Logic / Unit 1 Logic 013 short lesson, about 20 seconds
Validity Is About Form, Not Truth
Captions available
The idea
Validity depends on the argument's structure, not on whether its statements are actually true.
In practice
"All fish fly; whales are fish; so whales fly." Every statement false — form perfectly valid.
Where people slip
This is the single most common confusion in the entire subject. Sit with it.
Your place on the trail
Every lesson rests on earlier ones and opens later ones. Tap any to jump.
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