human. A sound argument ...
Eddie's user avatar
  • 21
2 votes

Is "(1) All humans are mortal. (2) Socrates is mortal. Conclusion: Socrates is human." unsound argument?

Premise 1: All humans are mortal. Premise 2: Socrates is mortal. Conclusion: Socrates is human. This reasoning is unsound because the middle term (mortal) is undistributed. Thus there is no ...
Mark Andrews's user avatar
  • 6,314
2 votes

Is Propositional Logic Sound and Complete

Goedel's 1930 completeness theorem showed that first-order predicate calculus is complete in the sense that every valid formula is a theorem. There are many calculi that have as theorems all and only ...
Paul E. Oppenheimer's user avatar
2 votes

Can an argument be valid even though one of its premises is false?

I think that you're confusing validity and soundness. The validity of an argument is determined purely by its form, not by whether or not its premises are true. On the other hand, a sound deductive ...
EJoshuaS - Stand with Ukraine's user avatar
2 votes
Accepted

If an argument cannot be known as sound, can it still be claimed as sound?

The purpose of arguments is, roughly speaking, to convince people of things. More specifically, the purpose of an argument is to convince someone of the conclusion, based on premises that they accept ...
NotThatGuy's user avatar
  • 10.9k
2 votes

Is Romans 1:19-20 philosophically sound?

Yes, the argument is quite sound. Though it is written in context of God's knowledge known to all nations, it also fits well even to the modern atheist culture which is based on naturalism, or on the ...
Michael16's user avatar
  • 135
1 vote

If an argument cannot be known as sound, can it still be claimed as sound?

However, what if no one can know whether or not an argument is sound because no one can evaluate its claim as valid and its premises are true?... why is it that if an argument cannot be known as sound ...
J D's user avatar
  • 28.2k
1 vote

Does this argument disprove immaterialism?

Immaterial causes are unfalsifiable, so your argument doesn't/can't falsify them. It just tries to convince, but cannot prove anything. The first part is also questionable. There are plenty of things ...
kutschkem's user avatar
  • 2,320
1 vote
Accepted

In logic, can we or can we not prove that a formula is invalid?

The definitions are relevant to a Logical system and can be extended to Formal mathematical theories. See the Wiki's page (some lines below your quote): Soundness of a deductive system is the ...
Mauro ALLEGRANZA's user avatar
1 vote

Can an argument be valid even though one of its premises is false?

Technically, in all classical, standard logics, if an argument with any number of true premises is valid, its conclusion must be true as well, based on the fixed meaning of the logical constants ...
A. ter Meulen's user avatar
1 vote

Can an argument be valid even though one of its premises is false?

As well as soundness and validity and such, it may also be worth considering that an argument can (although it may be considered poor form) have redundancies. In that case, it could be that one false ...
Josiah's user avatar
  • 1,873

Only top scored, non community-wiki answers of a minimum length are eligible