Logic / Unit 3 Logic 101 short lesson, about 20 seconds
The Existential Fallacy
Captions available
The idea
On the Boolean reading, Rule 5: two universal premises cannot yield a particular conclusion — universals carry no existence, particulars assert it.
In practice
All unicorns are horned; all horned things are dangerous; ∴ some unicorns are dangerous. Existence conjured from nowhere.
Where people slip
On the Aristotelian standpoint this can pass — if the subject class is known non-empty. Standpoint first, verdict second.
Your place on the trail
Every lesson rests on earlier ones and opens later ones. Tap any to jump.
Unlocks
- Nothing yet depends on this.
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