Logic / Unit 3 Logic 094 short lesson, about 20 seconds
Mood and Figure
Captions available
The idea
Mood is the three-letter sequence of statement forms; figure (1–4) is the middle term's position. Together they name all 256 possible syllogisms.
In practice
All M are P; All S are M; ∴ All S are P — mood AAA, figure 1. The medievals called it Barbara.
Where people slip
Of the 256, only 15 are valid on the Boolean reading. Naming forms is how you look violations up.
Your place on the trail
Every lesson rests on earlier ones and opens later ones. Tap any to jump.
Builds on
Unlocks
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