The Art of Logic · Part 13 · Reasoning · B2–C1
Enthymeme, Sorites and Epicheirema
Part 13 of The Art of Logic: real arguments rarely state every premise. The missing one is often the weakest, and the most persuasive, because nobody examines it. Implying and inferring (imply, infer, assume, take for granted), with Philo, Sophia, Marcos and Demetria.
Almost never in full. They say “Socrates is a man, so he’s mortal”, and leave the first premise unsaid.
Sometimes. And sometimes because, said aloud, it would sound ridiculous.
An enthymeme is a syllogism with one part left unstated: the major premise, the minor premise, or even the conclusion. “He’s a doctor, so his medicine must work” leaves out the major premise: “All doctors’ medicines work.” Aristotle called the enthymeme the syllogism of rhetoric, because speakers use it constantly, and listeners supply the missing part themselves.
A sorites is a chain of syllogisms with the intermediate conclusions left out: all A are B, all B are C, all C are D, so all A are D. An epicheirema is a syllogism in which a reason is attached to one or both premises: “All gamblers are poor, because they lose more than they win; Marcos is a gambler, because he bets on the races; so Marcos is poor.”
Sister Miriam Joseph’s advice: to test an enthymeme, supply the missing premise, say it aloud, and ask whether it is true.
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