Logic / Unit 3 Logic 084 short lesson, about 20 seconds
Conversion
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The idea
Conversion swaps subject and predicate. Valid for E and I; invalid for A and O.
In practice
"No S are P" converts cleanly to "No P are S."
Where people slip
The A conversion is the classic wreck: "All dogs are mammals," therefore "all mammals are dogs."
Your place on the trail
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