Truth and validity seem like the same thing in an argument, and it is exactly this confusion that makes so many people leave a conversation feeling like they lost to someone who was wrong. They are two different questions, and learning to separate them dismantles half of the twisted reasoning that exists.
Two questions, not one
Validity asks about structure: if the premises of an argument were true, would the conclusion necessarily follow from them? It's a matter of logical fit, not fact. Truth asks about content: do the premises really correspond to reality? It is a question about the world, not about the form of reasoning.
The crucial point is that these two things vary independently of each other.
When form deceives
An argument can have a perfectly valid structure and still be false, because the premise is false: all fish fly; salmon is fish; therefore, the salmon flies. The logical fit is impeccable, the "therefore" works, and the conclusion is absurd, because the first statement does not correspond to reality.
And there is the opposite path: a person can reach a true conclusion through an invalid path, that is, by luck, and this is not reasoning, it is guessing. An ad like "successful people wake up at five in the morning; therefore, if you wake up at five, you will be successful" may even have true premises, but the "logo" is crooked, because it confuses what merely accompanies a result with what causes it.
Why this distinction resolves arguments
When someone leaves a discussion feeling that the other was wrong, but without knowing where, the error almost always lives here: either in a false premise dressed up as obvious, or in a "logo" that doesn't hold up. Learning to separate these two questions, and always asking them together, is what turns "I felt like something was wrong" into "here's exactly what's wrong."
Only the argument that brings together the two things is solid: true premises and valid structure. It is this demanding standard that separates reliable reasoning from a fallacy well-worn, and is the nucleus of all the logic discussed in premises, conclusion and validity.
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What is the difference between truth and validity?
Validity assesses the structure of the argument: if the premises were true, would the conclusion follow from them? Truth evaluates content: do the premises really correspond to reality? They are independent questions.
Is a valid argument always true?
No. "All fish fly; salmon are fish; therefore, salmon fly" has valid structure, but the premise is false, so the conclusion is also false, despite the perfect form.
What makes a solid argument?
The meeting of two things at the same time, true premises and valid structure. If any one is missing, the argument may convince, but it does not guarantee the truth of the conclusion.
Continue in the cluster of this class: Premises, conclusion and validity · What is a syllogism · What is a premise
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