4 research outputs found
Probability Semantics for Aristotelian Syllogisms
We present a coherence-based probability semantics for (categorical)
Aristotelian syllogisms. For framing the Aristotelian syllogisms as
probabilistic inferences, we interpret basic syllogistic sentence types A, E,
I, O by suitable precise and imprecise conditional probability assessments.
Then, we define validity of probabilistic inferences and probabilistic notions
of the existential import which is required, for the validity of the
syllogisms. Based on a generalization of de Finetti's fundamental theorem to
conditional probability, we investigate the coherent probability propagation
rules of argument forms of the syllogistic Figures I, II, and III,
respectively. These results allow to show, for all three Figures, that each
traditionally valid syllogism is also valid in our coherence-based probability
semantics. Moreover, we interpret the basic syllogistic sentence types by
suitable defaults and negated defaults. Thereby, we build a knowledge bridge
from our probability semantics of Aristotelian syllogisms to nonmonotonic
reasoning. Finally, we show how the proposed semantics can be used to analyze
syllogisms involving generalized quantifiers