1. Logic A form of deductive reasoning consisting of a major premise, a minor premise, and a conclusion; for example, All humans are mortal, the major premise, I am a human, the minor premise, therefore, I am mortal, the conclusion.
2. Reasoning from the general to the specific; deduction.
3. A subtle or specious piece of reasoning.
[Middle English silogisme, from Old French, from Latin syllogismus, from Greek sullogismos, from sullogizesthai, to infer : sun-, syn- + logizesthai, to count, reckon (from logos, reason; see leg- in the Appendix of Indo-European roots).]
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