Syllogism (Syllogismos) — A form of deductive reasoning in which a conclusion necessarily follows from two premises. Canonical form (Aristotle): Major premise: “All men are mortal.” / Minor premise: “Socrates is a man.” / Conclusion: “Socrates is mortal.” The syllogism was the central instrument of logic for two millennia. Frege and Russell replaced it with more powerful logical systems (propositional and predicate calculus).
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