Logic / Unit 3 Logic 080 short lesson, about 20 seconds
Contraries
Captions available
The idea
A and E are contraries: they cannot both be true, but can both be false.
In practice
"All voters approve" and "No voters approve" — both false when opinion splits.
Where people slip
Traditional doctrine only. The Boolean interpretation drops this relation entirely.
Your place on the trail
Every lesson rests on earlier ones and opens later ones. Tap any to jump.
Builds on
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