syllogism

SIL-uh-jiz-um /ˈsɪl.ə.dʒɪz.əm/
nounC1GRESAT
academicformal

A form of deductive reasoning consisting of a major premise, a minor premise, and a conclusion.

Describes a very specific three-part logical structure (e.g., 'All humans are mortal; Socrates is human; therefore Socrates is mortal').

The story behind the word. Aristotle formalized the logic of combining terms in Greece during the 4th century BCE. The Greek 'syllogismos' literally meant 'gathering thoughts together' or 'bringing reasons together' to yield a necessary conclusion.

Word relationships

  • deductive argument: A deductive argument is a broader term, whereas a syllogism is a specific three-proposition form.
  • enthymeme: An enthymeme is an argument in which one premise is implied rather than explicitly stated.

Commonly confused with

  • sophistry: A syllogism is a neutral structural tool of logic, whereas sophistry is intentionally misleading argument.

Word family

  • syllogistic (adjective): Relating to or consisting of a syllogism.
  • syllogistically (adverb): In the manner of a syllogism.

Collocations

  • categorical syllogism
  • hypothetical syllogism
  • construct a syllogism

Example sentences

  • "A syllogism is discourse in which, certain things being stated, something else follows of necessity from their being so." Classical Logic (Aristotle, Prior Analytics)
  • "The professor illustrated valid reasoning by writing a classic categorical syllogism on the chalkboard." Academic Writing

Memory hook

Think of SYLLABUS + LOGIC: a syllogism packages logic into a neat three-step syllabus. Bringing two premises together into one conclusion.

When not to use

Do not use to describe informal arguments, wild guesses, or complex multi-step mathematical proofs.

Fun facts

  • Lewis Carroll, author of Alice in Wonderland, was a mathematician who wrote entire books of humorous, absurd syllogisms for children.

Related words

premise, deduction, valid

Explore more words

deduce, premise, inference, fallacy, infer

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