commonplaces

Commonplaces are conventional ideas, phrases, or themes that can be used as starting points in argument, writing, or speech. In rhetoric, a commonplace (plural commonplaces) refers to a topos—a familiar proposition or line of reasoning that listeners are presumed to recognize and accept. Speakers and writers draw upon commonplaces to connect new claims with widely held beliefs, to establish credibility, or to organize a discourse around recognizable patterns such as cause and effect, precedent, or moral virtue. The concept originates in classical rhetoric and is tied to the idea of cognitive anchors or shared cultural assumptions; the Latin term locus commune roughly translates as "common place."

In practice, commonplaces also appear as stock arguments or ready-made lines that can be adapted to different topics. The related practice of compiling commonplaces—often in a commonplace book—enabled authors to collect quotations, maxims, and thematic passages for future reference, assisting memory and writing.

In modern usage, commonplace can refer more broadly to widely accepted beliefs or clichés—what one might call common wisdom or platitudes. The term can carry a neutral sense when describing a standard argumentative tool, or pejorative when criticizing overused or unoriginal rhetoric. Overall, commonplaces reflect how shared knowledge and familiar argumentative patterns shape discourse across historical periods.