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Enthymeme
A syllogism in which one premise (or sometimes the conclusion) is left unstated and must be supplied by the reader.
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A syllogism in which one premise (or sometimes the conclusion) is left unstated and must be supplied by the reader.
An enthymeme is a classical rhetorical argument structured like a syllogism but with a hidden (suppressed) premise. Aristotle called it 'the body of proof' and treated it as the rhetorical counterpart of the syllogism in the Rhetoric. To evaluate an enthymeme, the reader must identify the missing premise and check whether the completed argument is valid. Everyday reasoning relies heavily on enthymemes because fully explicit syllogisms are rare in ordinary speech.
Stated: P1, ∴ C. Reconstructed: P1, (P2 implicit), ∴ C
- 'Socrates is mortal, because he is a man' — hidden premise: all men are mortal
- 'She must have a key — the door is open' — hidden premise: only key-holders open this door
- 'This coin is unfair, so we should test it' — hidden premise: unfair coins should be tested
How to recognize it
- Only one premise is stated alongside the conclusion
- The argument 'feels' suggestive rather than formally complete
- Trigger words: 'because', 'so', 'therefore' with only one supporting claim
Common mistakes
- Accepting the enthymeme without reconstructing the missing premise
- Supplying a premise that makes the argument trivially valid (question-begging)
- Treating any short argument as an enthymeme — some are simply incomplete