If you know all squares are rectangles and all rectangles are shapes, and you deduce from this that all squares are shapes; this is an example of syllogism.
- an argument or form of reasoning in which two statements or premises are made and a logical conclusion is drawn from them (Ex.: All mammals are warmblooded [major premise]; whales are mammals [minor premise]; therefore, whales are warmblooded [conclusion])
- reasoning from the general to the particular; deductive logic
Origin of syllogismMiddle English silogisme ; from Middle French ; from Classical Latin syllogismus ; from Classical Greek syllogismos, a reckoning together ; from syllogizesthai, to reckon together, sum up ; from syn-, together + logizesthai, to reason ; from logos, word: see logic
- 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.
- Reasoning from the general to the specific; deduction.
- A subtle or specious piece of reasoning.
Origin of syllogismMiddle 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 Indo-European roots).