enthymeme

An enthymeme is a rhetorical syllogism in which one premise or the conclusion is not explicitly stated. In classical rhetoric, the missing element is supplied by the audience, who fills in the assumed general principle or result. The form relies on shared beliefs and common sense to connect the stated premise and conclusion without detailing the entire chain of reasoning.

Structure and forms: Enthymemes typically present a two-part argument with one unstated premise. The omitted premise is usually a general axiom or widely accepted truth, allowing the audience to infer the rest of the argument from the available premises and conclusion.

Examples: 1) Socrates is mortal, for he is a man. (Implied major premise: All men are mortal.) 2) This plan will work, for it is well conceived. (Implied minor premise: If a plan is well conceived, it will work.) These illustrate how the audience supplies the missing premise to complete the logical link.

History and usage: The concept traces to Aristotle and is discussed in later rhetorical manuals by figures such as Cicero and Quintilian. In rhetoric, enthymemes are valued for efficiency and persuasive force, as they engage listeners by inviting them to complete the reasoning and thus accept the conclusion.

Relation to logic: Unlike a formal syllogism with explicit premises, enthymemes are informal arguments that can be challenged if the omitted premise is questionable. They are common in everyday speech, journalism, and political discourse, where concise argumentation often relies on assumed common ground.