Darii-syllogisme

Leren

Een geldig syllogisme met particuliere conclusie: Alle A zijn B, Sommige C zijn A, dus Sommige C zijn B.

Darii is a first-figure syllogism that derives a particular affirmative (I) conclusion from a universal affirmative (A) major premise and a particular affirmative (I) minor premise. The name 'Darii' uses vowels A-I-I. Unlike Barbara, Darii only claims that 'some' members of a category have a property, making it useful when we know partial overlap rather than complete inclusion.

All M are P, Some S are M ⊢ Some S are P

• All birds can fly. Some pets are birds. Therefore, some pets can fly.
• All prime numbers greater than 2 are odd. Some integers are prime numbers greater than 2. Therefore, some integers are odd.
• All doctors have medical degrees. Some volunteers are doctors. Therefore, some volunteers have medical degrees.

Zo herkent u het

• Major premise uses 'All' (universal affirmative)
• Minor premise uses 'Some' (particular affirmative)
• Conclusion uses 'Some' - you cannot conclude 'All' from partial evidence

Veelgemaakte fouten

• Over-generalizing: concluding 'All' when only 'Some' is warranted
• Confusing with invalid forms where the middle term is not distributed

Oefenadvies

Logische Deductie