chiasmus

Chiasmus is a rhetorical device in which parallel elements are repeated in reverse order to produce a crossing, or chiastic, structure. By reversing the order of corresponding words, phrases, or clauses, chiasmus creates symmetry that highlights contrast and yields a memorable cadence. The term derives from the Greek letter chi (χ), shaped like a cross, and from the idea of crossing ideas in a sentence.

Chiasmus is broad in scope; a common form follows an ABBA pattern: A, B, B', A'. The device is often described as inverted parallelism. Antimetabole is a closely related type in which the exact words or grammatical units are repeated in reverse order, producing a mirrored clause.

Examples include: “When the going gets tough, the tough get going” (a classic ABBA chiastic structure). “Let us never negotiate out of fear, but let us never fear to negotiate.” and “Ask not what your country can do for you; ask what you can do for your country.” The latter is frequently cited as an antimetabole, illustrating how the form can meet both definitions.

Historically, chiastic patterns appear in Greek and Latin rhetoric and literature and continue in modern speech and writing. They are valued for their concise balance and rhetorical punch, aiding emphasis, rhythm, and memorability. In analysis, chiastic structures are noted as a stylistic feature that can reveal emphasis, symmetry, and thematic crossover within a text.