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Questions tagged [validity]

108 questions
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Is 'guns don't kill people, people kill people' a good argument?

I'm hearing the argument X doesn't do Y people do Y in quite a few guises. For instance in it's original form guns don't kill people; people kill people Presumably, therefore guns are OK cars don't kill people; people kill people Again, the…
Crab Bucket
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Can an argument be valid even though one of its premises is false?

Is it possible for an argument to be valid by virtue of its logical form, but contain a false premise? In other words, can a premise be false even though the argument itself is logically valid? Thanks in advance! (For context: the initial question…
Curious
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Are there philosophical theories that are either confirmed or refuted by the majority of experts?

Do there exist any philosophical theories that have been either confirmed or refuted by the majority of experts? That is, confirmed or refuted such that a consensus has been established about the validity of the theory - similar to the consensus of…
Jo Wehler
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Does the Scientific Method of research apply to philosophy?

The Scientific Method is essentially the effort to discover causation in perceived correlations of collected data. In other words it hunts for 'recipes' that can be applied to consistently achieve a desired result, and as such does not inquire into…
slashmais
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Is Marx's model of capitalist society no longer valid?

Given the evolution of the capitalistic society, to what degree is Marx's model of capitalist society no longer valid nowadays ? Are there any authors which discuss the contemporary validity of Marx's work ?
ziu
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Why is Tarski's notion of logical validity preferred to deductive one?

Its flaws are well-known and serious. To recall, an inference from A to B is valid iff all interpretations of "non-logical constants" that make A true also make B true. What are interpretations, a.k.a. models or possible worlds? These are…
Conifold
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What is the difference between mathematical reasoning and philosophical reasoning?

Please see question in title. Why isn't philosophy considered to be a branch of mathematics? Is study of anything not a branch of mathematics, vague and imprecise?
John Sonderson
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What is the nature of "validity" in deduction when dealing with conclusions unrelated to premises?

I studying graduate math (not very far into it), and I realized that some of the higher-level math texts I would like to read are hard to understand without a strong basis in logic. Now I've taken elementary courses (like general college first year)…
Zduff
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What fallacy dismisses a conclusion because supporters give invalid arguments for it?

A person dismisses an otherwise valid argument, because some of its proponents support it for the wrong reason. How is this fallacy called? EDIT: Here is an example. A person defends the idea that the earth is flat. In an interview he asks several…
martinkunev
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On the Validity of Modus Tollens

One of the valid forms of argument is Modus Tollens (ie If P, then Q. Not Q, therefore, not P). An example is "If Putnam is guilty, she is lying now. She is not lying now. Therefore Putnam is not guilty." (The Elements of Reasoning - R Munson &…
Often Right
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Is there a definition of logical validity that does not rely on possible worlds?

The definition of a logically valid argument in most logic books is that an argument is valid iff there is no possible world where the premises are true and the conclusion is false. But this relies on the existence of possible worlds. For a person…
user107952
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Are "All A is B" and "If A then B" always logically equivalent?

Will "All A is B" always imply "If A then B?" If so, can we say that the following follows the form of Modus Ponens? All dogs are mammals. Toby is a dog. So, Toby is a mammal. Can I rewrite the above to be: If it is a dog, it is a mammal. Toby…
aki-02
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Where is the fallacy in Seth Yalcin's counterexample to the modus tollens?

Where is the fallacy, do you think, in Seth Yalcin’s argument (2012) that the Modus Tollens is not a generally valid form of argument? Seth Yalcin’s counterexample to the Modus Tollens…
Speakpigeon
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If the premises of an argument CANNOT all be true, then said argument is valid

Based on the fact that a deductive argument is said to be valid if and only if it takes a form that makes it impossible for the premises to be true and the conclusion nevertheless to be false, I am having trouble understanding why the statement: "If…
Ben
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Reverse Conclusion of Hypothetical Syllogism

I am presented with an argument of form: If p, then q. If q, then r. Therefore, if r, then p. Does this structure have a specific title? I know that it is invalid, and am assuming that "reverse hypothetical syllogism" is nowhere near correct.…
Ben
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